61 results on '"Birgit Nikolay"'
Search Results
2. Seroprevalence of SARS-CoV-2 antibodies and retrospective mortality in two African settings: Lubumbashi, Democratic Republic of the Congo and Abidjan, Côte d’Ivoire
- Author
-
Erica Simons, Birgit Nikolay, Pascal Ouedraogo, Estelle Pasquier, Carlos Tiemeni, Ismael Adjaho, Colette Badjo, Kaouther Chamman, Mariam Diomandé, Mireille Dosso, Moussa Doumbia, Yves Asuni Izia, Hugues Kakompe, Anne Marie Katsomya, Vicky Kij, Viviane Kouakou Akissi, Christopher Mambula, Placide Mbala-Kingebeni, Jacques Muzinga, Basile Ngoy, Lou Penali, Alessandro Pini, Klaudia Porten, Halidou Salou, Daouda Sevede, Francisco Luquero, and Etienne Gignoux
- Subjects
Public aspects of medicine ,RA1-1270 - Abstract
Although seroprevalence studies have demonstrated the wide circulation of SARS-COV-2 in African countries, the impact on population health in these settings is still poorly understood. Using representative samples of the general population, we evaluated retrospective mortality and seroprevalence of anti-SARS-CoV-2 antibodies in Lubumbashi and Abidjan. The studies included retrospective mortality surveys and nested anti-SARS-CoV-2 antibody prevalence surveys. In Lubumbashi the study took place during April-May 2021 and in Abidjan the survey was implemented in two phases: July-August 2021 and October-November 2021. Crude mortality rates were stratified between pre-pandemic and pandemic periods and further investigated by age group and COVID waves. Anti-SARS-CoV-2 seroprevalence was quantified by rapid diagnostic testing (RDT) and laboratory-based testing (ELISA in Lubumbashi and ECLIA in Abidjan). In Lubumbashi, the crude mortality rate (CMR) increased from 0.08 deaths per 10 000 persons per day (pre-pandemic) to 0.20 deaths per 10 000 persons per day (pandemic period). Increases were particularly pronounced among
- Published
- 2023
3. Analytical framework to evaluate and optimize the use of imperfect diagnostics to inform outbreak response: Application to the 2017 plague epidemic in Madagascar.
- Author
-
Quirine Ten Bosch, Voahangy Andrianaivoarimanana, Beza Ramasindrazana, Guillain Mikaty, Rado J L Rakotonanahary, Birgit Nikolay, Soloandry Rahajandraibe, Maxence Feher, Quentin Grassin, Juliette Paireau, Soanandrasana Rahelinirina, Rindra Randremanana, Feno Rakotoarimanana, Marie Melocco, Voahangy Rasolofo, Javier Pizarro-Cerdá, Anne-Sophie Le Guern, Eric Bertherat, Maherisoa Ratsitorahina, André Spiegel, Laurence Baril, Minoarisoa Rajerison, and Simon Cauchemez
- Subjects
Biology (General) ,QH301-705.5 - Abstract
During outbreaks, the lack of diagnostic "gold standard" can mask the true burden of infection in the population and hamper the allocation of resources required for control. Here, we present an analytical framework to evaluate and optimize the use of diagnostics when multiple yet imperfect diagnostic tests are available. We apply it to laboratory results of 2,136 samples, analyzed with 3 diagnostic tests (based on up to 7 diagnostic outcomes), collected during the 2017 pneumonic (PP) and bubonic plague (BP) outbreak in Madagascar, which was unprecedented both in the number of notified cases, clinical presentation, and spatial distribution. The extent of these outbreaks has however remained unclear due to nonoptimal assays. Using latent class methods, we estimate that 7% to 15% of notified cases were Yersinia pestis-infected. Overreporting was highest during the peak of the outbreak and lowest in the rural settings endemic to Y. pestis. Molecular biology methods offered the best compromise between sensitivity and specificity. The specificity of the rapid diagnostic test was relatively low (PP: 82%, BP: 85%), particularly for use in contexts with large quantities of misclassified cases. Comparison with data from a subsequent seasonal Y. pestis outbreak in 2018 reveal better test performance (BP: specificity 99%, sensitivity: 91%), indicating that factors related to the response to a large, explosive outbreak may well have affected test performance. We used our framework to optimize the case classification and derive consolidated epidemic trends. Our approach may help reduce uncertainties in other outbreaks where diagnostics are imperfect.
- Published
- 2022
- Full Text
- View/download PDF
4. Serologic response to SARS-CoV-2 in an African population
- Author
-
Karl Njuwa Fai, Tchoula Mamiafo Corine, Lisa M. Bebell, Akenji Blaise Mboringong, E.B.P. Taa Nguimbis, Robert Nsaibirni, Nicole Fouda Mbarga, Lucrece Eteki, Birgit Nikolay, Rene Ghislain Essomba, Mark Ndifon, Rodrigue Ntone, Achta Hamadou, Lucrece Matchim, Dora Tchiasso, Aristide S. Abah Abah, Rachel Essaka, Solange Peppa, Fouda Crescence, Jean Patrick Ouamba, Modeste Tamakloé Koku, Nadia Mandeng, Mahamat Fanne, Sarah Eyangoh, Georges Alain Etoundi Mballa, Linda Esso, Emilienne Epée, Richard Njouom, Marie-Claire Okomo Assoumou, and Yap Boum
- Subjects
COVID-19 ,Serology ,Rapid diagnostic tests ,Immunoglobulin ,Africa ,Science - Abstract
Official case counts suggest Africa has not seen the expected burden of COVID-19 as predicted by international health agencies, and the proportion of asymptomatic patients, disease severity, and mortality burden differ significantly in Africa from what has been observed elsewhere. Testing for SARS-CoV-2 was extremely limited early in the pandemic and likely led to under-reporting of cases leaving important gaps in our understanding of transmission and disease characteristics in the African context. SARS-CoV-2 antibody prevalence and serologic response data could help quantify the burden of COVID-19 disease in Africa to address this knowledge gap and guide future outbreak response, adapted to the local context. However, such data are widely lacking in Africa. We conducted a cross-sectional seroprevalence survey among 1,192 individuals seeking COVID-19 screening and testing in central Cameroon using the Innovita antibody-based rapid diagnostic. Overall immunoglobulin prevalence was 32%, IgM prevalence was 20%, and IgG prevalence was 24%. IgM positivity gradually increased, peaking around symptom day 20. IgG positivity was similar, gradually increasing over the first 10 days of symptoms, then increasing rapidly to 30 days and beyond. These findings highlight the importance of diagnostic testing and asymptomatic SARS-CoV-2 transmission in Cameroon, which likely resulted in artificially low case counts. Rapid antibody tests are a useful diagnostic modality for seroprevalence surveys and infection diagnosis starting 5-7 days after symptom onset. These results represent the first step towards better understanding the SARS-CoV-2 immunological response in African populations.
- Published
- 2021
- Full Text
- View/download PDF
5. Seroprevalence and risk factors of exposure to COVID-19 in homeless people in Paris, France: a cross-sectional study
- Author
-
Thomas Roederer, MSc, Bastien Mollo, MD, Charline Vincent, MSc, Birgit Nikolay, PhD, Augusto E Llosa, PhD, Robin Nesbitt, PhD, Jessica Vanhomwegen, PhD, Thierry Rose, PhD, Sophie Goyard, PhD, François Anna, PhD, Corinne Torre, MSc, Emilie Fourrey, MPH, Erica Simons, MPh, William Hennequin, MSc, Clair Mills, MD, and Francisco J Luquero, PhD
- Subjects
Public aspects of medicine ,RA1-1270 - Abstract
Summary: Background: During the COVID-19 lockdown period from March 17 to May 11, 2020, French authorities in Paris and its suburbs relocated people experiencing recurrent homelessness to emergency shelters, hotels, and large venues. A serological survey was done at some of these locations to assess the COVID-19 exposure prevalence in this group. Methods: We did a cross-sectional seroprevalence study at food distribution sites, emergency shelters, and workers' residences that were provided medical services by Médecins Sans Frontières in Paris and Seine-Saint-Denis in the Ile-de-France region. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody seropositivity was detected by Luciferase-Linked Immunosorbent Assay and Pseudo Neutralization Test. Sociodemographic and exposure related information was collected via a verbal questionnaire to analyse risk factors and associations with various COVID-19 symptoms. Findings: Between June 23 and July 2, 2020, 426 (52%) of 818 individuals recruited tested positive in 14 sites. Seroprevalence varied significantly by type of recruitment site (χ2 p
- Published
- 2021
- Full Text
- View/download PDF
6. Social and environmental risk factors for dengue in Delhi city: A retrospective study.
- Author
-
Olivier Telle, Birgit Nikolay, Vikram Kumar, Samuel Benkimoun, Rupali Pal, B N Nagpal, and Richard E Paul
- Subjects
Arctic medicine. Tropical medicine ,RC955-962 ,Public aspects of medicine ,RA1-1270 - Abstract
Global urbanization is leading to an inexorable spread of several major diseases that need to be stemmed. Dengue is one of these major diseases spreading in cities today, with its principal mosquito vector superbly adapted to the urban environment. Current mosquito control strategies are proving inadequate, especially in the face of such urbanisation and novel, evidence-based targeted approaches are needed. Through combined epidemiological and entomological approaches, we aimed to identify a novel sanitation strategy to alleviate the burden of dengue through how the dengue virus spreads through the community. We combined surveillance case mapping, prospective serological studies, year-round mosquito surveys, socio-economic and Knowledge Attitudes and Practices surveys across Delhi. We identified lack of access to tap water (≤98%) as an important risk factor for dengue virus IgG sero-positivity (adjusted Odds Ratio 4.69, 95% C.I. 2.06-10.67) and not poverty per se. Wealthier districts had a higher dengue burden despite lower mosquito densities than the Intermediary income communities (adjusted Odds Ratio 2.92, 95% C.I. 1.26-6.72). This probably reflects dengue being introduced by people travelling from poorer areas to work in wealthier houses. These poorer, high density areas, where temperatures are also warmer, also had dengue cases during the winter. Control strategies based on improved access to a reliable supply of tap water plus focal intervention in intra-urban heat islands prior to the dengue season could not only lead to a reduction in mosquito abundance but also eliminate the reservoir of dengue virus clearly circulating at low levels in winter in socio-economically disadvantaged areas.
- Published
- 2021
- Full Text
- View/download PDF
7. A quantitative comparison of West Nile virus incidence from 2013 to 2018 in Emilia-Romagna, Italy.
- Author
-
Giovanni Marini, Mattia Calzolari, Paola Angelini, Romeo Bellini, Silvia Bellini, Luca Bolzoni, Deborah Torri, Francesco Defilippo, Ilaria Dorigatti, Birgit Nikolay, Andrea Pugliese, Roberto Rosà, and Marco Tamba
- Subjects
Arctic medicine. Tropical medicine ,RC955-962 ,Public aspects of medicine ,RA1-1270 - Abstract
BackgroundWest Nile virus (WNV) transmission was much greater in 2018 than in previous seasons in Europe. Focusing on Emilia-Romagna region (northern Italy), we analyzed detailed entomological and epidemiological data collected in 2013-2018 to quantitatively assess environmental drivers of transmission and explore hypotheses to better understand why the 2018 epidemiological season was substantially different than the previous seasons. In particular, in 2018 WNV was detected at least two weeks before the observed circulation in 2013-2017 and in a larger number of mosquito pools. Transmission resulted in 100 neuroinvasive human cases in the region, more than the total number of cases recorded between 2013 and 2017.MethodologyWe used temperature-driven mathematical models calibrated through a Bayesian approach to simulate mosquito population dynamics and WNV infection rates in the avian population. We then estimated the human transmission risk as the probability, for a person living in the study area, of being bitten by an infectious mosquito in a given week. Finally, we translated such risk into reported WNV human infections.Principal findingsThe estimated prevalence of WNV in the mosquito and avian populations were significantly higher in 2018 with respect to 2013-2017 seasons, especially in the eastern part of the region. Furthermore, peak avian prevalence was estimated to have occurred earlier, corresponding to a steeper decline towards the end of summer. The high mosquito prevalence resulted in a much greater predicted risk for human transmission in 2018, which was estimated to be up to eight times higher than previous seasons. We hypothesized, on the basis of our modelling results, that such greater WNV circulation might be partially explained by exceptionally high spring temperatures, which have likely helped to amplify WNV transmission at the beginning of the 2018 season.
- Published
- 2020
- Full Text
- View/download PDF
8. Role of Environmental Factors in Shaping Spatial Distribution of Salmonella enterica Serovar Typhi, Fiji
- Author
-
Ruklanthi de Alwis, Conall Watson, Birgit Nikolay, John H. Lowry, Nga Tran Vu Thieu, Tan Trinh Van, Dung Tran Thi Ngoc, Kitione Rawalai, Mere Taufa, Jerimaia Coriakula, Colleen L. Lau, Eric J. Nilles, W. John Edmunds, Mike Kama, Stephen Baker, and Jorge Cano
- Subjects
Salmonella enterica serovar Typhi ,bacteria ,typhoid fever ,environmental factors ,risk factors ,multilevel analysis ,Medicine ,Infectious and parasitic diseases ,RC109-216 - Abstract
Fiji recently experienced a sharp increase in reported typhoid fever cases. To investigate geographic distribution and environmental risk factors associated with Salmonella enterica serovar Typhi infection, we conducted a cross-sectional cluster survey with associated serologic testing for Vi capsular antigen–specific antibodies (a marker for exposure to Salmonella Typhi in Fiji in 2013. Hotspots with high seroprevalence of Vi-specific antibodies were identified in northeastern mainland Fiji. Risk for Vi seropositivity increased with increased annual rainfall (odds ratio [OR] 1.26/quintile increase, 95% CI 1.12–1.42), and decreased with increased distance from major rivers and creeks (OR 0.89/km increase, 95% CI 0.80–0.99) and distance to modeled flood-risk areas (OR 0.80/quintile increase, 95% CI 0.69–0.92) after being adjusted for age, typhoid fever vaccination, and home toilet type. Risk for exposure to Salmonella Typhi and its spatial distribution in Fiji are driven by environmental factors. Our findings can directly affect typhoid fever control efforts in Fiji.
- Published
- 2018
- Full Text
- View/download PDF
9. Changes in the Transmission Dynamic of Chikungunya Virus in Southeastern Senegal
- Author
-
Abdourahmane Sow, Birgit Nikolay, Oumar Faye, Simon Cauchemez, Jorge Cano, Mawlouth Diallo, Ousmane Faye, Bakary Sadio, Oumar Ndiaye, Scott C. Weaver, Anta T. Dia, Amadou Alpha Sall, and Denis Malvy
- Subjects
chikungunya ,spatial autocorrelation ,environmental risk ,gold mining ,senegal ,Microbiology ,QR1-502 - Abstract
In Senegal, chikungunya virus (CHIKV) is maintained in a sylvatic cycle and causes sporadic cases or small outbreaks in rural areas. However, little is known about the influence of the environment on its transmission. To address the question, 120 villages were randomly selected in the Kedougou region of southeastern Senegal. In each selected village, 10 persons by randomly selected household were sampled and tested for specific anti-CHIKV IgG antibodies by ELISA. We investigated the association of CHIKV seroprevalence with environmental variables using logistic regression analysis and the spatial correlation of village seroprevalence based on semivariogram analysis. Fifty-four percent (51%−57%) of individuals sampled during the survey tested positive for CHIKV-specific IgG. CHIKV seroprevalence was significantly higher in populations living close to forested areas (Normalized Difference Vegetation Index (NDVI), Odds Ratio (OR) = 1.90 (1.42−2.57)), and was negatively associated with population density (OR = 0.76 (0.69−0.84)). In contrast, in gold mining sites where population density was >400 people per km2, seroprevalence peaked significantly among adults (46% (27%−67%)) compared to all other individuals (20% (12%−31%)). However, traditional gold mining activities significantly modify the transmission dynamic of CHIKV, leading to a potential increase of the risk of human exposition in the region.
- Published
- 2020
- Full Text
- View/download PDF
10. Modelling the distribution and transmission intensity of lymphatic filariasis in sub-Saharan Africa prior to scaling up interventions: integrated use of geostatistical and mathematical modelling
- Author
-
Paula Moraga, Jorge Cano, Rebecca F. Baggaley, John O. Gyapong, Sammy M. Njenga, Birgit Nikolay, Emmanuel Davies, Maria P. Rebollo, Rachel L. Pullan, Moses J. Bockarie, T. Déirdre Hollingsworth, Manoj Gambhir, and Simon J. Brooker
- Subjects
Lymphatic filariasis ,Wuchereria bancrofti ,Bayesian geostatistical modelling ,Mathematical modelling ,Basic reproductive number ,Sub-Saharan Africa ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Lymphatic filariasis (LF) is one of the neglected tropical diseases targeted for global elimination. The ability to interrupt transmission is, partly, influenced by the underlying intensity of transmission and its geographical variation. This information can also help guide the design of targeted surveillance activities. The present study uses a combination of geostatistical and mathematical modelling to predict the prevalence and transmission intensity of LF prior to the implementation of large-scale control in sub-Saharan Africa. Methods A systematic search of the literature was undertaken to identify surveys on the prevalence of Wuchereria bancrofti microfilaraemia (mf), based on blood smears, and on the prevalence of antigenaemia, based on the use of an immuno-chromatographic card test (ICT). Using a suite of environmental and demographic data, spatiotemporal multivariate models were fitted separately for mf prevalence and ICT-based prevalence within a Bayesian framework and used to make predictions for non-sampled areas. Maps of the dominant vector species of LF were also developed. The maps of predicted prevalence and vector distribution were linked to mathematical models of the transmission dynamics of LF to infer the intensity of transmission, quantified by the basic reproductive number (R0). Results The literature search identified 1267 surveys that provide suitable data on the prevalence of mf and 2817 surveys that report the prevalence of antigenaemia. Distinct spatial predictions arose from the models for mf prevalence and ICT-based prevalence, with a wider geographical distribution when using ICT-based data. The vector distribution maps demonstrated the spatial variation of LF vector species. Mathematical modelling showed that the reproduction number (R0) estimates vary from 2.7 to 30, with large variations between and within regions. Conclusions LF transmission is highly heterogeneous, and the developed maps can help guide intervention, monitoring and surveillance strategies as countries progress towards LF elimination.
- Published
- 2015
- Full Text
- View/download PDF
11. Epidemiology of coinfection with soil transmitted helminths and Plasmodium falciparum among school children in Bumula District in western Kenya
- Author
-
Stella Kepha, Fred Nuwaha, Birgit Nikolay, Paul Gichuki, Tansy Edwards, Elizabeth Allen, Sammy M. Njenga, Charles S. Mwandawiro, and Simon J Brooker
- Subjects
Soil transmitted helminths ,Hookworm ,Ascaris lumbricoides ,Plasmodium falciparum ,Coinfection ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Many school children living in Africa are infected with plasmodia and helminth species and are consequently at risk of coinfection. However, the epidemiology of such coinfection and the implications of coinfection for children’s health remain poorly understood. This study describes the epidemiology of Ascaris lumbricoides-Plasmodium and hookworm-Plasmodium coinfection among school children living in western Kenya and investigates the associated risk factors. Methods As part of a randomized trial, a baseline cross-sectional survey was conducted among school children aged 5–18 years in 23 schools in Bumula District. Single stool samples were collected to screen for helminth infections using the Kato-Katz technique and malaria parasitaemia was determined from a finger prick blood sample. Demographic and anthropometric data were also collected. Results Overall, 46.4 % of the children were infected with Plasmodium falciparum while 27.6 % of the children were infected with at least one soil transmitted helminth (STH) species, with hookworm being the most common (16.8 %) followed by A. lumbricoides (15.3 %). Overall 14.3 % of the children had STH-Plasmodium coinfection, with hookworm-Plasmodium (9.0 %) coinfection being the most common. Geographical variation in the prevalence of coinfection occurred between schools. In multivariable logistic regression analysis, hookworm was positively associated with P. falciparum infection. In stratified analysis, hookworm infection was associated with increased odds of P. falciparum infection among both boys (P
- Published
- 2015
- Full Text
- View/download PDF
12. Socioeconomic and environmental determinants of dengue transmission in an urban setting: An ecological study in Nouméa, New Caledonia.
- Author
-
Raphaël M Zellweger, Jorge Cano, Morgan Mangeas, François Taglioni, Alizé Mercier, Marc Despinoy, Christophe E Menkès, Myrielle Dupont-Rouzeyrol, Birgit Nikolay, and Magali Teurlai
- Subjects
Arctic medicine. Tropical medicine ,RC955-962 ,Public aspects of medicine ,RA1-1270 - Abstract
BACKGROUND:Dengue is a mosquito-borne virus that causes extensive morbidity and economic loss in many tropical and subtropical regions of the world. Often present in cities, dengue virus is rapidly spreading due to urbanization, climate change and increased human movements. Dengue cases are often heterogeneously distributed throughout cities, suggesting that small-scale determinants influence dengue urban transmission. A better understanding of these determinants is crucial to efficiently target prevention measures such as vector control and education. The aim of this study was to determine which socioeconomic and environmental determinants were associated with dengue incidence in an urban setting in the Pacific. METHODOLOGY:An ecological study was performed using data summarized by neighborhood (i.e. the neighborhood is the unit of analysis) from two dengue epidemics (2008-2009 and 2012-2013) in the city of Nouméa, the capital of New Caledonia. Spatial patterns and hotspots of dengue transmission were assessed using global and local Moran's I statistics. Multivariable negative binomial regression models were used to investigate the association between dengue incidence and various socioeconomic and environmental factors throughout the city. PRINCIPAL FINDINGS:The 2008-2009 epidemic was spatially structured, with clusters of high and low incidence neighborhoods. In 2012-2013, dengue incidence rates were more homogeneous throughout the city. In all models tested, higher dengue incidence rates were consistently associated with lower socioeconomic status (higher unemployment, lower revenue or higher percentage of population born in the Pacific, which are interrelated). A higher percentage of apartments was associated with lower dengue incidence rates during both epidemics in all models but one. A link between vegetation coverage and dengue incidence rates was also detected, but the link varied depending on the model used. CONCLUSIONS:This study demonstrates a robust spatial association between dengue incidence rates and socioeconomic status across the different neighborhoods of the city of Nouméa. Our findings provide useful information to guide policy and help target dengue prevention efforts where they are needed most.
- Published
- 2017
- Full Text
- View/download PDF
13. Evaluating Hospital-Based Surveillance for Outbreak Detection in Bangladesh: Analysis of Healthcare Utilization Data.
- Author
-
Birgit Nikolay, Henrik Salje, Katharine Sturm-Ramirez, Eduardo Azziz-Baumgartner, Nusrat Homaira, Makhdum Ahmed, A Danielle Iuliano, Repon C Paul, Mahmudur Rahman, M Jahangir Hossain, Stephen P Luby, Simon Cauchemez, and Emily S Gurley
- Subjects
Medicine - Abstract
BackgroundThe International Health Regulations outline core requirements to ensure the detection of public health threats of international concern. Assessing the capacity of surveillance systems to detect these threats is crucial for evaluating a country's ability to meet these requirements.Methods and findingsWe propose a framework to evaluate the sensitivity and representativeness of hospital-based surveillance and apply it to severe neurological infectious diseases and fatal respiratory infectious diseases in Bangladesh. We identified cases in selected communities within surveillance hospital catchment areas using key informant and house-to-house surveys and ascertained where cases had sought care. We estimated the probability of surveillance detecting different sized outbreaks by distance from the surveillance hospital and compared characteristics of cases identified in the community and cases attending surveillance hospitals. We estimated that surveillance detected 26% (95% CI 18%-33%) of severe neurological disease cases and 18% (95% CI 16%-21%) of fatal respiratory disease cases residing at 10 km distance from a surveillance hospital. Detection probabilities decreased markedly with distance. The probability of detecting small outbreaks (three cases) dropped below 50% at distances greater than 26 km for severe neurological disease and at distances greater than 7 km for fatal respiratory disease. Characteristics of cases attending surveillance hospitals were largely representative of all cases; however, neurological disease cases aged ConclusionWe present a new approach to evaluating the sensitivity and representativeness of hospital-based surveillance, making it possible to predict its ability to detect emerging threats.
- Published
- 2017
- Full Text
- View/download PDF
14. Understanding Heterogeneity in the Impact of National Neglected Tropical Disease Control Programmes: Evidence from School-Based Deworming in Kenya.
- Author
-
Birgit Nikolay, Charles S Mwandawiro, Jimmy H Kihara, Collins Okoyo, Jorge Cano, Mariam T Mwanje, Hadley Sultani, Dorcas Alusala, Hugo C Turner, Caroline Teti, Josh Garn, Matthew C Freeman, Elizabeth Allen, Roy M Anderson, Rachel L Pullan, Sammy M Njenga, and Simon J Brooker
- Subjects
Arctic medicine. Tropical medicine ,RC955-962 ,Public aspects of medicine ,RA1-1270 - Abstract
BACKGROUND:The implementation of soil-transmitted helminth (STH) treatment programmes occurs in varied environmental, social and economic contexts. Programme impact will be influenced by factors that affect the reduction in the prevalence and intensity of infections following treatment, as well as the subsequent rate of reinfection. To better understand the heterogeneity of programme impact and its underlying reasons, we investigated the influence of contextual factors on reduction in STH infection as part of the national school based deworming (SBD) programme in Kenya. MATERIALS AND METHODS:Data on the prevalence and intensity of infection were collected within the monitoring and evaluation component of the SBD programme at baseline and after delivery of two annual treatment rounds in 153 schools in western Kenya. Using a framework that considers STH epidemiology and transmission dynamics, capacity to deliver treatment, operational feasibility and financial capacity, data were assembled at both school and district (county) levels. Geographic heterogeneity of programme impact was assessed by descriptive and spatial analyses. Factors associated with absolute reductions of Ascaris lumbricoides and hookworm infection prevalence and intensity were identified using mixed effects linear regression modelling adjusting for baseline infection levels. PRINCIPAL FINDINGS:The reduction in prevalence and intensity of A. lumbricoides and hookworms varied significantly by county and within counties by school. Multivariable analysis of factors associated with programme impact showed that absolute A. lumbricoides reductions varied by environmental conditions and access to improved sanitation at schools or within the community. Larger reduction in prevalence and intensity of hookworms were found in schools located within areas with higher community level access to improved sanitation and within counties with higher economic and health service delivery indicator scores. CONCLUSIONS:The study identifies factors associated with the impact of school-based deworming and in particular highlights how access to water, sanitation and hygiene and environmental conditions influence the impact of deworming programmes.
- Published
- 2015
- Full Text
- View/download PDF
15. Integrating data and resources on neglected tropical diseases for better planning: the NTD mapping tool (NTDmap.org).
- Author
-
Rebecca M Flueckiger, Birgit Nikolay, Huub C Gelderblom, Jennifer L Smith, Danny Haddad, Wesley Tack, Guy Hendrickx, David Addiss, Jorge Cano, Danny R Hatcher, Adrian Hopkins, Rachel L Pullan, Alex Pavluck, Eric Ottesen, and Simon J Brooker
- Subjects
Arctic medicine. Tropical medicine ,RC955-962 ,Public aspects of medicine ,RA1-1270 - Published
- 2015
- Full Text
- View/download PDF
16. Seroprevalence of SARS-CoV-2 antibodies and retrospective mortality in two African settings: Lubumbashi, Democratic Republic of the Congo and Abidjan, Côte d’Ivoire
- Author
-
Erica Simons, Birgit Nikolay, Pascal Ouedraogo, Estelle Pasquier, Carlos Tiemeni, Ismael Adjaho, Colette Badjo, Kaouther Chamman, Mariam Diomandé, Mireille Dosso, Moussa Doumbia, Yves Asuni Izia, Hugues Kakompe, Anne Marie Katsomya, Vicky Kij, Viviane Kouakou Akissi, Christopher Mambula, Placide Mbala-Kingebeni, Jacques Muzinga, Basile Ngoy, Lou Penali, Alessandro Pini, Klaudia Porten, Halidou Salou, Daouda Sevede, Francisco Luquero, and Etienne Gignoux
- Abstract
BackgroundAlthough seroprevalence studies have demonstrated the wide circulation of SARS-COV-2 in African countries, the impact on population health in these settings is still poorly understood. Using representative samples of the general population, we evaluated retrospective mortality and seroprevalence of anti-SARS-CoV-2 antibodies in Lubumbashi and Abidjan.MethodsThe studies included retrospective mortality surveys and nested anti-SARS-CoV-2 antibody prevalence surveys. In Lubumbashi the study took place during April-May 2021 and in Abidjan the survey was implemented in two phases: July-August 2021 and October-November 2021. Crude mortality rates were stratified between pre-pandemic and pandemic periods and further investigated by age group and COVID waves. Anti-SARS-CoV-2 seroprevalence was quantified by rapid diagnostic testing (RDT) and laboratory-based testing (ELISA in Lubumbashi and ECLIA in Abidjan).ResultsIn Lubumbashi, the crude mortality rate (CMR) increased from 0.08 deaths per 10 000 persons per day (pre-pandemic) to 0.20 deaths per 10 000 persons per day (pandemic period). Increases were particularly pronounced among ConclusionAlthough circulation of SARS-CoV-2 seems to have been extensive in both settings, the public health impact varied. The increases, particularly among the youngest age group, suggest indirect impacts of COVID and the pandemic on population health. The seroprevalence results confirmed substantial underdetection of cases through the national surveillance systems.
- Published
- 2022
17. Transmission of Antimicrobial Resistant Yersinia pestis during a Pneumonic Plague Outbreak
- Author
-
Jason W. Sahl, Minoarisoa Rajerison, Nawarat Somprasong, Birgit Nikolay, Carina M. Hall, Harimahefa Razafimandimby, Christophe Rogier, Voahangy Andrianaivoarimanana, David M. Wagner, Amy J. Vogler, Lovasoa Nomena Randriantseheno, Herbert P. Schweizer, Simon Cauchemez, Faniry Rakotoarimanana, Dawn N. Birdsell, Institut Pasteur de Madagascar, Réseau International des Instituts Pasteur (RIIP), Northern Arizona University [Flagstaff], Modélisation mathématique des maladies infectieuses - Mathematical modelling of Infectious Diseases, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), University of Florida [Gainesville] (UF), Ministère de la Santé Publique - Ministry of Public Health [Antananarivo, Madagascar], and This work was supported by the Institut Pasteur de Madagascar
- Subjects
Microbiology (medical) ,Pneumonic plague ,Yersinia pestis ,[SDV]Life Sciences [q-bio] ,Virulence ,Bubonic plague ,Disease Outbreaks ,Antibiotic resistance ,medicine ,Animals ,antimicrobial resistance ,Retrospective Studies ,Plague ,biology ,outbreak ,Transmission (medicine) ,business.industry ,Outbreak ,biology.organism_classification ,medicine.disease ,Virology ,Anti-Bacterial Agents ,Infectious Diseases ,Streptomycin ,pneumonic plague ,business ,medicine.drug - Abstract
Background Pneumonic plague (PP), caused by Yersinia pestis, is the most feared clinical form of plague due to its rapid lethality and potential to cause outbreaks. PP outbreaks are now rare due to antimicrobial therapy. Methods A PP outbreak in Madagascar involving transmission of a Y. pestis strain resistant to streptomycin, the current recommended first-line treatment in Madagascar, was retrospectively characterized using epidemiology, clinical diagnostics, molecular characterization, and animal studies. Results The outbreak occurred in February 2013 in the Faratsiho district of Madagascar and involved 22 cases, including 3 untreated fatalities. The 19 other cases participated in funeral practices for the fatal cases and fully recovered after combination antimicrobial therapy: intramuscular streptomycin followed by oral co-trimoxazole. The Y. pestis strain that circulated during this outbreak is resistant to streptomycin resulting from a spontaneous point mutation in the 30S ribosomal protein S12 (rpsL) gene. This same mutation causes streptomycin resistance in 2 unrelated Y. pestis strains, one isolated from a fatal PP case in a different region of Madagascar in 1987 and another isolated from a fatal PP case in China in 1996, documenting this mutation has occurred independently at least 3 times in Y. pestis. Laboratory experiments revealed this mutation has no detectable impact on fitness or virulence, and revertants to wild-type are rare in other species containing it, suggesting Y. pestis strains containing it could persist in the environment. Conclusions Unique antimicrobial resistant (AMR) strains of Y. pestis continue to arise in Madagascar and can be transmitted during PP outbreaks.
- Published
- 2022
18. Specificity, kinetics and longevity of antibody responses to avian influenza A(H7N9) virus infection in humans
- Author
-
Peter Horby, Xiaowei Deng, Yi Guan, Hui Jiang, Hongjie Yu, Wei Wang, Jiaxin Zhou, Qianli Wang, Simon Cauchemez, Tianchen Zhang, Hongbo Zhu, Yongli Zhang, Timothy M. Uyeki, Xinhua Chen, Liwei Liu, Junbo Chen, Birgit Nikolay, Shanghai Medical College, Fundan University [Shanghai China], Shantou University [Shantou, China], The University of Hong Kong (HKU), University of Oxford, Capital University of Medical Sciences [Beijing] (CUMS), Beijing Tuberculosis and Thoracic Tumor Research Institute, Partenaires INRAE, Jiangxi Province People’s Hospital, University of Chinese Academy of Sciences [Beijing] (UCAS), Modélisation mathématique des maladies infectieuses - Mathematical modelling of Infectious Diseases, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Centers for Disease Control and Prevention [Atlanta] (CDC), Centers for Disease Control and Prevention, and ANR-10-LABX-0062,IBEID,Integrative Biology of Emerging Infectious Diseases(2010)
- Subjects
0301 basic medicine ,Microbiology (medical) ,animal structures ,[SDV]Life Sciences [q-bio] ,viruses ,030106 microbiology ,Disease ,medicine.disease_cause ,Antibodies, Viral ,Influenza A Virus, H7N9 Subtype ,Virus ,Article ,Serology ,03 medical and health sciences ,0302 clinical medicine ,Influenza, Human ,Medicine ,Animals ,Humans ,Clinical severity ,030212 general & internal medicine ,Influenza A(H7N9) ,Hemagglutination assay ,business.industry ,Follow-up ,Antibody titer ,virus diseases ,Influenza A virus subtype H5N1 ,Titer ,Kinetics ,Infectious Diseases ,Respiratory failure ,Influenza in Birds ,Immunology ,Antibody response ,Antibody Formation ,business ,Follow-Up Studies - Abstract
Highlights • A(H7N9) patients mounted strong serum HAI antibody responses against A(H7N9) virus. • Mean A(H7N9) virus-specific HAI antibody titers remained above 80 for 11 months. • Severely ill patients mounted higher HAI antibody responses against A(H7N9) virus., Objectives The long-term dynamics of antibody responses in patients with influenza A(H7N9) virus infection are not well understood. Methods We conducted a longitudinal serological follow-up study in patients who were hospitalized with A(H7N9) virus infection, during 2013–2018. A(H7N9) virus-specific antibody responses were assessed by hemagglutination inhibition (HAI) and neutralization (NT) assays. A random intercept model was used to fit a curve to HAI antibody responses over time. HAI antibody responses were compared by clinical severity. Results Of 67 patients with A(H7N9) virus infection, HAI antibody titers reached 40 on average 11 days after illness onset and peaked at a titer of 290 after three months, and average titers of ≥80 and ≥40 were present until 11 months and 22 months respectively. HAI antibody responses were significantly higher in patients who experienced severe disease, including respiratory failure and acute respiratory distress syndrome, compared with patients who experienced less severe illness. Conclusions Patients with A(H7N9) virus infection who survived severe disease mounted higher antibody responses that persisted for longer periods compared with those that experienced moderate disease. Studies of convalescent plasma treatment for A(H7N9) patients should consider collection of donor plasma from survivors of severe disease between 1 and 11 months after illness onset.
- Published
- 2020
19. Evaluating and optimizing the use of diagnostics during epidemics: Application to the 2017 plague outbreak in Madagascar
- Author
-
Quirine Bosch, Voahangy Andrianaivoarimanana, Beza Ramasindrazana, Guillain Mikaty, Rado JL Rakotonanahary, Birgit Nikolay, Soloandry Rahajandraibe, Maxence Feher, Quentin Grassin, Juliette Paireau, Soanandrasana Rahelinirina, Rindra Randremanana, Feno Rakotoarimanana, Marie Melocco, Voahangy Rasolofo, Javier Pizarro-Cerda, Anne-Sophie Le Guern, Eric Bertherat, Maherisoa Ratsitorahina, Andre Spiegel, Laurence Baril, Minoarisoa Rajerison, and Simon Cauchemez
- Abstract
During outbreaks, the lack of diagnostic “gold standard” can mask the true burden of infection in the population and hamper the allocation of resources required for control. Here, we present an analytical framework to evaluate and optimize the use of diagnostics when multiple yet imperfect diagnostic tests are available. We apply it to laboratory results of 2,136 samples, analyzed with three diagnostic tests (based on up to seven diagnostic outcomes), collected during the 2017 pneumonic (PP) and bubonic plague (BP) outbreak in Madagascar, which was unprecedented both in the number of notified cases, clinical presentation, and spatial distribution. The extent of this outbreaks has however remained unclear due to non-optimal assays. Using latent class methods, we estimate that 7%-15% of notified cases were Yersinia pestis-infected. Overreporting was highest during the peak of the outbreak and lowest in the rural settings endemic to Yersinia pestis. Molecular biology methods offered the best compromise between sensitivity and specificity. The specificity of the rapid diagnostic test was relatively low (PP: 82%, BP: 85%), particularly for use in contexts with large quantities of misclassified cases. Comparison with data from a subsequent seasonal Yersinia pestis outbreak in 2018 reveal better test performance (BP: specificity 99%, sensitivity: 91%), indicating that factors related to the response to a large, explosive outbreak may well have affected test performance. We used our framework to optimize the case classification and derive consolidated epidemic trends. Our approach may help reduce uncertainties in other outbreaks where diagnostics are imperfect.
- Published
- 2021
20. Assessing the feasibility of Nipah vaccine efficacy trials based on previous outbreaks in Bangladesh
- Author
-
Marc Lipsitch, Stephen P. Luby, Gabriel Ribeiro Dos Santos, Henrik Salje, Mahmudur Rahman, Emily S. Gurley, Birgit Nikolay, Simon Cauchemez, Modélisation mathématique des maladies infectieuses - Mathematical modelling of Infectious Diseases, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), University of Cambridge [UK] (CAM), Harvard T.H. Chan School of Public Health, Stanford University, Johns Hopkins Bloomberg School of Public Health [Baltimore], Johns Hopkins University (JHU), B. N. and S. C. acknowledge the support of the Laboratory of Excellence Integrative Biology of Emerging Infectious Diseases (Grant ANR-10-LABX-62-IBEID), the National Institute of General Medical Sciences Models of Infectious Disease Agent Study Initiative, the AXA Research Fund and the INCEPTION project (PIA/ANR-16-CONV-0005). B. N., E. G. and H. S. acknowledge the support of the Defense Advanced Research Projects Agency (Grant D18AC00031)., ANR-10-LABX-0062,IBEID,Integrative Biology of Emerging Infectious Diseases(2010), ANR-16-CONV-0005,INCEPTION,Institut Convergences pour l'étude de l'Emergence des Pathologies au Travers des Individus et des populatiONs(2016), and Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS)
- Subjects
medicine.medical_specialty ,030231 tropical medicine ,Context (language use) ,Nipah virus ,Disease cluster ,Disease Outbreaks ,03 medical and health sciences ,0302 clinical medicine ,[MATH.MATH-ST]Mathematics [math]/Statistics [math.ST] ,Epidemiology ,medicine ,Animals ,Humans ,030212 general & internal medicine ,030304 developmental biology ,0303 health sciences ,Bangladesh ,Vaccines ,General Veterinary ,General Immunology and Microbiology ,business.industry ,vaccine trial ,Clinical study design ,Public Health, Environmental and Occupational Health ,Vaccine trial ,Vaccine efficacy ,3. Good health ,Vaccination ,Infectious Diseases ,Case-Control Studies ,Emergency medicine ,Molecular Medicine ,Feasibility Studies ,Observational study ,Emerging pathogens ,business - Abstract
BackgroundNipah virus (NiV) is an emerging, bat-borne pathogen that can be transmitted from person-to-person. Vaccines are currently being developed for NiV, and studies funded to evaluate their safety and immunogenicity, so that they could possibly be used to contain outbreaks. An important unanswered question is whether it will be possible to evaluate the efficacy of vaccine candidates in phase III clinical trials in a context where spillovers from the zoonotic reservoir are infrequent and associated with small outbreaks. The objective of this study was to investigate the feasibility of conducting a phase III vaccine trial in Bangladesh, the only country reporting regularly NiV cases.MethodsWe used simulations based on previously observed NiV cases from Bangladesh, an assumed vaccine efficacy of 90% and other NiV vaccine target characteristics, to compare three vaccination study designs: (i) cluster randomized ring vaccination, (ii) cluster randomized mass vaccination, and (iii) an observational case-control study design.ResultsThe simulations showed that, assuming a ramp-up period of 10 days and a mean hospitalization delay of 4 days, it would take 516 years and over 163,000 vaccine doses to run a ring vaccination trial under current epidemic conditions. A cluster-randomized trial in the two most affected districts would take 81 years and 2.3 million vaccine doses. An observational case-control design in these two districts would require seven years and 2.5 million vaccine doses.DiscussionWithout a change in the epidemiology of NiV, ring vaccination or cluster-randomized trials are unlikely to be completed within a reasonable time window. In this light, the remaining options are: (i) not conducting a phase III trial until the epidemiology of NiV changes, (ii) identifying alternative ways to licensure such as observational studies or controlled studies in animals such as in the US Food and Drug Administration’s (FDA) Animal Rule.
- Published
- 2021
21. Seroprevalence and risk factors of exposure to COVID-19 in homeless people in Paris, France: a cross-sectional study
- Author
-
William Hennequin, Charline Vincent, Corinne Torre, Birgit Nikolay, Sophie Goyard, Bastien Mollo, Clair Mills, Jessica Vanhomwegen, Erica Simons, Emilie Fourrey, François Anna, Thierry Rose, Thomas Roederer, Robin Nesbitt, Francisco J. Luquero, Augusto E. Llosa, and Epicentre [Paris] [Médecins Sans Frontières]
- Subjects
medicine.medical_specialty ,Coronavirus disease 2019 (COVID-19) ,Cross-sectional study ,[SDV]Life Sciences [q-bio] ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,01 natural sciences ,03 medical and health sciences ,0302 clinical medicine ,Environmental health ,Food distribution ,Neutralization test ,Epidemiology ,Medicine ,Seroprevalence ,030212 general & internal medicine ,0101 mathematics ,ComputingMilieux_MISCELLANEOUS ,business.industry ,lcsh:Public aspects of medicine ,Public health ,010102 general mathematics ,1. No poverty ,Public Health, Environmental and Occupational Health ,lcsh:RA1-1270 ,Articles ,3. Good health ,business - Abstract
Summary: Background: During the COVID-19 lockdown period from March 17 to May 11, 2020, French authorities in Paris and its suburbs relocated people experiencing recurrent homelessness to emergency shelters, hotels, and large venues. A serological survey was done at some of these locations to assess the COVID-19 exposure prevalence in this group. Methods: We did a cross-sectional seroprevalence study at food distribution sites, emergency shelters, and workers' residences that were provided medical services by Médecins Sans Frontières in Paris and Seine-Saint-Denis in the Ile-de-France region. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody seropositivity was detected by Luciferase-Linked Immunosorbent Assay and Pseudo Neutralization Test. Sociodemographic and exposure related information was collected via a verbal questionnaire to analyse risk factors and associations with various COVID-19 symptoms. Findings: Between June 23 and July 2, 2020, 426 (52%) of 818 individuals recruited tested positive in 14 sites. Seroprevalence varied significantly by type of recruitment site (χ2 p
- Published
- 2021
22. Performance and operational feasibility of antigen and antibody rapid diagnostic tests for COVID-19 in symptomatic and asymptomatic patients in Cameroon: a clinical, prospective, diagnostic accuracy study
- Author
-
Nadia Mandeng, Nicole Fouda Mbarga, Bertrand Tchualeu Kameni, Tchoula Mamiafo Corine, Lucrèce Eteki, Okomo Marie Claire, Georges Alain Etoundi Mballa, Karl Njuwa Fai, Jean Patrick Ouamba, Aristide Abbah, Richard Njouom, Mark Ndifon, Linda Esso, Anne-Cécile Zoung-Kani Bisseck, Sara Eyangoh, Lisa M. Bebell, Bongkiyung Donald Buri, Mahamat Fanne, Emilienne Epée, Clement B. Ndongmo, Birgit Nikolay, Rene Ghislain Essomba, Modeste Tamakloé Koku, Achta Hamadou, Yap Boum, Rachel Essaka, Akenji Blaise Mboringong, Céline Langendorf, and Francisco J. Luquero
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Coronavirus disease 2019 (COVID-19) ,030106 microbiology ,Diagnostic accuracy ,Asymptomatic ,Sensitivity and Specificity ,03 medical and health sciences ,0302 clinical medicine ,Antigen ,Internal medicine ,medicine ,Humans ,030212 general & internal medicine ,Prospective cohort study ,Antigens, Viral ,Rapid diagnostic test ,biology ,business.industry ,SARS-CoV-2 ,Diagnostic test ,COVID-19 ,Articles ,Infectious Diseases ,biology.protein ,medicine.symptom ,Antibody ,business - Abstract
Summary Background Real-time PCR is recommended to detect SARS-CoV-2 infection. However, PCR availability is restricted in most countries. Rapid diagnostic tests are considered acceptable alternatives, but data are lacking on their performance. We assessed the performance of four antibody-based rapid diagnostic tests and one antigen-based rapid diagnostic test for detecting SARS-CoV-2 infection in the community in Cameroon. Methods In this clinical, prospective, diagnostic accuracy study, we enrolled individuals aged at least 21 years who were either symptomatic and suspected of having COVID-19 or asymptomatic and presented for screening. We tested peripheral blood for SARS-CoV-2 antibodies using the Innovita (Biological Technology; Beijing, China), Wondfo (Guangzhou Wondfo Biotech; Guangzhou, China), SD Biosensor (SD Biosensor; Gyeonggi-do, South Korea), and Runkun tests (Runkun Pharmaceutical; Hunan, China), and nasopharyngeal swabs for SARS-CoV-2 antigen using the SD Biosensor test. Antigen rapid diagnostic tests were compared with Abbott PCR testing (Abbott; Abbott Park, IL, USA), and antibody rapid diagnostic tests were compared with Biomerieux immunoassays (Biomerieux; Marcy l'Etoile, France). We retrospectively tested two diagnostic algorithms that incorporated rapid diagnostic tests for symptomatic and asymptomatic patients using simulation modelling. Findings 1195 participants were enrolled in the study. 347 (29%) tested SARS-CoV-2 PCR-positive, 223 (19%) rapid diagnostic test antigen-positive, and 478 (40%) rapid diagnostic test antibody-positive. Antigen-based rapid diagnostic test sensitivity was 80·0% (95% CI 71·0–88·0) in the first 7 days after symptom onset, but antibody-based rapid diagnostic tests had only 26·8% sensitivity (18·3–36·8). Antibody rapid diagnostic test sensitivity increased to 76·4% (70·1–82·0) 14 days after symptom onset. Among asymptomatic participants, the sensitivity of antigen-based and antibody-based rapid diagnostic tests were 37·0% (27·0–48·0) and 50·7% (42·2–59·1), respectively. Cohen's κ showed substantial agreement between Wondfo antibody rapid diagnostic test and gold-standard ELISA (κ=0·76; sensitivity 0·98) and between Biosensor and ELISA (κ=0·60; sensitivity 0·94). Innovita (κ=0·47; sensitivity 0·93) and Runkun (κ=0·43; sensitivity 0·76) showed moderate agreement. An antigen-based retrospective algorithm applied to symptomatic patients showed 94·0% sensitivity and 91·0% specificity in the first 7 days after symptom onset. For asymptomatic participants, the algorithm showed a sensitivity of 34% (95% CI 23·0–44·0) and a specificity of 92·0% (88·0–96·0). Interpretation Rapid diagnostic tests had good overall sensitivity for diagnosing SARS-CoV-2 infection. Rapid diagnostic tests could be incorporated into efficient testing algorithms as an alternative to PCR to decrease diagnostic delays and onward viral transmission. Funding Medecins Sans Frontieres WACA and Medecins Sans Frontieres OCG. Translations For the French and Spanish translations of the abstract see Supplementary Materials section.
- Published
- 2021
23. High seroprevalence of SARS-CoV-2 antibodies among people living in precarious situations in Ile de France
- Author
-
Thomas Roederer, Bastien Mollo, Charline Vincent, Birgit Nikolay, Augusto Llosa, Robin Nesbitt, Jessica Vanhomwegen, Thierry Rose, François Anna, Corinne Torre, Emilie Fourrey, Erica Simons, Sophie Goyard, Yves Janin, Pierre Charneau, Oxana Vratskikh, Anneliese Coury, Stefan Vanel, Pierre Mendiharat, Klaudia Porten, William Hennequin, Clair Mills, Francisco Luquero, Epicentre [Paris] [Médecins Sans Frontières], Médecins Sans Frontières [Paris] (MSF), Environnement et Risques infectieux - Environment and Infectious Risks (ERI), Institut Pasteur [Paris] (IP), Biologie Cellulaire des Lymphocytes - Lymphocyte Cell Biology, Institut Pasteur [Paris] (IP)-Institut National de la Santé et de la Recherche Médicale (INSERM), Virologie Moléculaire et Vaccinologie / Molecular Virology and Vaccinology, Laboratoire commun Pasteur-TheraVectys, Institut Pasteur [Paris] (IP)-TheraVectys, Chimie et Biocatalyse, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Janin, Yves, Institut Pasteur [Paris], Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut Pasteur [Paris], Institut Pasteur [Paris]-TheraVectys, and Centre National de la Recherche Scientifique (CNRS)-Institut Pasteur [Paris]
- Subjects
0303 health sciences ,education.field_of_study ,Coronavirus disease 2019 (COVID-19) ,[CHIM.ORGA]Chemical Sciences/Organic chemistry ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Population ,High seroprevalence ,Logistic regression ,[CHIM.ORGA] Chemical Sciences/Organic chemistry ,3. Good health ,03 medical and health sciences ,0302 clinical medicine ,Geography ,Environmental health ,Food distribution ,Pandemic ,Seroprevalence ,030212 general & internal medicine ,education ,030304 developmental biology - Abstract
BackgroundA nationwide lockdown was implemented in France on 17 March 2020 to control the COVID-19 pandemic. People living in precarious conditions were relocated by the authorities to emergency shelters, hotels and large venues. Médecins sans Frontières (MSF) then intervened to provide medical care in several of these locations in Paris and in Seine-Saint-Denis, one of its suburbs, between March and June 2020. A seroprevalence survey was conducted to assess the level of exposure to COVID-19 among the population living in the sites. To our knowledge, this is the first assessment of the impact of the pandemic on populations living in insecure conditions in Europe.MethodsWe conducted a cross-sectional seroprevalence study in the food distribution sites, emergency shelters and workers residences supported by MSF in Paris and Seine-Saint-Denis, to determine the extent of COVID-19 exposure as determined by SARS-CoV2 antibody seropositivity. The detection of SARS-COV2 antibodies in serum was performed at the Institut Pasteur of Paris using two LuLISA (Luciferase-Linked Immunosorbent Assay) assays and a Pseudo Neutralization Test. A questionnaire covering sociodemographic characteristics, living conditions, adherence to sanitary recommendations and symptom manifestations was also completed. We describe here the seroprevalence site by site and identify the risk factors for seropositivity using a multivariable logistic regression model with site random effects. We also investigated associations between seropositivity and symptoms eventually reported.FindingsOverall, 426/818 individuals tested positive in the 14 sites investigated. Seroprevalence varied significantly with the type of site (chi2 pInterpretationThe results demonstrate rather high exposure to SARS-COV-2 with important variations between study sites. Living in crowded conditions was identified as the most important explanatory factor for differences in levels of exposure. This study describes the key factors which determine the risk of exposure and illustrates the importance of identifying populations at high risk of exposure in order to orient and adapt prevention and control strategies to their specific needs.
- Published
- 2020
24. Changing Contact Patterns Over Disease Progression: Nipah Virus as a Case Study
- Author
-
Hossain M.S. Sazzad, Stuart T. Nichol, Juliet R. C. Pulliam, A. Marm Kilpatrick, Stephen P. Luby, Kyu Han Lee, M Jahangir Hossain, Henrik Salje, Peter Daszak, Emily S. Gurley, Birgit Nikolay, Mahmudur Rahman, Syed M Satter, Sharmin Sultana, John D. Klena, Simon Cauchemez, A. K. M. Dawlat Khan, Sayma Afroj, Johns Hopkins Bloomberg School of Public Health [Baltimore], Johns Hopkins University (JHU), Modélisation mathématique des maladies infectieuses - Mathematical modelling of Infectious Diseases, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), University of New South Wales [Sydney] (UNSW), London School of Hygiene and Tropical Medicine [Fajara, Gambia], London School of Hygiene and Tropical Medicine (LSHTM), Institute of Epidemiology Disease Control and Research [Dhaka, Bangladesh] (IEDCR), Centers for Disease Control and Prevention [Atlanta] (CDC), Centers for Disease Control and Prevention, Stellenbosch University, University of California [Santa Cruz] (UC Santa Cruz), University of California (UC), EcoHealth Alliance [New York], and Stanford University
- Subjects
Adult ,Male ,0301 basic medicine ,Adolescent ,Nipah virus ,[SDV]Life Sciences [q-bio] ,Disease ,Nipah Virus Infection ,Young Adult ,Major Articles and Brief Reports ,03 medical and health sciences ,0302 clinical medicine ,Risk Factors ,Disease Transmission, Infectious ,Humans ,Immunology and Allergy ,Medicine ,030212 general & internal medicine ,Social Behavior ,Henipavirus Infections ,Bangladesh ,business.industry ,Transmission (medicine) ,Risk of infection ,Disease progression ,Course of illness ,Nipah Virus ,Middle Aged ,Body Fluids ,030104 developmental biology ,Infectious Diseases ,Immunology ,Disease Progression ,Female ,Contact Tracing ,business ,Disease transmission - Abstract
Contact patterns play a key role in disease transmission, and variation in contacts during the course of illness can influence transmission, particularly when accompanied by changes in host infectiousness. We used surveys among 1642 contacts of 94 Nipah virus case patients in Bangladesh to determine how contact patterns (physical and with bodily fluids) changed as disease progressed in severity. The number of contacts increased with severity and, for case patients who died, peaked on the day of death. Given transmission has only been observed among fatal cases of Nipah virus infection, our findings suggest that changes in contact patterns during illness contribute to risk of infection.
- Published
- 2020
25. A framework to monitor changes in transmission and epidemiology of emerging pathogens: Lessons from Nipah virus
- Author
-
Syed M Satter, Henrik Salje, Birgit Nikolay, Hossain M.S. Sazzad, Simon Cauchemez, Barbara Knust, Meerjady Sabrina Flora, Mahmudur Rahman, A. K. M. Dawlat Khan, Stephen P. Luby, Emily S. Gurley, Stephanie Doan, Modélisation mathématique des maladies infectieuses - Mathematical modelling of Infectious Diseases, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Centers for Disease Control and Prevention [Atlanta] (CDC), Centers for Disease Control and Prevention, Institute of Epidemiology Disease Control and Research [Dhaka, Bangladesh] (IEDCR), Stanford University, Johns Hopkins Bloomberg School of Public Health [Baltimore], Johns Hopkins University (JHU), This work was funded by an National Institutes of Health grant for Ecology and Evolution of Infectious Diseases (Grant Numer 2R01-TW005869) and the US Centers for Disease Control and Prevention to its research efforts. icddr,b is thankful to the Governments of Bangladesh, Canada, Sweden, and the United Kingdom for providing core/unrestricted support. B. N., H. S., and S. C. acknowledge the support from the Laboratory of Excellence Integrative Biology of Emerging Infectious Diseases (Grant ANR-10-LABX-62-IBEID), the National Institute of General Medical Sciences Models of Infectious Disease Agent Study Initiative, and the AXA Research Fund and the INCEPTION project (PIA/ANR-16-CONV-0005). This research was supported by the Defense Advanced Research Projects Agency DARPA PREEMPT # D18AC00031., ANR-10-LABX-0062,IBEID,Integrative Biology of Emerging Infectious Diseases(2010), ANR-16-CONV-0005,INCEPTION,Institut Convergences pour l'étude de l'Emergence des Pathologies au Travers des Individus et des populatiONs(2016), and Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Monitoring ,Nipah virus ,030106 microbiology ,MESH: Henipavirus Infections ,Supplement Articles ,Communicable Diseases, Emerging ,Models, Biological ,Epidemiological indicators ,03 medical and health sciences ,Human health ,Risk Factors ,MESH: Risk Factors ,[MATH.MATH-ST]Mathematics [math]/Statistics [math.ST] ,Zoonoses ,Environmental health ,Epidemiology ,Global health ,medicine ,Animals ,Cluster Analysis ,Humans ,Immunology and Allergy ,MESH: Animals ,MESH: Communicable Diseases, Emerging ,MESH: Nipah Virus ,Henipavirus Infections ,Bangladesh ,Surveillance ,MESH: Humans ,Transmission (medicine) ,business.industry ,Public health ,MESH: Models, Biological ,MESH: Cluster Analysis ,3. Good health ,Pathogenic organism ,030104 developmental biology ,Infectious Diseases ,Emerging pathogens ,business ,MESH: Bangladesh ,MESH: Zoonoses - Abstract
It is of uttermost importance that the global health community develops the surveillance capability to effectively monitor emerging zoonotic pathogens that constitute a major and evolving threat for human health. In this study, we propose a comprehensive framework to measure changes in (1) spillover risk, (2) interhuman transmission, and (3) morbidity/mortality associated with infections based on 6 epidemiological key indicators derived from routine surveillance. We demonstrate the indicators’ value for the retrospective or real-time assessment of changes in transmission and epidemiological characteristics using data collected through a long-standing, systematic, hospital-based surveillance system for Nipah virus in Bangladesh. We show that although interhuman transmission and morbidity/mortality indicators were stable, the number and geographic extent of spillovers varied significantly over time. This combination of systematic surveillance and active tracking of transmission and epidemiological indicators should be applied to other high-risk emerging pathogens to prevent public health emergencies.
- Published
- 2020
26. A quantitative comparison of West Nile virus incidence from 2013 to 2018 in Emilia-Romagna, Italy
- Author
-
Silvia Bellini, Ilaria Dorigatti, Roberto Rosà, Marco Tamba, Romeo Bellini, Paola Angelini, Francesco Defilippo, Mattia Calzolari, Andrea Pugliese, Deborah Torri, Giovanni Marini, Birgit Nikolay, Luca Bolzoni, Medical Research Council (MRC), and Wellcome Trust
- Subjects
RNA viruses ,0301 basic medicine ,Entomology ,Veterinary medicine ,RC955-962 ,Mosquito population ,Disease Vectors ,medicine.disease_cause ,Mosquitoes ,Geographical locations ,law.invention ,0302 clinical medicine ,law ,Arctic medicine. Tropical medicine ,Epidemiology ,Pathology and laboratory medicine ,11 Medical and Health Sciences ,education.field_of_study ,Incidence ,Incidence (epidemiology) ,Temperature ,Eukaryota ,Medical microbiology ,Spring ,Insects ,Europe ,Culex ,Infectious Diseases ,Transmission (mechanics) ,Italy ,Viruses ,Vertebrates ,Female ,Seasons ,Pathogens ,Public aspects of medicine ,RA1-1270 ,West Nile virus ,Research Article ,medicine.medical_specialty ,Arthropoda ,030231 tropical medicine ,Population ,Mosquito Vectors ,Biology ,Microbiology ,Birds ,03 medical and health sciences ,Tropical Medicine ,medicine ,Animals ,Humans ,European Union ,Settore VET/06 - PARASSITOLOGIA E MALATTIE PARASSITARIE DEGLI ANIMALI ,education ,Medicine and health sciences ,Biology and life sciences ,Flaviviruses ,Organisms ,Viral pathogens ,Public Health, Environmental and Occupational Health ,Insect Bites and Stings ,Models, Theoretical ,06 Biological Sciences ,Invertebrates ,Microbial pathogens ,Insect Vectors ,Northern italy ,Species Interactions ,030104 developmental biology ,Amniotes ,Earth Sciences ,People and places ,Zoology ,West Nile Fever - Abstract
Background West Nile virus (WNV) transmission was much greater in 2018 than in previous seasons in Europe. Focusing on Emilia-Romagna region (northern Italy), we analyzed detailed entomological and epidemiological data collected in 2013–2018 to quantitatively assess environmental drivers of transmission and explore hypotheses to better understand why the 2018 epidemiological season was substantially different than the previous seasons. In particular, in 2018 WNV was detected at least two weeks before the observed circulation in 2013–2017 and in a larger number of mosquito pools. Transmission resulted in 100 neuroinvasive human cases in the region, more than the total number of cases recorded between 2013 and 2017. Methodology We used temperature-driven mathematical models calibrated through a Bayesian approach to simulate mosquito population dynamics and WNV infection rates in the avian population. We then estimated the human transmission risk as the probability, for a person living in the study area, of being bitten by an infectious mosquito in a given week. Finally, we translated such risk into reported WNV human infections. Principal findings The estimated prevalence of WNV in the mosquito and avian populations were significantly higher in 2018 with respect to 2013–2017 seasons, especially in the eastern part of the region. Furthermore, peak avian prevalence was estimated to have occurred earlier, corresponding to a steeper decline towards the end of summer. The high mosquito prevalence resulted in a much greater predicted risk for human transmission in 2018, which was estimated to be up to eight times higher than previous seasons. We hypothesized, on the basis of our modelling results, that such greater WNV circulation might be partially explained by exceptionally high spring temperatures, which have likely helped to amplify WNV transmission at the beginning of the 2018 season., Author summary West Nile virus (WNV) is one of the most recent emerging mosquito-borne diseases in Europe and North America. While most human infections are asymptomatic, about 1% of them can result in severe neurological diseases which might be fatal. WNV transmission was unusually greater in 2018 than in previous years in many European countries, resulting in a large number of human infections. Focusing on Emilia-Romagna region (Italy), we developed an epidemiological model informed by entomological data; through that we found that exceptionally high spring temperatures might have contributed at amplifying WNV transmission at the beginning of the season, causing greater WNV prevalence in mosquito and avian populations during the summer, which resulted in a higher estimated risk for human transmission. Thus, weather anomalies at the beginning of the mosquito breeding season, which are likely to become more common under the projected scenarios of climate change, might act as an early warning signal for public health authorities, enabling them to design efficient surveillance and prevention strategies.
- Published
- 2019
27. Serologic response to SARS-CoV-2 in an African population
- Author
-
Solange Peppa, Nadia Mandeng, Birgit Nikolay, Akenji Blaise Mboringong, Aristide Stéphane Abah Abah, Modeste Tamakloé Koku, Karl Njuwa Fai, Nicole Fouda Mbarga, Robert F. J. Nsaibirni, Dora Tchiasso, Yap Boum, Mahamat Fanne, Georges Alain Etoundi Mballa, Emilienne Epée, Lisa M. Bebell, Rodrigue Ntone, E. B.P.Taa Nguimbis, Richard Njouom, Achta Hamadou, Fouda Crescence, Sarah Eyangoh, Rachel Essaka, Lucrèce Eteki, Tchoula Mamiafo Corine, Mark Ndifon, Marie Claire Okomo Assoumou, Rene Ghislain Essomba, Lucrece Matchim, Linda Esso, and Jean Patrick Ouamba
- Subjects
Multidisciplinary ,biology ,Transmission (medicine) ,business.industry ,Science ,Rapid diagnostic tests ,COVID-19 ,Context (language use) ,Disease ,Asymptomatic ,Article ,Serology ,Africa ,Pandemic ,Immunoglobulin ,medicine ,biology.protein ,Seroprevalence ,medicine.symptom ,Antibody ,business ,Demography - Abstract
Official case counts suggest Africa has not seen the expected burden of COVID-19 as predicted by international health agencies, and the proportion of asymptomatic patients, disease severity, and mortality burden differ significantly in Africa from what has been observed elsewhere. Testing for SARS-CoV-2 was extremely limited early in the pandemic and likely led to under-reporting of cases leaving important gaps in our understanding of transmission and disease characteristics in the African context. SARS-CoV-2 antibody prevalence and serologic response data could help quantify the burden of COVID-19 disease in Africa to address this knowledge gap and guide future outbreak response, adapted to the local context. However, such data are widely lacking in Africa. We conducted a cross-sectional seroprevalence survey among 1,192 individuals seeking COVID-19 screening and testing in central Cameroon using the Innovita antibody-based rapid diagnostic. Overall immunoglobulin prevalence was 32%, IgM prevalence was 20%, and IgG prevalence was 24%. IgM positivity gradually increased, peaking around symptom day 20. IgG positivity was similar, gradually increasing over the first 10 days of symptoms, then increasing rapidly to 30 days and beyond. These findings highlight the importance of diagnostic testing and asymptomatic SARS-CoV-2 transmission in Cameroon, which likely resulted in artificially low case counts. Rapid antibody tests are a useful diagnostic modality for seroprevalence surveys and infection diagnosis starting 5-7 days after symptom onset. These results represent the first step towards better understanding the SARS-CoV-2 immunological response in African populations.
- Published
- 2021
28. Comparative Analysis of Eleven Healthcare-Associated Outbreaks of Middle East Respiratory Syndrome Coronavirus (Mers-Cov) from 2015 to 2017
- Author
-
Sibylle Bernard-Stoecklin, Mamunur Rahman Malik, Abdullah M. Assiri, Birgit Nikolay, Maria D. Van Kerkhove, Hassan El Bushra, Moran Ki, Simon Cauchemez, Abdul Aziz Bin Saeed, Arnaud Fontanet, Peter Ben Embarek, Center for Global Health Research and Education - Centre pour la Recherche et la Formation en Santé Mondiale (CGH), Institut Pasteur [Paris]-Réseau International des Instituts Pasteur (RIIP), Modélisation mathématique des maladies infectieuses - Mathematical modelling of Infectious Diseases, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Ministry of Health [Riyadh], Organisation Mondiale de la Santé / World Health Organization Office (OMS / WHO), National Cancer Center Korea, Regional Office for the Eastern Mediterranean [Cairo] (EMRO), Epidémiologie des Maladies Emergentes - Emerging Diseases Epidemiology, Pasteur-Cnam Risques infectieux et émergents (PACRI), Institut Pasteur [Paris]-Conservatoire National des Arts et Métiers [CNAM] (CNAM)-Institut Pasteur [Paris]-Conservatoire National des Arts et Métiers [CNAM] (CNAM), Conservatoire National des Arts et Métiers [CNAM] (CNAM), B.N. and S.C. acknowledge financial support from the Investissement d’Avenir program, the Laboratoire d’Excellence Integrative Biology of Emerging Infectious Diseases program (Grant ANR-10-LABX-62-IBEID), the Models of Infectious Disease Agent Study of the National Institute of General Medical Sciences, the AXA Research Fund and the INCEPTION project (PIA/ANR-16-CONV-0005)., ANR-10-LABX-0062,IBEID,Integrative Biology of Emerging Infectious Diseases(2010), ANR-16-CONV-0005,INCEPTION,Institut Convergences pour l'étude de l'Emergence des Pathologies au Travers des Individus et des populatiONs(2016), Institut Pasteur [Paris] (IP)-Réseau International des Instituts Pasteur (RIIP), Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), WHO - Regional Office for the Eastern Mediterranean [Cairo, Egypt] (EMRO), Institut Pasteur [Paris] (IP)-Conservatoire National des Arts et Métiers [CNAM] (CNAM), HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-Institut Pasteur [Paris] (IP)-Conservatoire National des Arts et Métiers [CNAM] (CNAM), HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM), and HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)
- Subjects
0301 basic medicine ,Male ,Multivariate analysis ,MESH: Coronavirus Infections ,lcsh:Medicine ,MESH: Infectious Disease Transmission, Professional-to-Patient ,MESH: Comorbidity ,Comorbidity ,medicine.disease_cause ,Disease Outbreaks ,Infectious Disease Transmission, Professional-to-Patient ,0302 clinical medicine ,Healthcare associated ,MESH: Risk Factors ,[MATH.MATH-ST]Mathematics [math]/Statistics [math.ST] ,Health care ,Epidemiology ,MESH: Disease Outbreaks ,lcsh:Science ,MESH: Aged ,Cross Infection ,Multidisciplinary ,MESH: Middle Aged ,Transmission (medicine) ,Age Factors ,Middle Aged ,MESH: Hospitals ,Hospitals ,3. Good health ,Middle East Respiratory Syndrome Coronavirus ,Infectious diseases ,Female ,Coronavirus Infections ,MESH: History, 21st Century ,Adult ,MESH: Republic of Korea ,medicine.medical_specialty ,Infectious Disease Transmission, Patient-to-Professional ,Middle East respiratory syndrome coronavirus ,Health Personnel ,Saudi Arabia ,History, 21st Century ,World health ,Article ,03 medical and health sciences ,Environmental health ,MESH: Infectious Disease Transmission, Patient-to-Professional ,Republic of Korea ,medicine ,Humans ,Aged ,MESH: Age Factors ,MESH: Humans ,business.industry ,lcsh:R ,MESH: Middle East Respiratory Syndrome Coronavirus ,Outbreak ,MESH: Cross Infection ,MESH: Adult ,MESH: Male ,MESH: Saudi Arabia ,030104 developmental biology ,Risk factors ,MESH: Health Personnel ,lcsh:Q ,business ,MESH: Female ,030217 neurology & neurosurgery - Abstract
Since its emergence in 2012, 2,260 cases and 803 deaths due to Middle East respiratory syndrome coronavirus (MERS-CoV) have been reported to the World Health Organization. Most cases were due to transmission in healthcare settings, sometimes causing large outbreaks. We analyzed epidemiologic and clinical data of laboratory-confirmed MERS-CoV cases from eleven healthcare-associated outbreaks in the Kingdom of Saudi Arabia and the Republic of Korea between 2015–2017. We quantified key epidemiological differences between outbreaks. Twenty-five percent (n = 105/422) of MERS cases who acquired infection in a hospital setting were healthcare personnel. In multivariate analyses, age ≥65 (OR 4.8, 95%CI: 2.6–8.7) and the presence of underlying comorbidities (OR: 2.7, 95% CI: 1.3–5.7) were associated with increased mortality whereas working as healthcare personnel was protective (OR 0.07, 95% CI: 0.01–0.34). At the start of these outbreaks, the reproduction number ranged from 1.0 to 5.7; it dropped below 1 within 2 to 6 weeks. This study provides a comprehensive characterization of MERS HCA-outbreaks. Our results highlight heterogeneities in the epidemiological profile of healthcare-associated outbreaks. The limitations of our study stress the urgent need for standardized data collection for high-threat respiratory pathogens, such as MERS-CoV.
- Published
- 2019
29. Transmission of Nipah Virus - 14 Years of Investigations in Bangladesh
- Author
-
Ute Ströher, Birgit Nikolay, John D. Klena, Simon Cauchemez, Sharmin Sultana, Stephen P. Luby, Henrik Salje, A. Marm Kilpatrick, Emily S. Gurley, Sayma Afroj, Peter Daszak, Hossain M.S. Sazzad, Juliet R. C. Pulliam, M Jahangir Hossain, Mahmudur Rahman, A. K. M. Dawlat Khan, Stuart T. Nichol, Modélisation mathématique des maladies infectieuses - Mathematical modelling of Infectious Diseases, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Medical Research Council Unit The Gambia (MRC), International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), University of New South Wales [Sydney] (UNSW), Institute of Epidemiology Disease Control and Research [Dhaka, Bangladesh] (IEDCR), EcoHealth Alliance [New York], Centers for Disease Control and Prevention [Atlanta] (CDC), Centers for Disease Control and Prevention, Stellenbosch University, University of California [Santa Cruz] (UCSC), University of California, Auburn University (AU), Stanford University, Johns Hopkins Bloomberg School of Public Health [Baltimore], Johns Hopkins University (JHU), Supported by a grant (2R01-TW005869) from the National Institutes of Health, by the CDC, by support from the Laboratory of Excellence Integrative Biology of Emerging Infectious Diseases (to Drs. Nikolay and Cauchemez), by support from the National Institute of General Medical Sciences Models of Infectious Disease Agent Study Initiative (to Drs. Nikolay and Cauchemez), by support from the INCEPTION project (PIA/ANR-16-CONV-0005) (to Drs. Nikolay, Salje, and Cauchemez), by support from the AXA Research Fund (to Drs. Nikolay and Cauchemez), and by core or unrestricted support from the governments of Bangladesh, Canada, Sweden, and the United Kingdom., ANR-10-LABX-0062,IBEID,Integrative Biology of Emerging Infectious Diseases(2010), ANR-16-CONV-0005,INCEPTION,Institut Convergences pour l'étude de l'Emergence des Pathologies au Travers des Individus et des populatiONs(2016), Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), University of California [Santa Cruz] (UC Santa Cruz), and University of California (UC)
- Subjects
Male ,viruses ,Nipah virus ,[SDV]Life Sciences [q-bio] ,MESH: Henipavirus Infections ,030204 cardiovascular system & hematology ,MESH: Body Fluids ,0302 clinical medicine ,MESH: Risk Factors ,[MATH.MATH-ST]Mathematics [math]/Statistics [math.ST] ,Risk Factors ,MESH: Child ,Zoonoses ,Medicine ,MESH: Animals ,030212 general & internal medicine ,MESH: Nipah Virus ,Child ,Henipavirus Infections ,Bangladesh ,MESH: Middle Aged ,Transmission (medicine) ,Age Factors ,food and beverages ,General Medicine ,Middle Aged ,3. Good health ,Body Fluids ,MESH: Young Adult ,Female ,MESH: Bangladesh ,MESH: Zoonoses ,Disease transmission ,Adult ,Adolescent ,Virulence ,MESH: Disease Transmission, Infectious ,Article ,MESH: Contact Tracing ,03 medical and health sciences ,Young Adult ,Disease Transmission, Infectious ,Animals ,Humans ,Zoonotic pathogen ,MESH: Adolescent ,MESH: Age Factors ,MESH: Humans ,business.industry ,Nipah Virus ,Outbreak ,MESH: Adult ,Virology ,MESH: Male ,Contact Tracing ,business ,MESH: Female ,Contact tracing - Abstract
International audience; BackgroundNipah virus is a highly virulent zoonotic pathogen that can be transmitted between humans. Understanding the dynamics of person-to-person transmission is key to designing effective interventions.MethodsWe used data from all Nipah virus cases identified during outbreak investigations in Bangladesh from April 2001 through April 2014 to investigate case-patient characteristics associated with onward transmission and factors associated with the risk of infection among patient contacts.ResultsOf 248 Nipah virus cases identified, 82 were caused by person-to-person transmission, corresponding to a reproduction number (i.e., the average number of secondary cases per case patient) of 0.33 (95% confidence interval [CI], 0.19 to 0.59). The predicted reproduction number increased with the case patient’s age and was highest among patients 45 years of age or older who had difficulty breathing (1.1; 95% CI, 0.4 to 3.2). Case patients who did not have difficulty breathing infected 0.05 times as many contacts (95% CI, 0.01 to 0.3) as other case patients did. Serologic testing of 1863 asymptomatic contacts revealed no infections. Spouses of case patients were more often infected (8 of 56 [14%]) than other close family members (7 of 547 [1.3%]) or other contacts (18 of 1996 [0.9%]). The risk of infection increased with increased duration of exposure of the contacts (adjusted odds ratio for exposure of >48 hours vs. ≤1 hour, 13; 95% CI, 2.6 to 62) and with exposure to body fluids (adjusted odds ratio, 4.3; 95% CI, 1.6 to 11).ConclusionsIncreasing age and respiratory symptoms were indicators of infectivity of Nipah virus. Interventions to control person-to-person transmission should aim to reduce exposure to body fluids. (Funded by the National Institutes of Health and others.)
- Published
- 2019
30. Epidemiological characteristics of an urban plague epidemic in Madagascar, August–November, 2017: an outbreak report
- Author
-
Beza Ramasindrazana, Rindra Randremanana, André Spiegel, Vaoary Razafimbia, Maherisoa Ratsitorahina, Lamina Arthur Rakotonjanabelo, Mamy Jean de Dieu Randria, Jean Marius Rakotondramanga, Simon Cauchemez, Eric Bertherat, Mihaja Raberahona, Minoarisoa Rajerison, Birgit Nikolay, Feno Manitra Jacob Rakotoarimanana, Soanandrasana Rahelinirina, Laurence Baril, Anne Sophie Le Guern, Charlotte Faty Ndiaye, Quirine A. ten Bosch, Fanjasoa Rakotomanana, Guillain Mikaty, Juliette Paireau, Soloandry Rahajandraibe, Lea Randriamampionona, Voahangy Rasolofo, Voahangy Andrianaivoarimanana, Unité d'Epidémiologie [Antananarivo, Madagascar] (IPM), Institut Pasteur de Madagascar, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP), Unité Peste - Plague Unit [Antananarivo, Madagascar], Modélisation mathématique des maladies infectieuses - Mathematical modelling of Infectious Diseases, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Ministère de la Santé Publique [Antananarivo, Madagascar], Hôpital Joseph Raseta Befelatanana, CHU d’Antananarivo, Cellule d'Intervention Biologique d'Urgence - Laboratory for Urgent Response to Biological Threats (CIBU), Institut Pasteur [Paris], Environnement et Risques infectieux - Environment and Infectious Risks (ERI), Yersinia, Organisation Mondiale de la Santé - World Health Organization [Madagascar] (OMS/WHO), Organisation Mondiale de la Santé / World Health Organization Office (OMS / WHO), Réseau International des Instituts Pasteur (RIIP), World Health Organisation (WHO), US Agency for International Development, WHO, Institut Pasteur, US Department of Health and Human Services, Laboratoire d'Excellence Integrative Biology of Emerging Infectious Diseases, Models of Infectious Disease Agent Study of the National Institute of General Medical Sciences, AXA Research Fund, and the INCEPTION programme., Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Ministère de la Santé Publique - Ministry of Public Health [Antananarivo, Madagascar], and Institut Pasteur [Paris] (IP)
- Subjects
Pneumonic plague ,Adult ,Male ,medicine.medical_specialty ,Adolescent ,Yersinia pestis ,[SDV]Life Sciences [q-bio] ,030231 tropical medicine ,Prevalence ,Bubonic plague ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Environmental health ,11. Sustainability ,Epidemiology ,medicine ,Madagascar ,Urban plague ,Humans ,Life Science ,030212 general & internal medicine ,Cities ,Child ,Epidemics ,Rapid diagnostic test ,Plague ,Incidence ,Infant, Newborn ,Outbreak ,Infant ,Middle Aged ,medicine.disease ,3. Good health ,Infectious Diseases ,Geography ,Infectious disease (medical specialty) ,Child, Preschool ,Female - Abstract
Background: Madagascar accounts for 75% of global plague cases reported to WHO, with an annual incidence of 200–700 suspected cases (mainly bubonic plague). In 2017, a pneumonic plague epidemic of unusual size occurred. The extent of this epidemic provides a unique opportunity to better understand the epidemiology of pneumonic plagues, particularly in urban settings. Methods: Clinically suspected plague cases were notified to the Central Laboratory for Plague at Institut Pasteur de Madagascar (Antananarivo, Madagascar), where biological samples were tested. Based on cases recorded between Aug 1, and Nov 26, 2017, we assessed the epidemiological characteristics of this epidemic. Cases were classified as suspected, probable, or confirmed based on the results of three types of diagnostic tests (rapid diagnostic test, molecular methods, and culture) according to 2006 WHO recommendations. Findings: 2414 clinically suspected plague cases were reported, including 1878 (78%) pneumonic plague cases, 395 (16%) bubonic plague cases, one (
- Published
- 2019
31. How Modelling Can Enhance the Analysis of Imperfect Epidemic Data
- Author
-
Simon Cauchemez, Nathanaël Hozé, Birgit Nikolay, Quirine A. ten Bosch, Anthony Cousien, Modélisation mathématique des maladies infectieuses - Mathematical modelling of Infectious Diseases, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), We acknowledge financial support from the AXA Research Fund, the Investissement d’Avenir program, the Laboratoire d’Excellence Integrative Biology of Emerging Infectious Diseases program (Grant ANR-10-LABX-62-IBEID), the Inception program and the Models of Infectious Disease Agent Study of the National Institute of General Medical Sciences., ANR-10-LABX-0062,IBEID,Integrative Biology of Emerging Infectious Diseases(2010), ANR-16-CONV-0005,INCEPTION,Institut Convergences pour l'étude de l'Emergence des Pathologies au Travers des Individus et des populatiONs(2016), and Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
0301 basic medicine ,epidemic dynamics ,Process (engineering) ,Computer science ,030231 tropical medicine ,Epidemic dynamics ,severity ,Article ,03 medical and health sciences ,0302 clinical medicine ,[MATH.MATH-ST]Mathematics [math]/Statistics [math.ST] ,Parasitic Diseases ,Animals ,Humans ,mathematical modelling ,[MATH]Mathematics [math] ,Mathematical model ,transmission ,risk assessment ,Models, Theoretical ,3. Good health ,030104 developmental biology ,Infectious Diseases ,Risk analysis (engineering) ,statistics ,Data Interpretation, Statistical ,Parasitology ,Imperfect ,Risk assessment ,Epidemiologic Methods - Abstract
Mathematical models play an increasingly important role in our understanding of the transmission and control of infectious diseases. Here, we present concrete examples illustrating how mathematical models, paired with rigorous statistical methods, are used to parse data of different levels of detail and breadth and estimate key epidemiological parameters (e.g., transmission and its determinants, severity, impact of interventions, drivers of epidemic dynamics) even when these parameters are not directly measurable, when data are limited, and when the epidemic process is only partially observed. Finally, we assess the hurdles to be taken to increase availability and applicability of these approaches in an effort to ultimately enhance their public health impact., Highlights Many data can be used to estimate the transmission potential of a pathogen, including descriptions of the transmission chains, human cluster sizes, sources of infection, and epidemic curves. An important agenda in public health is understanding the impact of control methods. However, the dynamic nature of epidemics makes this task challenging. Models can disentangle the natural course of outbreaks from the effect of external factors. In the absence of reliable surveillance data, models can reconstruct epidemic history by combining age-specific seroprevalence data with an understanding of the natural history of infection. Mechanisms of immunity are hard to observe at an individual level, yet they affect population-level dynamics. Models can tease out such signatures. Morbidity and mortality can be difficult to estimate when many infections are unobserved and severe infections are reported more often. Models can be used to correct for under-reporting and selection bias.
- Published
- 2019
32. Ascaris lumbricoides Infection Following School-Based Deworming in Western Kenya: Assessing the Role of Pupils' School and Home Water, Sanitation, and Hygiene Exposures
- Author
-
Birgit Nikolay, Collins Okoyo, Charles Mwandawiro, Carolyn Drews-Botsch, Simon Brooker, Elses Simiyu, Matthew C. Freeman, Joshua V. Garn, and Jimmy H. Kihara
- Subjects
Male ,Veterinary medicine ,Sanitation ,Improved water source ,media_common.quotation_subject ,030231 tropical medicine ,Helminthiasis ,Deworming ,03 medical and health sciences ,0302 clinical medicine ,Water Supply ,Hygiene ,Virology ,Environmental health ,Ascariasis ,medicine ,Animals ,Humans ,030212 general & internal medicine ,Ascaris lumbricoides ,Child ,media_common ,Anthelmintics ,Family Characteristics ,Schools ,biology ,business.industry ,Ascaris ,Articles ,medicine.disease ,biology.organism_classification ,Kenya ,Infectious Diseases ,Female ,Parasitology ,business - Abstract
Water, sanitation, and hygiene (WaSH) technologies and behaviors can prevent infection by soil-transmitted helminth species independently, but may also interact in complex ways. However, these interactions are poorly understood. The purpose of this study was to characterize how school and home WaSH exposures were associated with Ascaris lumbricoides infection and to identify relevant interactions between separate WaSH technologies and behaviors. A study was conducted among 4,404 children attending 51 primary schools in western Kenya. We used multivariable mixed effects logistic regression to characterize how various WaSH exposures were associated with A. lumbricoides infection after annual school-based deworming. Few WaSH behaviors and technologies were independently associated with A. lumbricoides infection. However, by considering relevant interdependencies between variables, important associations were elucidated. The association between handwashing and A. lumbricoides depended largely upon the pupils' access to an improved water source. Among pupils who had access to improved water sources, A. lumbricoides prevalence was lower for those who handwashed both at school and home compared with neither place (odds ratio: 0.38, 95% confidence interval: 0.18–0.83; P = 0.01). This study contributes to a further understanding of the impact of WaSH on A. lumbricoides infection and shows the importance of accounting for interactions between WaSH technologies and behaviors.
- Published
- 2016
33. Changes in the Transmission Dynamic of Chikungunya Virus in Southeastern Senegal
- Author
-
Scott C. Weaver, Oumar Ndiaye, Abdourahmane Sow, Mawlouth Diallo, Bakary Djilocalisse Sadio, Amadou A. Sall, Ousmane Faye, Anta Tall Dia, Birgit Nikolay, Oumar Faye, Denis Malvy, Jorge Cano, Simon Cauchemez, Arbovirus et Virus de Fièvres Hémorragiques [Dakar, Sénégal], Institut Pasteur de Dakar, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP), Université Cheikh Anta Diop [Dakar, Sénégal] (UCAD), Team MORPH3EUS (INSERM U1219 - UB - ISPED), Bordeaux population health (BPH), Université de Bordeaux (UB)-Institut de Santé Publique, d'Épidémiologie et de Développement (ISPED)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Bordeaux (UB)-Institut de Santé Publique, d'Épidémiologie et de Développement (ISPED)-Institut National de la Santé et de la Recherche Médicale (INSERM), Modélisation mathématique des maladies infectieuses, Centre National de la Recherche Scientifique (CNRS)-Institut Pasteur [Paris], Hub Bioinformatique et Biostatistique - Bioinformatics and Biostatistics HUB, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), London School of Hygiene and Tropical Medicine (LSHTM), Unité d'Entomologie Médicale [Dakar] (UEM), The University of Texas Medical Branch (UTMB), The research was supported by the National Institutes of Health (NIH), Grant Number AI1069145., Modélisation mathématique des maladies infectieuses - Mathematical modelling of Infectious Diseases, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), and Limouzin, Cécile
- Subjects
Male ,Rural Population ,0301 basic medicine ,Veterinary medicine ,lcsh:QR1-502 ,environmental risk ,MESH: Chikungunya Fever ,Forests ,Antibodies, Viral ,medicine.disease_cause ,Logistic regression ,spatial autocorrelation ,Population density ,lcsh:Microbiology ,law.invention ,MESH: Aged, 80 and over ,0302 clinical medicine ,MESH: Rural Population ,Seroepidemiologic Studies ,[MATH.MATH-ST]Mathematics [math]/Statistics [math.ST] ,law ,MESH: Child ,Chikungunya ,Child ,[MATH.MATH-ST] Mathematics [math]/Statistics [math.ST] ,Aged, 80 and over ,MESH: Aged ,MESH: Immunoglobulin G ,MESH: Middle Aged ,Age Factors ,virus diseases ,Middle Aged ,MESH: Forests ,MESH: Mining ,MESH: Infant ,Senegal ,3. Good health ,Infectious Diseases ,Transmission (mechanics) ,MESH: Young Adult ,Child, Preschool ,Female ,Sylvatic cycle ,Adult ,Adolescent ,MESH: Population Density ,030231 tropical medicine ,Environment ,Biology ,Article ,Mining ,gold mining ,Young Adult ,03 medical and health sciences ,MESH: Senegal ,Virology ,medicine ,Humans ,Seroprevalence ,MESH: Environment ,Aged ,Population Density ,MESH: Adolescent ,MESH: Age Factors ,MESH: Seroepidemiologic Studies ,MESH: Humans ,MESH: Child, Preschool ,Infant ,Outbreak ,MESH: Adult ,Odds ratio ,15. Life on land ,MESH: Male ,030104 developmental biology ,Immunoglobulin G ,Chikungunya Fever ,MESH: Female ,MESH: Antibodies, Viral - Abstract
In Senegal, chikungunya virus (CHIKV) is maintained in a sylvatic cycle and causes sporadic cases or small outbreaks in rural areas. However, little is known about the influence of the environment on its transmission. To address the question, 120 villages were randomly selected in the Kedougou region of southeastern Senegal. In each selected village, 10 persons by randomly selected household were sampled and tested for specific anti-CHIKV IgG antibodies by ELISA. We investigated the association of CHIKV seroprevalence with environmental variables using logistic regression analysis and the spatial correlation of village seroprevalence based on semivariogram analysis. Fifty-four percent (51%&ndash, 57%) of individuals sampled during the survey tested positive for CHIKV-specific IgG. CHIKV seroprevalence was significantly higher in populations living close to forested areas (Normalized Difference Vegetation Index (NDVI), Odds Ratio (OR) = 1.90 (1.42&ndash, 2.57)), and was negatively associated with population density (OR = 0.76 (0.69&ndash, 0.84)). In contrast, in gold mining sites where population density was >, 400 people per km2, seroprevalence peaked significantly among adults (46% (27%&ndash, 67%)) compared to all other individuals (20% (12%&ndash, 31%)). However, traditional gold mining activities significantly modify the transmission dynamic of CHIKV, leading to a potential increase of the risk of human exposition in the region.
- Published
- 2020
34. Genomic and epidemiological monitoring of yellow fever virus transmission potential
- Author
-
Marcos Cesar Lima de Mendonça, Maira Alves Pereira, Mariana Sequetin Cunha, Mariane Talon de Menezes, Ester Cerdeira Sabino, Deise Aparecida dos Santos, Giliane de Souza Trindade, Juliana Silva Nogueira, Felipe Campos de Melo Iani, Rodrigo Dias de Oliveira Carvalho, Guy Baele, Erna Geessien Kroon, Talita Émile Ribeiro Adelino, Alexandre Otavio Chieppe, Betânia Paiva Drumond, Simon Dellicour, Maria Angelica Mares Guia, Nuno R. Faria, Kuiama Lewandowski, Izabela Maurício de Rezende, Ludmila Ferraz de Santana, William Wint, Ricardo Gadelha de Abreu, Julien Thézé, André Luis de Abreu, Jaqueline Goes de Jesus, Tetyana I. Vasylyeva, Vagner Fonseca, Shirley Vasconcelos Komninakis, Marcos Vieira Silva, Carlos Frederico Campelo de Albuquerque, Renato S. Aguiar, Miles W. Carroll, Sarah C. Hill, Freya M Shearer, Paola P. Silveira, D. Yi, Moritz U. G. Kraemer, Luiz Carlos Junior Alcantara, Joshua Quick, Vasco Azevedo, L. du Plessis, Érica Munhoz de Mello, T. de Oliveira, Philippe Lemey, Carolina Cardoso dos Santos, Daniel J. Weiss, José Lourenço, Leandro Abade, Patrícia Carvalho de Sequeira, Oliver G. Pybus, Lívia Sacchetto, Rita Maria Ribeiro Nogueira, Osnei Okumoto, Rodrigo Fabiano do Carmo Said, Monica B. Arruda, Ana Maria Bispo de Filippis, Poliana de Oliveira Figueiredo, Uri Obolski, Iray Maria Rocco, Chieh-Hsi Wu, Eliane Saraiva Machado de Araújo, Rodrigo Brindeiro, Renato Pereira de Souza, Birgit Nikolay, Marta Giovanetti, Simon Cauchemez, Nicholas J. Loman, Mariana Gontijo de Brito, Sebastian Funk, Steven T. Pullan, Cintia Damasceno dos Santos Rodrigues, Joilson Xavier, Gavin Pereira, A. C. da Costa, Marcio Henrique de Oliveira Garcia, Amilcar Tanuri, Marc A. Suchard, Fabiana Cristina Pereira dos Santos, Marcela Lencine Ferraz, Marluce Aparecida Assunção Oliveira, University of Oxford, Laboratório de Biologia Molecular de Flavivírus [Rio de Janeiro], Instituto Oswaldo Cruz / Oswaldo Cruz Institute [Rio de Janeiro] (IOC), Fundação Oswaldo Cruz / Oswaldo Cruz Foundation (FIOCRUZ), Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP)-Fundação Oswaldo Cruz / Oswaldo Cruz Foundation (FIOCRUZ), Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP), Universidade Federal do Rio de Janeiro (UFRJ), Rega Institute for Medical Research [Leuven, België], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), London School of Hygiene and Tropical Medicine (LSHTM), Modélisation mathématique des maladies infectieuses - Mathematical modelling of Infectious Diseases, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Centre de Bioinformatique, Biostatistique et Biologie Intégrative (C3BI), Universidade Federal de Minas Gerais [Belo Horizonte] (UFMG), University of Oxford [Oxford], Fundação Oswaldo Cruz (FIOCRUZ), Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP)-Fundação Oswaldo Cruz (FIOCRUZ), and Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS)
- Subjects
0301 basic medicine ,Virus transmission ,Spatial expansion ,[SDV]Life Sciences [q-bio] ,Polymerase Chain Reaction ,law.invention ,Disease Outbreaks ,0302 clinical medicine ,law ,Aedes ,2.2 Factors relating to the physical environment ,Aetiology ,Phylogeny ,Multidisciplinary ,Yellow fever ,Age Factors ,Genomics ,Sciences bio-médicales et agricoles ,3. Good health ,Transmission (mechanics) ,Infectious Diseases ,Epidemiological Monitoring ,Yellow fever virus ,Early phase ,Infection ,Brazil ,Risk ,Evolution ,General Science & Technology ,030231 tropical medicine ,Biology ,Age and sex ,Vaccine Related ,Evolution, Molecular ,03 medical and health sciences ,Rare Diseases ,Sex Factors ,Spatio-Temporal Analysis ,Biodefense ,Yellow Fever ,medicine ,Genetics ,Animals ,Humans ,Prevention ,Molecular ,biology.organism_classification ,medicine.disease ,Virology ,030104 developmental biology ,Emerging Infectious Diseases ,BRASIL - Abstract
The yellow fever virus (YFV) epidemic in Brazil is the largest in decades. The recent discovery of YFV in Brazilian Aedes species mosquitos highlights a need to monitor the risk of reestablishment of urban YFV transmission in the Americas. We use a suite of epidemiological, spatial, and genomic approaches to characterize YFV transmission. We show that the age and sex distribution of human cases is characteristic of sylvatic transmission. Analysis of YFV cases combined with genomes generated locally reveals an early phase of sylvatic YFV transmission and spatial expansion toward previously YFV-free areas, followed by a rise in viral spillover to humans in late 2016. Our results establish a framework for monitoring YFV transmission in real time that will contribute to a global strategy to eliminate future YFV epidemics., info:eu-repo/semantics/published
- Published
- 2018
35. Dengue serosurvey after a 2-month long outbreak in Nîmes, France, 2015: was there more than met the eye?
- Author
-
Tiphanie Succo, Amandine Cochet, Birgit Nikolay, Marianne Maquart, Cyril Rousseau, Harold Noel, Simon Cauchemez, Henrik Salje, Olivier Catelinois, Perrine de Crouy-Chanel, Isabelle Leparc-Goffart, Camille Pelat, Henriette de Valk, Centre d'épidémiologie et de santé publique des armées (CESPA), Service de Santé des Armées, Santé publique France [Saint-Maurice, France] (French National Public Health Agency), parent-French National Public Health Agency, Institut de Veille Sanitaire (INVS), Modélisation mathématique des maladies infectieuses, Centre National de la Recherche Scientifique (CNRS)-Institut Pasteur [Paris], Unité des Virus Emergents (UVE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut de Recherche Biomédicale des Armées [Antenne Marseille] (IRBA), Centre National de Référence des Arbovirus [Marseille], Institut de Recherche Biomédicale des Armées [Antenne Marseille] (IRBA)-Unité d'Arbovirologie [Marseille], Hôpital d'Instruction des Armées Laveran, Service de Santé des Armées-Service de Santé des Armées-Hôpital d'Instruction des Armées Laveran, Service de Santé des Armées-Service de Santé des Armées, Centre de Bioinformatique, Biostatistique et Biologie Intégrative (C3BI), Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Epidémiologie des maladies infectieuses et modélisation (ESIM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM), Unité de Catalyse et de Chimie du Solide - Site Artois (UCCS Artois), Université d'Artois (UA)-Université de Lille, Sciences et Technologies-Ecole Centrale de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Centre National de la Recherche Scientifique (CNRS), Santé publique France - French National Public Health Agency [Saint-Maurice, France], Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Salje, Henrik [0000-0003-3626-4254], Apollo - University of Cambridge Repository, and BUISINE, Soline
- Subjects
Male ,Epidemiology ,viruses ,030231 tropical medicine ,Aedes aegypti ,Mosquito Vectors ,Dengue virus ,medicine.disease_cause ,Disease cluster ,Dengue fever ,Dengue outbreak – Seroprevalence – Transmission risk – Aedes albopictus – Europe/France – West Nile virus ,Disease Outbreaks ,Dengue ,03 medical and health sciences ,0302 clinical medicine ,Aedes ,Seroepidemiologic Studies ,[SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases ,Virology ,medicine ,Prevalence ,Seroprevalence ,Animals ,Humans ,030212 general & internal medicine ,Chikungunya ,[SDV.MP.VIR] Life Sciences [q-bio]/Microbiology and Parasitology/Virology ,[SDV.MHEP.ME] Life Sciences [q-bio]/Human health and pathology/Emerging diseases ,Spatial Analysis ,[SDV.MHEP.ME]Life Sciences [q-bio]/Human health and pathology/Emerging diseases ,biology ,Transmission (medicine) ,Public Health, Environmental and Occupational Health ,Outbreak ,virus diseases ,Dengue Virus ,medicine.disease ,biology.organism_classification ,3. Good health ,Geography ,[SDV.SPEE] Life Sciences [q-bio]/Santé publique et épidémiologie ,[SDV.MP.VIR]Life Sciences [q-bio]/Microbiology and Parasitology/Virology ,[SDV.MHEP.MI] Life Sciences [q-bio]/Human health and pathology/Infectious diseases ,Female ,[SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie ,France ,Demography ,Research Article - Abstract
Dengue is the most common vector-borne viral disease worldwide, affecting 390 million people in tropical and sub-tropical areas each year [1]. The clinical spectrum of dengue ranges from a mild, non-specific febrile syndrome (classic dengue fever) to severe dengue with plasma leakage, haemorrhage or organ impairment [2]. In 20–97% of cases, dengue is clinically inapparent; this proportion varies considerably, across countries and years [3]. Asymptomatic infections may contribute significantly to virus transmission [4]. Aedes aegypti is the main vector of dengue virus in tropical areas [5]. Of more direct concern to continental Europe is a secondary vector, Ae. albopictus. Originally a tree-breeding mosquito of the forests of south-east Asia, Ae. albopictus has dramatically expanded its geographic distribution throughout the world in the past 40 years. Taking advantage of increasing global trade, Ae. albopictus spread to temperate regions in the late 1970s [6]. It was first reported in Europe in 1979 and has since been observed in France and 14 other countries along the Mediterranean. Given the recent establishment and rapid spread of Ae. albopictus in southern France, there is high potential for the emergence of arboviruses such as dengue virus (DENV), chikungunya and Zika viruses [7-10]. Limited local transmission of DENV was reported in southern France in 2010, 2013 and 2014, each cluster involving ≤ 2 cases [11-13]. Recently, from July to September 2015, a dengue outbreak occurred in the neighbourhood of Nimes, Occitanie region [14]. Epidemiological investigations including door-to-door case finding conducted in August 2015 revealed seven autochthonous cases of dengue serotype 1 (DENV-1) that arose from a likely primary case over a 2-month period [14]. In France, a national surveillance and response plan aims to prevent and control local dissemination of dengue and other Ae. albopictus-transmitted viruses. However, little is known about the drivers and determinants of local transmission of dengue in the European setting, and the national response plan may not be fully effective. In November 2015 we carried out a seroprevalence survey in order to determine the true extent of the dengue outbreak in Nimes and the proportion of asymptomatic infections. We also reconstructed the transmission chain to characterise the spatial pattern of dengue transmission and to contribute to improving the performance of the French surveillance and response plan.
- Published
- 2018
36. A review of West Nile and Usutu virus co-circulation in Europe: how much do transmission cycles overlap?
- Author
-
Birgit Nikolay
- Subjects
Culex ,viruses ,Cross immunity ,Communicable Diseases, Emerging ,Virus ,Disease Outbreaks ,Flavivirus Infections ,Birds ,Prevalence ,medicine ,Animals ,Humans ,biology ,Bird Diseases ,Encephalitis, Arbovirus ,Public Health, Environmental and Occupational Health ,virus diseases ,General Medicine ,Japanese encephalitis ,medicine.disease ,biology.organism_classification ,Virology ,Europe ,Flavivirus ,Infectious Diseases ,Encephalitis Viruses, Japanese ,Vector (epidemiology) ,Parasitology ,Usutu virus ,West Nile Fever - Abstract
Due to the increasing global spread of arboviruses, the geographic extent of virus co-circulation is expanding. This complicates the diagnosis of febrile conditions and can have direct effects on the epidemiology. As previously demonstrated, subsequent infections by two closely related viruses, such as those belonging to the Japanese encephalitis virus (JEV) serocomplex, can lead to partial or complete cross-immunity, altering the risk of infections or the outcome of disease. Two flaviviruses that may interact at population level are West Nile virus (WNV) and Usutu virus (USUV). These pathogens have antigenic cross-reactivity and affect human and animal populations throughout Europe. This systematic review investigates the overlap of WNV and USUV transmission cycles, not only geographically but also in terms of host and vector ranges. Co-circulation of WNV and USUV was reported in 10 countries and the viruses were found to infect 34 common bird species belonging to 11 orders. Moreover, four mosquito species are potential vectors for both viruses. Taken together, these data suggest that WNV and USUV transmission overlaps substantially in Europe and highlight the importance of further studies investigating the interactions between the two viruses within host and vector populations.
- Published
- 2015
37. Effect of Repeated Anthelminthic Treatment on Malaria in School Children in Kenya: A Randomized, Open-Label, Equivalence Trial
- Author
-
Pauline N. M. Mwinzi, Paul M. Gichuki, Birgit Nikolay, Stella Kepha, Simon Brooker, Charles Mwandawiro, Maurice R. Odiere, Elizabeth Allen, Tansy Edwards, and Fred Nuwaha
- Subjects
Male ,Pediatrics ,medicine.medical_specialty ,Adolescent ,030231 tropical medicine ,malaria ,Helminthiasis ,Parasitemia ,deworming ,Albendazole ,Drug Administration Schedule ,Deworming ,Major Articles and Brief Reports ,03 medical and health sciences ,0302 clinical medicine ,Risk Factors ,parasitic diseases ,medicine ,Humans ,Immunology and Allergy ,Parasites ,030212 general & internal medicine ,Malaria, Falciparum ,Child ,helminths ,Anthelmintics ,business.industry ,Incidence (epidemiology) ,school children ,medicine.disease ,Kenya ,Confidence interval ,3. Good health ,Clinical trial ,Infectious Diseases ,Equivalence Trial ,Immunology ,Female ,business ,Malaria - Abstract
Background. School children living in the tropics are often concurrently infected with plasmodium and helminth parasites. It has been hypothesized that immune responses evoked by helminths may modify malaria-specific immune responses and increase the risk of malaria. Methods. We performed a randomized, open-label, equivalence trial among 2436 school children in western Kenya. Eligible children were randomized to receive either 4 repeated doses or a single dose of albendazole and were followed up during 13 months to assess the incidence of clinical malaria. Secondary outcomes were Plasmodium prevalence and density, assessed by repeat cross-sectional surveys over 15 months. Analysis was conducted on an intention-to-treat basis with a prespecified equivalence range of 20%. Results. During 13 months of follow-up, the incidence rate of malaria was 0.27 episodes/person-year in the repeated treatment group and 0.26 episodes/person-year in the annual treatment group (incidence difference, 0.01; 95% confidence interval, −.03 to .06). The prevalence and density of malaria parasitemia did not differ by treatment group at any of the cross-sectional surveys. Conclusions. Our findings suggest that repeated deworming does not alter risks of clinical malaria or malaria parasitemia among school children and that school-based deworming in Africa may have no adverse consequences for malaria. Clinical Trials Registration. {"type":"clinical-trial","attrs":{"text":"NCT01658774","term_id":"NCT01658774"}}NCT01658774.
- Published
- 2015
38. Impact of single annual treatment and four-monthly treatment for hookworm and Ascaris lumbricoides, and factors associated with residual infection among Kenyan school children
- Author
-
Maurice R. Odiere, Simon Brooker, Sammy M. Njenga, Stella Kepha, Jorge Cano, Elizabeth Allen, Birgit Nikolay, Rachel L. Pullan, Fred Nuwaha, Charles Mwandawiro, Roy M. Anderson, and Bill & Melinda Gates Foundation
- Subjects
Ancylostomatoidea ,Male ,PRESCHOOL-CHILDREN ,law.invention ,Deworming ,0302 clinical medicine ,Randomized controlled trial ,law ,School children ,EPIDEMIOLOGY ,Medicine ,Longitudinal Studies ,030212 general & internal medicine ,Child ,Anthelmintics ,Ascariasis ,Schools ,biology ,Soil-transmitted helminths ,ANTHELMINTIC TREATMENT ,General Medicine ,OPEN-LABEL ,3. Good health ,Treatment Outcome ,Infectious Diseases ,Child, Preschool ,Female ,Ascaris lumbricoides ,Life Sciences & Biomedicine ,Research Article ,medicine.drug ,INTESTINAL HELMINTHS ,medicine.medical_specialty ,Adolescent ,030231 tropical medicine ,Albendazole ,School-based deworming ,Hookworm Infections ,03 medical and health sciences ,Internal medicine ,TRANSMITTED HELMINTH INFECTIONS ,Animals ,Humans ,REINFECTION ,Students ,Hookworm infection ,METAANALYSIS ,Science & Technology ,business.industry ,HOUSEHOLD ,Public Health, Environmental and Occupational Health ,medicine.disease ,biology.organism_classification ,Kenya ,PREDISPOSITION ,Immunology ,Tropical medicine ,business ,Malaria - Abstract
Background School-based deworming is widely implemented in various countries to reduce the burden of soil-transmitted helminths (STHs), however, the frequency of drug administration varies in different settings. In this study, we compared the impact of a single annual treatment and 4-monthly treatment over a follow-up among Kenyan school children, and investigated the factors associated with residual infection. Methods We performed a secondary analysis of data from a randomized trial investigating whether deworming for STHs alters risk of acquiring malaria. Children received either a single treatment or 4-monthly albendazole treatments were followed longitudinally from February 2014 to October 2014. The relative impact of treatment and factors associated with residual infections were investigated using mixed-effects regression models. Predisposition to infection was assessed based on Spearman’s rank and Kendall’s Tau correlation coefficients. Results In the 4-monthly treatment group, the proportion of children infected with hookworm decreased from 59.9 to 5.7%, while Ascaris lumbricoides infections dropped from 55.7 to 6.2%. In the single treatment group, hookworm infections decreased over the same time period from 58.7 to 18.3% (12.6% absolute difference in reduction, 95% CI: 8.9–16.3%), and A. lumbricoides from 56.7 to 23.3% (17.1% absolute difference in reduction, 95% CI: 13.1–21.1%). There was strong evidence for predisposition to both STH types. Residual hookworm infection among children on 4-monthly treatment were associated with male sex and baseline nutritional status, whereas A. lumbricoides infection was associated with individual and school-level infection at baseline, latrine cleanliness at schools. Conclusions This study found that 4-monthly treatment w more effective than single annual treatment. Repeated treatments led to dramatic reductions in the intensities of STHs, but did not completely clear infections among school children in Kenya, a presumed reflection of reinfection in a setting where there is ongoing transmission. Electronic supplementary material The online version of this article (doi:10.1186/s40249-017-0244-z) contains supplementary material, which is available to authorized users.
- Published
- 2017
39. Evaluating Hospital-Based Surveillance for Outbreak Detection in Bangladesh: Analysis of Healthcare Utilization Data
- Author
-
Henrik Salje, Stephen P. Luby, Katharine Sturm-Ramirez, Simon Cauchemez, Nusrat Homaira, Birgit Nikolay, Mahmudur Rahman, A. Danielle Iuliano, Emily S. Gurley, Makhdum Ahmed, M. Jahangir Hossain, Eduardo Azziz-Baumgartner, Repon C. Paul, Modélisation mathématique des maladies infectieuses, Centre National de la Recherche Scientifique (CNRS)-Institut Pasteur [Paris], Centre de Bioinformatique, Biostatistique et Biologie Intégrative (C3BI), Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Johns Hopkins Bloomberg School of Public Health [Baltimore], Johns Hopkins University (JHU), Centers for Disease Control and Prevention [Atlanta] (CDC), Centers for Disease Control and Prevention, International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), University of New South Wales [Sydney] (UNSW), The University of Texas Health Science Center at Houston (UTHealth), The University of Texas M.D. Anderson Cancer Center [Houston], Institute of Epidemiology, Medical Research Council Unit The Gambia (MRC), Stanford University, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Ahmed, Makhdum [0000-0002-0772-8710], Rahman, Mahmudur [0000-0002-3698-4852], Luby, Stephen P [0000-0001-5385-899X], and Apollo - University of Cambridge Repository
- Subjects
Pulmonology ,Epidemiology ,Health Care Providers ,health care facilities, manpower, and services ,Disease ,MESH: Hospitalization ,Disease Outbreaks ,Geographical Locations ,0302 clinical medicine ,Central Nervous System Infections ,Infectious Diseases of the Nervous System ,[MATH.MATH-ST]Mathematics [math]/Statistics [math.ST] ,Medicine and Health Sciences ,Public and Occupational Health ,030212 general & internal medicine ,MESH: Disease Outbreaks ,Respiratory Tract Infections ,health care economics and organizations ,Disease surveillance ,Bangladesh ,Respiratory tract infections ,1. No poverty ,General Medicine ,Hospital based ,MESH: Hospitals ,Hospitals ,3. Good health ,Hospitalization ,Infectious Diseases ,Neurology ,Population Surveillance ,Medicine ,Medical emergency ,MESH: Bangladesh ,Research Article ,medicine.medical_specialty ,Asia ,Infectious Disease Control ,MESH: Central Nervous System Infections ,030231 tropical medicine ,education ,Disease Surveillance ,Sensitivity and Specificity ,International Health Regulations ,MESH: Population Surveillance ,03 medical and health sciences ,medicine ,Humans ,MESH: Humans ,business.industry ,Public health ,Outbreak ,medicine.disease ,MESH: Sensitivity and Specificity ,Health Care ,Infectious Disease Surveillance ,Emergency medicine ,People and Places ,Respiratory Infections ,MESH: Respiratory Tract Infections ,business - Abstract
Background The International Health Regulations outline core requirements to ensure the detection of public health threats of international concern. Assessing the capacity of surveillance systems to detect these threats is crucial for evaluating a country’s ability to meet these requirements. Methods and Findings We propose a framework to evaluate the sensitivity and representativeness of hospital-based surveillance and apply it to severe neurological infectious diseases and fatal respiratory infectious diseases in Bangladesh. We identified cases in selected communities within surveillance hospital catchment areas using key informant and house-to-house surveys and ascertained where cases had sought care. We estimated the probability of surveillance detecting different sized outbreaks by distance from the surveillance hospital and compared characteristics of cases identified in the community and cases attending surveillance hospitals. We estimated that surveillance detected 26% (95% CI 18%–33%) of severe neurological disease cases and 18% (95% CI 16%–21%) of fatal respiratory disease cases residing at 10 km distance from a surveillance hospital. Detection probabilities decreased markedly with distance. The probability of detecting small outbreaks (three cases) dropped below 50% at distances greater than 26 km for severe neurological disease and at distances greater than 7 km for fatal respiratory disease. Characteristics of cases attending surveillance hospitals were largely representative of all cases; however, neurological disease cases aged, Henrik Salje and colleagues propose a framework to examine the capacity of hospital-based surveillance data to detect public health threats in Bangladesh., Author Summary Why Was This Study Done? Many countries rely on hospital-based surveillance for the detection of infectious diseases of national and global public health relevance. It is often difficult to access suitable external reference data to assess the capacity of a surveillance system to detect cases and outbreaks or to characterize cases. What Did the Researchers Do and Find? We demonstrate a novel approach using healthcare utilization data to evaluate the sensitivity and representativeness of severe infectious disease surveillance in Bangladesh. The capacity to detect cases and outbreaks decreased with distance from surveillance hospitals. Cases captured by surveillance differed from cases in communities by age and socioeconomic status. Geographic coverage of surveillance could be improved by including other hospitals in the surveillance system. What Do These Findings Mean? The presented approach is applicable for a wide range of infectious diseases in different settings, taking some practical considerations into account. Hospital-based surveillance may have low sensitivity in rural areas at greater distances from surveillance hospitals, suggesting a risk of unrecognized transmission of emerging infectious diseases. Alternative surveillance strategies, such as including additional hospitals in the surveillance system or considering alternative data streams, may help to increase surveillance performance in such remote regions.
- Published
- 2017
40. Socioeconomic and environmental determinants of dengue transmission in an urban setting: An ecological study in Nouméa, New Caledonia
- Author
-
Marc Despinoy, Morgan Mangeas, Alizé Mercier, Christophe E. Menkès, Birgit Nikolay, Magali Teurlai, Jorge Cano, Myrielle Dupont-Rouzeyrol, François Taglioni, Raphaël M. Zellweger, Institut Pasteur de Nouvelle-Calédonie, Réseau International des Instituts Pasteur (RIIP), Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine (LSHTM), UMR 228 Espace-Dev, Espace pour le développement, Institut de Recherche pour le Développement (IRD)-Université de Perpignan Via Domitia (UPVD)-Avignon Université (AU)-Université de La Réunion (UR)-Université de Montpellier (UM)-Université de Guyane (UG)-Université des Antilles (UA), Centre de Recherche en Géographie de l'Université de La Réunion (CREGUR), Océan Indien : Espaces et Sociétés (OIES), Université de La Réunion (UR)-Université de La Réunion (UR), Pôle de recherche pour l'organisation et la diffusion de l'information géographique (PRODIG), Université Paris 1 Panthéon-Sorbonne (UP1)-Institut de Recherche pour le Développement (IRD)-Université Paris-Sorbonne (UP4)-AgroParisTech-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Animal, Santé, Territoires, Risques et Ecosystèmes (UMR ASTRE), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA), Processus de couplage à Petite Echelle, Ecosystèmes et Prédateurs Supérieurs (PEPS), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Modélisation mathématique des maladies infectieuses, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), This work was supported by Grant Ministere des Outre Mer, French State, subvention no 12-02412-D to MM and FT and an EU Grant Leonardo da Vinci to AM., Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Université de Guyane (UG)-Université des Antilles (UA)-Institut de Recherche pour le Développement (IRD)-Université de Perpignan Via Domitia (UPVD)-Avignon Université (AU)-Université de La Réunion (UR)-Université de Montpellier (UM), Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Zellweger, Raphaël M., Université des Antilles (UA)-Université de Guyane (UG)-Université de Montpellier (UM)-Université de La Réunion (UR)-Avignon Université (AU)-Université de Perpignan Via Domitia (UPVD)-Institut de Recherche pour le Développement (IRD), Université Paris Diderot - Paris 7 (UPD7)-Institut de Recherche pour le Développement (IRD)-Université Paris-Sorbonne (UP4)-AgroParisTech-Université Panthéon-Sorbonne (UP1)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN), Centre National de la Recherche Scientifique (CNRS)-Institut Pasteur [Paris], Réseau International des Instituts Pasteur ( RIIP ) -Institut Pasteur de Nouvelle-Calédonie, London School of Hygiene and Tropical Medicine ( LSHTM ), Université des Antilles ( UA ) -Université de Guyane ( UG ) -Université de Montpellier ( UM ) -Université de la Réunion ( UR ) -Université d'Avignon et des Pays de Vaucluse ( UAPV ) -Université Nice Sophia Antipolis ( UNS ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Université de Perpignan Via Domitia ( UPVD ) -Institut de Recherche pour le Développement ( IRD ), Centre de Recherche en Géographie de l'Université de La Réunion ( CREGUR ), Océan Indien : Espaces et Sociétés ( OIES ), Université de la Réunion ( UR ) -Université de la Réunion ( UR ), Pôle de recherche pour l'organisation et la diffusion de l'information géographique ( PRODIG ), Centre National de la Recherche Scientifique ( CNRS ) -Université Panthéon-Sorbonne ( UP1 ) -AgroParisTech-Université Paris-Sorbonne ( UP4 ) -Institut de Recherche pour le Développement ( IRD ) -Université Paris Diderot - Paris 7 ( UPD7 ), Contrôle des maladies animales exotiques et émergentes [Montpellier] ( CMAEE ), Institut National de la Recherche Agronomique ( INRA ) -Centre de coopération internationale en recherche agronomique pour le développement [CIRAD] : UMR15, Processus de couplage à Petite Echelle, Ecosystèmes et Prédateurs Supérieurs ( PEPS ), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques ( LOCEAN ), Muséum National d'Histoire Naturelle ( MNHN ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Muséum National d'Histoire Naturelle ( MNHN ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), and Institut Pasteur [Paris]-Centre National de la Recherche Scientifique ( CNRS )
- Subjects
Epidemiology ,Social Sciences ,Dengue virus ,Pathology and Laboratory Medicine ,Geographical locations ,0302 clinical medicine ,[INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing ,ComputingMilieux_MISCELLANEOUS ,education.field_of_study ,Geography ,[SDE.IE]Environmental Sciences/Environmental Engineering ,Incidence ,contexte socioéconomique ,Spatial epidemiology ,[ SDV.SPEE ] Life Sciences [q-bio]/Santé publique et épidémiologie ,3. Good health ,Medical Microbiology ,Viral Pathogens ,Physical Sciences ,Cements ,lcsh:RC955-962 ,Materials Science ,Environment ,Human Geography ,Microbiology ,[ SDV.EE.SANT ] Life Sciences [q-bio]/Ecology, environment/Health ,03 medical and health sciences ,Population Metrics ,transmission de virus ,Binders ,Disease Transmission, Infectious ,Humans ,education ,Microbial Pathogens ,Socioeconomic status ,Materials by Attribute ,Survey Research ,Flaviviruses ,Organisms ,Public Health, Environmental and Occupational Health ,Biology and Life Sciences ,Ecological study ,lcsh:RA1-1270 ,medicine.disease ,Invertebrates ,dengue ,Insect Vectors ,Species Interactions ,People and places ,RNA viruses ,Disease Vectors ,[INFO.INFO-NE]Computer Science [cs]/Neural and Evolutionary Computing [cs.NE] ,medicine.disease_cause ,Mosquitoes ,Dengue fever ,Medicine and Health Sciences ,030212 general & internal medicine ,condition environnementale ,lcsh:Public aspects of medicine ,Incidence (epidemiology) ,infections à arbovirus ,Insects ,Infectious Diseases ,Research Design ,[INFO.INFO-TI]Computer Science [cs]/Image Processing [eess.IV] ,Viruses ,Neighborhoods ,Topography, Medical ,Pathogens ,[SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing ,Research Article ,Adult ,Census ,lcsh:Arctic medicine. Tropical medicine ,Arthropoda ,Oceania ,030231 tropical medicine ,Population ,Research and Analysis Methods ,modèle mathématique ,New Caledonia ,Urbanization ,Environmental health ,medicine ,Animals ,Cities ,[SDV.EE.SANT]Life Sciences [q-bio]/Ecology, environment/Health ,Population Biology ,arbovirus ,Socioeconomic Factors ,virus dengue type 2 ,Earth Sciences ,nouvelle calédonie ,Population density ,[SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie - Abstract
Background Dengue is a mosquito-borne virus that causes extensive morbidity and economic loss in many tropical and subtropical regions of the world. Often present in cities, dengue virus is rapidly spreading due to urbanization, climate change and increased human movements. Dengue cases are often heterogeneously distributed throughout cities, suggesting that small-scale determinants influence dengue urban transmission. A better understanding of these determinants is crucial to efficiently target prevention measures such as vector control and education. The aim of this study was to determine which socioeconomic and environmental determinants were associated with dengue incidence in an urban setting in the Pacific. Methodology An ecological study was performed using data summarized by neighborhood (i.e. the neighborhood is the unit of analysis) from two dengue epidemics (2008–2009 and 2012–2013) in the city of Nouméa, the capital of New Caledonia. Spatial patterns and hotspots of dengue transmission were assessed using global and local Moran’s I statistics. Multivariable negative binomial regression models were used to investigate the association between dengue incidence and various socioeconomic and environmental factors throughout the city. Principal findings The 2008–2009 epidemic was spatially structured, with clusters of high and low incidence neighborhoods. In 2012–2013, dengue incidence rates were more homogeneous throughout the city. In all models tested, higher dengue incidence rates were consistently associated with lower socioeconomic status (higher unemployment, lower revenue or higher percentage of population born in the Pacific, which are interrelated). A higher percentage of apartments was associated with lower dengue incidence rates during both epidemics in all models but one. A link between vegetation coverage and dengue incidence rates was also detected, but the link varied depending on the model used. Conclusions This study demonstrates a robust spatial association between dengue incidence rates and socioeconomic status across the different neighborhoods of the city of Nouméa. Our findings provide useful information to guide policy and help target dengue prevention efforts where they are needed most., Author summary Dengue virus is rapidly spreading throughout tropical and subtropical regions worldwide, possibly aided by environmental change, urbanization and/or increase in human mobility. Already present in 120 countries, dengue virus causes extensive disease burden and generates large economic costs. As dengue is mosquito-borne, its transmission pattern is strongly influenced by climate. However, dengue cases are not always distributed evenly throughout cities, where climate can be assumed to be homogenous. This suggests that other factors which are heterogeneously distributed in cities could play a role in dengue transmission, such as socioeconomic status and environmental factors (both natural and built). Identifying those factors is crucial to develop and target dengue prevention interventions, such as mosquito control and education. Our study uses dengue incidence statistics from two large epidemics in Nouméa, the capital of New Caledonia, to investigate which socioeconomic or environmental factors correlate with dengue incidence in an urban setting. Dengue incidence was consistently higher in neighborhoods where socioeconomic status was lower (i.e. lower revenue or higher unemployment) and often higher where the proportion of single-family houses in all buildings was higher. Our data suggest that, if resources are limited, prevention measures should be targeted in priority towards neighborhoods of lower socioeconomic status.
- Published
- 2017
41. Development of a Usutu virus specific real-time reverse transcription PCR assay based on sequenced strains from Africa and Europe
- Author
-
Cheikh Saad Bouh Boye, Anne Dupressoir, Amadou A. Sall, Manfred Weidmann, Ousmane Faye, Birgit Nikolay, and Mawlouth Diallo
- Subjects
Context (language use) ,Biology ,Real-Time Polymerase Chain Reaction ,Sensitivity and Specificity ,Virus ,Flavivirus Infections ,Usutu virus ,Flavivirus ,Real-time RT-PCR ,Diagnosis ,Standard RNA ,03 medical and health sciences ,Virology ,Humans ,Genetic variability ,DNA Primers ,030304 developmental biology ,0303 health sciences ,Reverse Transcriptase Polymerase Chain Reaction ,030306 microbiology ,Encephalitis, Arbovirus ,biology.organism_classification ,Reverse transcriptase ,3. Good health ,Europe ,Reverse transcription polymerase chain reaction ,Real-time polymerase chain reaction ,Encephalitis Viruses, Japanese ,Africa - Abstract
Usutu virus (USUV) has been isolated in several African and European countries mainly from mosquitoes and birds. However, previous benign and two recent severe cases of human infections point out the need of a tool for the identification of USUV in human samples. A published real-time reverse transcription (RT) PCR assay for the detection of USUV in human blood or cerebrospinal fluid does not take into account the genetic variability of USUV in different geographic regions. Therefore, this article presents a quantitative real-time RT-PCR assay based on sequences from Europe and Africa. Primers and probe were designed in conserved regions among USUV strains that differed from closely related flaviviruses. The specificity of the assay was investigated by testing 16 other flaviviruses circulating in Africa. The sensitivity was determined by testing serial dilutions of virus and RNA standard. Intra- and inter-assay coefficients of variation were evaluated by 10 reactions in a same and in different assays, respectively. The assay provides high analytical specificity for USUV and detection limits of 1.2pfu/reaction for virus dilutions in L-15 medium or human serum and 60 copies/reaction for the RNA standard. The assay needs to be evaluated in a clinical context and integrated in standard diagnosis of flaviviral diseases. peerReviewed
- Published
- 2014
42. Enterovirus outbreak dynamics
- Author
-
Birgit Nikolay and Simon Cauchemez
- Subjects
0301 basic medicine ,Multidisciplinary ,business.industry ,viruses ,030106 microbiology ,Outbreak ,medicine.disease_cause ,Virology ,Article ,Disease Outbreaks ,03 medical and health sciences ,0302 clinical medicine ,Enterovirus Infections ,Humans ,Medicine ,Enterovirus ,030212 general & internal medicine ,business - Abstract
Human enteroviruses are a major cause of neurological and other diseases. Over 100 serotypes are known that exhibit unexplained complex patterns of incidence, from regular cycles to more irregular patterns, and new emergences. Using 15 years of surveillance data from Japan (2000-2014) and a stochastic transmission model with accurate demography, we show that acquired serotype-specific immunity can explain the diverse patterns of 18 of the 20 most common serotypes (including Coxsackieviruses, Echoviruses and Enterovirus-A71). The remaining two serotypes required a change in viral characteristics, including an increase in pathogenicity for Coxsackievirus-A6, consistent with its recent global rise in incidence. Based on our findings, we are able to predict outbreaks two years ahead of time (2015-2016). These results have implications for the impact of vaccines under development.
- Published
- 2018
43. Spread of yellow fever virus outbreak in Angola and the Democratic Republic of the Congo 2015–16: a modelling study
- Author
-
Kraemer, Moritz U. G., Faria, Nuno R., Reiner, Robert C., Nick, Golding, Birgit, Nikolay, Stephanie, Stasse, Johansson, Michael A., Henrik, Salje, Ousmane, Faye, William Wint, G. R., Matthias, Niedrig, Shearer, Freya M., Hill, Sarah C., Thompson, Robin N., Donal, Bisanzio, Nuno, Taveira, Nax, Harald, Pradelski, Bary S. R., Nsoesie, Elaine O., Nicholas, R Murphy, Bogoch, Isaac I., Kamran, Khan, Brownstein, John S., Tatem, Andrew J., and Tulio De Oliveira
- Subjects
Settore FIS/07 - Fisica Applicata(Beni Culturali, Ambientali, Biol.e Medicin) - Published
- 2016
44. Plasmodium falciparum parasitaemia and clinical malaria among school children living in a high transmission setting in western Kenya
- Author
-
Jorge Cano, Charles Mwandawiro, Joaniter I. Nankabirwa, Damaris Matoke-Muhia, Juliet Ndibazza, Simon Brooker, Katherine E. Halliday, Birgit Nikolay, Rachel L. Pullan, Elizabeth Allen, Stella Kepha, and Fred Nuwaha
- Subjects
Male ,Pediatrics ,medicine.medical_specialty ,Adolescent ,030231 tropical medicine ,Anaemia ,Parasitemia ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,Randomized controlled trial ,law ,Risk Factors ,School children ,parasitic diseases ,Prevalence ,Medicine ,Humans ,030212 general & internal medicine ,Malaria, Falciparum ,Child ,Socioeconomic status ,Randomized Controlled Trials as Topic ,2. Zero hunger ,Schools ,biology ,business.industry ,Transmission (medicine) ,Incidence (epidemiology) ,Public health ,Research ,Plasmodium falciparum ,Anemia ,biology.organism_classification ,medicine.disease ,Kenya ,3. Good health ,Malaria ,Infectious Diseases ,Cross-Sectional Studies ,Child, Preschool ,Tropical medicine ,Parasitology ,Female ,business ,Demography ,Follow-Up Studies - Abstract
Background Malaria among school children is increasingly receiving attention, yet the burden of malaria in this age group is poorly defined. This study presents data on malaria morbidity among school children in Bungoma county, western Kenya. Method This study investigated the burden and risk factors of Plasmodium falciparum infection, clinical malaria, and anaemia among 2346 school children aged 5–15 years, who were enrolled in an individually randomized trial evaluating the effect of anthelmintic treatment on the risks of malaria. At baseline, children were assessed for anaemia and nutritional status and information on household characteristics was collected. Children were followed-up for 13 months to assess the incidence of clinical malaria by active detection, and P. falciparum infection and density evaluated using repeated cross-sectional surveys over 15 months. Results On average prevalence of P. falciparum infection was 42 % and ranged between 32 and 48 % during the five cross-sectional surveys. Plasmodium falciparum prevalence was significantly higher among boys than girls. The overall incidence of clinical malaria was 0.26 episodes per person year (95 % confidence interval, 0.24–0.29) and was significantly higher among girls (0.23 versus 0.31, episodes per person years). Both infection prevalence and clinical disease varied by season. In multivariable analysis, P. falciparum infection was associated with being male, lower socioeconomic status and stunting. The risk of clinical malaria was associated with being female. Conclusion These findings show that the burden of P. falciparum parasitaemia, clinical malaria and anaemia among school children is not insignificant, and suggest that malaria control programmes should be expanded to include this age group. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1176-y) contains supplementary material, which is available to authorized users.
- Published
- 2015
45. Interrupting transmission of soil-transmitted helminths : a study protocol for cluster randomised trials evaluating alternative treatment strategies and delivery systems in Kenya\ud
- Author
-
Charles Mwandawiro, Caroline Teti, Birgit Nikolay, Ulla K. Griffiths, Claire Gwayi-Chore, Matthew C. Freeman, Hugo C. Turner, Doris W. Njomo, Elizabeth Allen, Simon Brooker, James E. Truscott, Paul M. Gichuki, Dina Balabanova, Carlos Mcharo, Roy M. Anderson, Dorcas Alusala, Beatrice Wasunna, Rachel L. Pullan, T. Déirdre Hollingsworth, Sammy M. Njenga, Jimmy H. Kihara, Athuman Chiguzo, and Katherine E. Halliday
- Subjects
Male ,Research design ,Veterinary medicine ,Cross-sectional study ,Cost-Benefit Analysis ,Psychological intervention ,Global Health ,DISEASE ,Deworming ,Soil ,PROGRAMS ,Residence Characteristics ,Surveys and Questionnaires ,Protocol ,Medicine ,EPIDEMIOLOGY ,Longitudinal Studies ,Child ,Aged, 80 and over ,Anthelmintics ,NTD CONTROL ,Schools ,PARASITOLOGY ,General Medicine ,Middle Aged ,CHEMOTHERAPY ,Research Design ,Child, Preschool ,Neglected tropical diseases ,Female ,PUBLIC HEALTH ,HYGIENE ,Life Sciences & Biomedicine ,Adult ,medicine.medical_specialty ,Adolescent ,MASS ,Albendazole ,Disease cluster ,DIAGNOSIS ,Hookworm Infections ,Young Adult ,Medicine, General & Internal ,SANITATION ,Environmental health ,General & Internal Medicine ,Humans ,Aged ,Science & Technology ,business.industry ,Public health ,EFFICACY ,Kenya ,Focus group ,Cross-Sectional Studies ,Communicable Disease Control ,business ,INTESTINAL PARASITIC INFECTIONS ,RC - Abstract
Introduction: \ud In recent years, an unprecedented emphasis has been given to the control of neglected tropical diseases, including soil-transmitted helminths (STHs). The mainstay of STH control is school-based deworming (SBD), but mathematical modelling has shown that in all but very low transmission settings, SBD is unlikely to interrupt transmission, and that new treatment strategies are required. This study seeks to answer the question: is it possible to interrupt the transmission of STH, and, if so, what is the most costeffective treatment strategy and delivery system to achieve this goal?\ud \ud Methods and analysis: \ud Two cluster randomised trials are being implemented in contrasting settings in Kenya. The interventions are annual mass anthelmintic treatment delivered to preschool- and school-aged children, as part of a national SBD programme, or to entire communities, delivered by community health workers. Allocation to study group is by cluster, using predefined units used in public health provision—termed community units (CUs). CUs are randomised to one of three groups: receiving either (1) annual SBD; (2) annual community-based deworming (CBD); or (3) biannual CBD. The primary outcome measure is the prevalence of hookworm infection, assessed by four cross-sectional surveys. Secondary outcomes are prevalence of Ascaris lumbricoides and Trichuris trichiura, intensity of species infections and treatment coverage. Costs and cost-effectiveness will be evaluated. Among a random subsample of participants, worm burden and proportion of unfertilised eggs will be assessed longitudinally. A nested process evaluation, using semistructured interviews, focus group discussions and a stakeholder analysis, will investigate the community acceptability, feasibility and scale-up of each delivery system.\ud \ud Ethics and dissemination: \ud Study protocols have been reviewed and approved by the ethics committees of the Kenya Medical Research Institute and National Ethics Review Committee, and London School of Hygiene and Tropical Medicine. The study has a dedicated web site.\ud \ud Trial registration number: NCT02397772
- Published
- 2015
46. Understanding Heterogeneity in the Impact of National Neglected Tropical Disease Control Programmes: Evidence from School-Based Deworming in Kenya
- Author
-
Caroline Teti, Elizabeth Allen, Jorge Cano, Mariam T. Mwanje, Charles Mwandawiro, Collins Okoyo, Birgit Nikolay, Jimmy H. Kihara, Hugo C. Turner, Simon Brooker, Josh Garn, Matthew C. Freeman, Roy M. Anderson, Rachel L. Pullan, Sammy M. Njenga, Dorcas Alusala, and Hadley M. Sultani
- Subjects
Program evaluation ,Veterinary medicine ,medicine.medical_specialty ,lcsh:Arctic medicine. Tropical medicine ,Sanitation ,lcsh:RC955-962 ,media_common.quotation_subject ,Ancylostomiasis ,Deworming ,Hygiene ,Tropical Medicine ,Environmental health ,Prevalence ,Medicine ,Animals ,Humans ,Trichuriasis ,Improved sanitation ,Nematode Infections ,media_common ,School Health Services ,Medical And Health Sciences ,Ascariasis ,Science & Technology ,biology ,business.industry ,Public health ,Antinematodal Agents ,lcsh:Public aspects of medicine ,Public Health, Environmental and Occupational Health ,Neglected Diseases ,Water ,lcsh:RA1-1270 ,Monitoring and evaluation ,Biological Sciences ,biology.organism_classification ,Kenya ,Infectious Diseases ,Socioeconomic Factors ,Parasitology ,Public Health ,Ascaris lumbricoides ,business ,Life Sciences & Biomedicine ,Delivery of Health Care ,Program Evaluation ,Research Article - Abstract
Background The implementation of soil-transmitted helminth (STH) treatment programmes occurs in varied environmental, social and economic contexts. Programme impact will be influenced by factors that affect the reduction in the prevalence and intensity of infections following treatment, as well as the subsequent rate of reinfection. To better understand the heterogeneity of programme impact and its underlying reasons, we investigated the influence of contextual factors on reduction in STH infection as part of the national school based deworming (SBD) programme in Kenya. Materials and Methods Data on the prevalence and intensity of infection were collected within the monitoring and evaluation component of the SBD programme at baseline and after delivery of two annual treatment rounds in 153 schools in western Kenya. Using a framework that considers STH epidemiology and transmission dynamics, capacity to deliver treatment, operational feasibility and financial capacity, data were assembled at both school and district (county) levels. Geographic heterogeneity of programme impact was assessed by descriptive and spatial analyses. Factors associated with absolute reductions of Ascaris lumbricoides and hookworm infection prevalence and intensity were identified using mixed effects linear regression modelling adjusting for baseline infection levels. Principal Findings The reduction in prevalence and intensity of A. lumbricoides and hookworms varied significantly by county and within counties by school. Multivariable analysis of factors associated with programme impact showed that absolute A. lumbricoides reductions varied by environmental conditions and access to improved sanitation at schools or within the community. Larger reduction in prevalence and intensity of hookworms were found in schools located within areas with higher community level access to improved sanitation and within counties with higher economic and health service delivery indicator scores. Conclusions The study identifies factors associated with the impact of school-based deworming and in particular highlights how access to water, sanitation and hygiene and environmental conditions influence the impact of deworming programmes., Author Summary Most countries with endemic soil-transmitted helminth (STH) infections have started implementing deworming programmes in recent years. However, the achievable impact on the prevalence and intensity of infections will depend on the socioeconomic and environmental context in which the programme is implemented. We use a previously developed framework that considers the epidemiology of STH transmission, capacity to deliver treatment, operational and financial feasibility, to investigate reasons for the observed within-country variation of deworming programme impact based on data from the national school based deworming programme in Kenya. The study demonstrates that programme impact varied markedly within the country and that reductions in STH infection were associated with levels of access to water, sanitation and hygiene (at schools or within communities). The described framework can help to identify areas where lower programme impact can be expected, and also to determine which additional interventions should be implemented in support of the deworming efforts.
- Published
- 2015
47. Associations between school- and household-level water, sanitation and hygiene conditions and soil-transmitted helminth infection among Kenyan school children
- Author
-
Simon Brooker, Matthew C. Freeman, Jimmy H. Kihara, Charles Mwandawiro, Birgit Nikolay, Collins Okoyo, Joshua V. Garn, Rachel L. Pullan, Anna N. Chard, and Sammy M. Njenga
- Subjects
medicine.medical_specialty ,Kenya ,Veterinary medicine ,Sanitation ,media_common.quotation_subject ,education ,030231 tropical medicine ,Helminthiasis ,Water supply ,Soil ,03 medical and health sciences ,0302 clinical medicine ,Risk Factors ,Hygiene ,Water Quality ,Environmental health ,Odds Ratio ,Humans ,Medicine ,030212 general & internal medicine ,Child ,Mass drug administration ,media_common ,2. Zero hunger ,Family Characteristics ,Schools ,business.industry ,Transmission (medicine) ,Research ,medicine.disease ,3. Good health ,Infectious Diseases ,Tropical medicine ,Parasitology ,business - Abstract
Background Soil-transmitted helminths, a class of parasitic intestinal worms, are pervasive in many low-income settings. Infection among children can lead to poor nutritional outcomes, anaemia, and reduced cognition. Mass treatment, typically administered through schools, with yearly or biannual drugs is inexpensive and can reduce worm burden, but reinfection can occur rapidly. Access to and use of sanitation facilities and proper hygiene can reduce infection, but rigorous data are scarce. Among school-age children, infection can occur at home or at school, but little is known about the relative importance of WASH in transmission in these two settings. Methods We explored the relationships between school and household water, sanitation, and hygiene conditions and behaviours during the baseline of a large-scale mass drug administration programme in Kenya. We assessed several WASH measures to quantify the exposure of school children, and developed theory and empirically-based parsimonious models. Results Results suggest mixed impacts of household and school WASH on prevalence and intensity of infection. WASH risk factors differed across individual worm species, which is expected given the different mechanisms of infection. Conclusions No trend of the relative importance of school versus household-level WASH emerged, though some factors, like water supply were more strongly related to lower infection, which suggests it is important in supporting other school practices, such as hand-washing and keeping school toilets clean. Electronic supplementary material The online version of this article (doi:10.1186/s13071-015-1024-x) contains supplementary material, which is available to authorized users.
- Published
- 2015
48. Epidemiology of coinfection with soil transmitted helminths and Plasmodium falciparum among school children in Bumula District in western Kenya
- Author
-
Simon Brooker, Elizabeth Allen, Charles Mwandawiro, Paul M. Gichuki, Tansy Edwards, Fred Nuwaha, Sammy M. Njenga, Stella Kepha, and Birgit Nikolay
- Subjects
Male ,Hookworm ,medicine.medical_specialty ,Veterinary medicine ,Adolescent ,Cross-sectional study ,Plasmodium falciparum ,Helminthiasis ,Deworming ,Soil ,Young Adult ,Helminths ,parasitic diseases ,Epidemiology ,Prevalence ,medicine ,Animals ,Humans ,Malaria, Falciparum ,Child ,Ascaris lumbricoides ,Hookworm infection ,Schools ,biology ,Coinfection ,Research ,medicine.disease ,biology.organism_classification ,Kenya ,3. Good health ,Cross-Sectional Studies ,Infectious Diseases ,Child, Preschool ,Soil transmitted helminths ,Female ,Parasitology ,Malaria ,Demography - Abstract
Background Many school children living in Africa are infected with plasmodia and helminth species and are consequently at risk of coinfection. However, the epidemiology of such coinfection and the implications of coinfection for children’s health remain poorly understood. This study describes the epidemiology of Ascaris lumbricoides-Plasmodium and hookworm-Plasmodium coinfection among school children living in western Kenya and investigates the associated risk factors. Methods As part of a randomized trial, a baseline cross-sectional survey was conducted among school children aged 5–18 years in 23 schools in Bumula District. Single stool samples were collected to screen for helminth infections using the Kato-Katz technique and malaria parasitaemia was determined from a finger prick blood sample. Demographic and anthropometric data were also collected. Results Overall, 46.4 % of the children were infected with Plasmodium falciparum while 27.6 % of the children were infected with at least one soil transmitted helminth (STH) species, with hookworm being the most common (16.8 %) followed by A. lumbricoides (15.3 %). Overall 14.3 % of the children had STH-Plasmodium coinfection, with hookworm-Plasmodium (9.0 %) coinfection being the most common. Geographical variation in the prevalence of coinfection occurred between schools. In multivariable logistic regression analysis, hookworm was positively associated with P. falciparum infection. In stratified analysis, hookworm infection was associated with increased odds of P. falciparum infection among both boys (P
- Published
- 2015
49. An investigation of the disparity in estimates of microfilaraemia and antigenaemia in lymphatic filariasis surveys
- Author
-
Jorge, Cano, Paula, Moraga, Birgit, Nikolay, Maria P, Rebollo, Patricia N, Okorie, Emmanuel, Davies, Sammy M, Njenga, Moses J, Bockarie, and Simon J, Brooker
- Subjects
Prevalence surveys ,Short Communications ,Logistic regression ,Antigenaemia ,Elephantiasis, Filarial ,Microfilaraemia ,Antigens, Helminth ,Surveys and Questionnaires ,parasitic diseases ,Carrier State ,Animals ,Humans ,Lymphatic filariasis ,Wuchereria bancrofti ,Microfilariae - Abstract
Background The diagnosis of lymphatic filariasis (LF) is based typically on either microfilaraemia as assessed by microscopy or filarial antigenaemia using an immuno-chromatographic test. While it is known that estimates of antigenaemia are generally higher than estimates of microfilaraemia, the extent of the difference is not known. Methods This paper presents the results of an extensive literature search for surveys that estimated both microfilaraemia and antigenaemia in order to better understand the disparity between the two measures. Results and Conclusions In some settings there was a very large disparity, up to 40–70%, between estimates of microfilaraemia and antigenaemia. Regression analysis was unable to identify any predictable relationship between the two measures. The implications of findings for risk mapping and surveillance of LF are discussed.
- Published
- 2015
50. Integrating data and resources on neglected tropical diseases for better planning: the NTD mapping tool (NTDmap.org)
- Author
-
Rachel L. Pullan, Jorge Cano, Huub C. Gelderblom, Adrian Hopkins, David G. Addiss, Rebecca M. Flueckiger, Jennifer L. Smith, Eric A. Ottesen, Simon Brooker, Alex Pavluck, Wesley Tack, Guy Hendrickx, Danny Haddad, Birgit Nikolay, and Danny R. Hatcher
- Subjects
Disease surveillance ,lcsh:Arctic medicine. Tropical medicine ,Knowledge management ,Resource (biology) ,Sanitation ,lcsh:RC955-962 ,business.industry ,lcsh:Public aspects of medicine ,Data management ,Public Health, Environmental and Occupational Health ,Psychological intervention ,lcsh:RA1-1270 ,Bioinformatics ,From Innovation to Application ,Infectious Diseases ,Global health ,Neglected tropical diseases ,Table (database) ,Medicine ,business - Abstract
Neglected tropical diseases (NTDs) affect more than 1,000,000,000 poor and marginalized people worldwide [1]. NTDs are caused by diverse pathogens with differing modes of transmission and a range of vectors and intermediate hosts, which have their own ecological peculiarities. While there is considerable overlap in the geographical distribution of different NTDs at a national level [1], epidemiological differences of individual NTDs give rise to marked geographical variation at local levels. Since cost-effectiveness of intervention is greatest when targeted to areas having a high burden of multiple diseases, maps of the distribution of the different NTDs are essential for planning and implementing NTD interventions, as well as for providing visualization of program progress, so important for advocacy. In recent years there have been concerted, and very successful, efforts to develop detailed information resources on the geographical distribution of different NTDs (Table 1). Table 1 Currently available resources on the geographical distribution of NTDs. An important element of targeted NTD intervention is the delivery of mass drug administration (MDA) for treating the five major “preventive chemotherapy” NTDs, including lymphatic filariasis (LF), onchocerciasis, schistosomiasis, soil-transmitted helminths (STH), and trachoma [2]. MDAs targeting these NTDs are implemented alongside improvements in water and sanitation and hygienic behavior, as well as vector control. To help galvanize such global health efforts, the World Health Organization (WHO) and the NTD community defined targets to be achieved by 2020 and strategies to reach these targets (Table 2). As countries make progress towards the 2020 goals with an ever-increasing amount of data being collected, it is important to develop readily accessible tools that policymakers and program staff and partners can use to access, visualize, and compare data. Table 2 The five main NTDs and the drugs and strategies used to target them programmatically. In this Innovation to Application article, we describe the creation of an innovative NTD mapping tool (www.ntdmap.org) developed by a consortium of research and program partners for use particularly by program implementers. Its functionality and accessibility have been designed specifically to meet the needs of national programs and international partners. This tool provides an online resource allowing users to visualize and manipulate geographical data on a range of variables for the planning and managing of integrated NTD programs.
- Published
- 2015
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.