6 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
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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
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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
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4. 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
5. Transmission of Antimicrobial Resistant Yersinia pestis during a Pneumonic Plague Outbreak
- Author
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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
6. 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
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