Search

ABSTRACT Objective: To estimate the probability of infection with hepatitis B (HBV) and C (HCV) viruses in different socioeconomic strata of the population of Recife, Northeast Brazil. Methods: Study carried out from samples obtained in a survey of residents of a large urban center that had a population base and stratified sampling with random selection of households using the “Brazil Sample” package in the R software. HBV (HBsAg) and anti-HCV was performed using immunochromatographic tests. In cases positive for HBsAg, anti-HBc and HBeAg were tested using chemiluminescence, as well as HBV-DNA using real-time PCR. For cases positive for anti-HCV, the search for this antibody was repeated by chemiluminescence and for HCV-RNA by real-time PCR. The occurrence of HBsAg and anti-HCV cases in the general population was estimated based on a theoretical negative binomial distribution. Results: Among 2,070 samples examined, 5 (0.24%) were HBsAg and 2 (0.1%) anti-HCV positive. The majority of cases had self-reported skin color as black/brown (6/7), education level up to high school (6/7), a steady partner (5/7) and lived in an area of low socioeconomic status (5/7). Conclusion : The occurrence of HBsAg and anti-HCV was lower than those previously found in population-based studies and slightly lower than the most recent estimates. Individuals with lower socioeconomic status should be a priority target of public health policies.

Abstract The need for the identification of risk factors associated to COVID-19 disease severity remains urgent. Patients’ care and resource allocation can be potentially different and are defined based on the current classification of disease severity. This classification is based on the analysis of clinical parameters and routine blood tests, which are not standardized across the globe. Some laboratory test alterations have been associated to COVID-19 severity, although these data are conflicting partly due to the different methodologies used across different studies. This study aimed to construct and validate a disease severity prediction model using machine learning (ML). Seventy-two patients admitted to a Brazilian hospital and diagnosed with COVID-19 through RT-PCR and/or ELISA, and with varying degrees of disease severity, were included in the study. Their electronic medical records and the results from daily blood tests were used to develop a ML model to predict disease severity. Using the above data set, a combination of five laboratorial biomarkers was identified as accurate predictors of COVID-19 severe disease with a ROC-AUC of 0.80 ± 0.13. Those biomarkers included prothrombin activity, ferritin, serum iron, ATTP and monocytes. The application of the devised ML model may help rationalize clinical decision and care.

BackgroundLymphatic filariasis (LF) is a stigmatizing and debilitating disease that represents a significant global public health challenge. Information regarding the knowledge and practices of individuals with filarial morbidities is limited, and this understanding is crucial for the implementation of effective control strategies. This study aimed to investigate the knowledge and practices of individuals with filarial morbidity residing in two intervention areas of the Elimination Program in the city of Olinda, Brazil.MethodsA cross-sectional study was carried out with residents who reported filarial morbidity in 2010, four years after the start of mass drug administration, in the intervention areas of the LF Elimination Program in the city of Olinda, Brazil. The knowledge and practices of patients with reported filarial morbidity in an endemic area were scrutinized using a semi-structured questionnaire to collect pertinent information. Data were analyzed utilizing the R language version 3.6.1.ResultsFilarial morbidity was reported in 338 patients. Dermatolymphangioadenitis emerged as the most frequently reported clinical form (50.9%). Mosquito bites were the most commonly cited form of transmission, accounting for 296 cases (87.6%). Approximately 80% (266) confirmed the adoption of prevention measures. Participants reported that the treatment involved the administration of medication. The existence of a cure for parasitosis was indicated by 212 subjects (62.7%).ConclusionsIndividuals with reported filarial morbidity exhibit varying levels of conceptions, knowledge, and practices regarding the disease, despite residing in an endemic area and receiving consistent visits from family health teams. Health services must identify shortcomings in this approach to minimize disparities, thereby enabling health education to effectively contribute to disease control and elimination in the municipality.

Background: COVID-19 is primarily known as a respiratory illness; however, many patients present to hospital without respiratory symptoms. The association between non-respiratory presentations of COVID-19 and outcomes remains unclear. We investigated risk factors and clinical outcomes in patients with no respiratory symptoms (NRS) and respiratory symptoms (RS) at hospital admission. Methods: This study describes clinical features, physiological parameters, and outcomes of hospitalised COVID-19 patients, stratified by the presence or absence of respiratory symptoms at hospital admission. RS patients had one or more of: cough, shortness of breath, sore throat, runny nose or wheezing; while NRS patients did not. Results: Of 178,640 patients in the study, 86.4 % presented with RS, while 13.6 % had NRS. NRS patients were older (median age: NRS: 74 vs RS: 65) and less likely to be admitted to the ICU (NRS: 36.7 % vs RS: 37.5 %). NRS patients had a higher crude in-hospital case-fatality ratio (NRS 41.1 % vs. RS 32.0 %), but a lower risk of death after adjusting for confounders (HR 0.88 [0.83–0.93]). Conclusion: Approximately one in seven COVID-19 patients presented at hospital admission without respiratory symptoms. These patients were older, had lower ICU admission rates, and had a lower risk of in-hospital mortality after adjusting for confounders.

Summary: Background: Improvements in the early diagnosis of dengue are urgently needed, especially in resource-limited settings where the distinction between dengue and other febrile illnesses is crucial for patient management. Methods: In this prospective, observational study (IDAMS), we included patients aged 5 years and older with undifferentiated fever at presentation from 26 outpatient facilities in eight countries (Bangladesh, Brazil, Cambodia, El Salvador, Indonesia, Malaysia, Venezuela, and Viet Nam). We used multivariable logistic regression to investigate the association between clinical symptoms and laboratory tests with dengue versus other febrile illnesses between day 2 and day 5 after onset of fever (ie, illness days). We built a set of candidate regression models including clinical and laboratory variables to reflect the need of a comprehensive versus parsimonious approach. We assessed performance of these models via standard measures of diagnostic values. Findings: Between Oct 18, 2011, and Aug 4, 2016, we recruited 7428 patients, of whom 2694 (36%) were diagnosed with laboratory-confirmed dengue and 2495 (34%) with (non-dengue) other febrile illnesses and met inclusion criteria, and were included in the analysis. 2703 (52%) of 5189 included patients were younger than 15 years, 2486 (48%) were aged 15 years or older, 2179 (42%) were female and 3010 (58%) were male. Platelet count, white blood cell count, and the change in these variables from the previous day of illness had a strong association with dengue. Cough and rhinitis had strong associations with other febrile illnesses, whereas bleeding, anorexia, and skin flush were generally associated with dengue. Model performance increased between day 2 and 5 of illness. The comprehensive model (18 clinical and laboratory predictors) had sensitivities of 0·80 to 0·87 and specificities of 0·80 to 0·91, whereas the parsimonious model (eight clinical and laboratory predictors) had sensitivities of 0·80 to 0·88 and specificities of 0·81 to 0·89. A model that includes laboratory markers that are easy to measure (eg, platelet count or white blood cell count) outperformed the models based on clinical variables only. Interpretation: Our results confirm the important role of platelet and white blood cell counts in diagnosing dengue, and the importance of serial measurements over subsequent days. We successfully quantified the performance of clinical and laboratory markers covering the early period of dengue. Resulting algorithms performed better than published schemes for distinction of dengue from other febrile illnesses, and take into account the dynamic changes over time. Our results provide crucial information needed for the update of guidelines, including the Integrated Management of Childhood Illness handbook. Funding: EU's Seventh Framework Programme. Translations: For the Bangla, Bahasa Indonesia, Portuguese, Khmer, Spanish and Vietnamese translations of the abstract see Supplementary Materials section.

Background: The mannose-binding lectin (MBL) plays an important role in innate immunity. Genetically determined variations in serum levels of MBL may influence the susceptibility and clinical outcome of dengue infection in early life. Methods: We investigated the MBL2 gene polymorphisms and serum levels of MBL (total and functional) in children with asymptomatic (n=17) and symptomatic (n=29) primary dengue infections and age-matched uninfected children (n=84) enrolled in a birth cohort with dengue in Brazil. Polymorphisms of the MBL2 gene were assessed by reverse transcription-polymerase chain reaction (RT-PCR), whereas the enzyme-linked immunosorbent assay (ELISA) was used to quantify serum levels of MBL. Results: We found that the X allele and YX genotype in the MBL2 were more frequent in the dengue cases than in the control group. Likewise, the LXPA haplotype was exclusively found in dengue cases, thus probably related to dengue infection in our setting. Moreover, we found a higher frequency of the O allele and AO genotype in the control group. Serum levels of total and functional MBL were higher in dengue naïve infants than in dengue cases. Conclusions: MBL2 variants related to lower production of serum MBL were associated with dengue infection in infants, whereas intermediate to high levels of total and functional serum MBL were associated with protection against dengue infection. These findings highlight the role of MBL2 variants and serum levels of MBL in the susceptibility of children to dengue disease at early ages.

Background: Elderly people have largely been vaccinated against severe acute respiratory syndrome coronavirus 2 (SARSCoV-2) because of their higher risk of coronavirus disease 2019 (COVID-19). Little is known about the efficacy of such vaccines in elderly people with cerebrovascular diseases. Method: Here, we present the preliminary results of serology (IgA and IgG) and molecular testing for SARS-CoV-2 in a case series of elderly patients who were admitted with an acute stroke and had received a single dose of the COVID-19 vaccine in a city of northeastern Brazil. Currently, we are enquiring from 11 Brazilian neurology centers for their data and openly inviting groups that are working in this field to collaborate. Results: Between January 28 and March 25, 14 patients with acute stroke and ages within the vaccine age ranges were admitted to our neurology center. Ten patients had received their first dose of the COVID-19 vaccine. Most patients were women over 80 years of age with vascular risk factors and ischemic stroke. Three patients aged >85 years had no anti-SARS-CoV-2 antibodies detectable. Three other patients had SARS-CoV-2 infection, among whom a man died a few days later. Conclusion: These cases exemplify how elderly people with cerebrovascular diseases and incomplete vaccination schemes can be susceptible to COVID-19.

Background The impact of the COVID-19 pandemic on paediatric populations varied between high-income countries (HICs) versus low-income to middle-income countries (LMICs). We sought to investigate differences in paediatric clinical outcomes and identify factors contributing to disparity between countries.Methods The International Severe Acute Respiratory and Emerging Infections Consortium (ISARIC) COVID-19 database was queried to include children under 19 years of age admitted to hospital from January 2020 to April 2021 with suspected or confirmed COVID-19 diagnosis. Univariate and multivariable analysis of contributing factors for mortality were assessed by country group (HICs vs LMICs) as defined by the World Bank criteria.Results A total of 12 860 children (3819 from 21 HICs and 9041 from 15 LMICs) participated in this study. Of these, 8961 were laboratory-confirmed and 3899 suspected COVID-19 cases. About 52% of LMICs children were black, and more than 40% were infants and adolescent. Overall in-hospital mortality rate (95% CI) was 3.3% [=(3.0% to 3.6%), higher in LMICs than HICs (4.0% (3.6% to 4.4%) and 1.7% (1.3% to 2.1%), respectively). There were significant differences between country income groups in intervention profile, with higher use of antibiotics, antivirals, corticosteroids, prone positioning, high flow nasal cannula, non-invasive and invasive mechanical ventilation in HICs. Out of the 439 mechanically ventilated children, mortality occurred in 106 (24.1%) subjects, which was higher in LMICs than HICs (89 (43.6%) vs 17 (7.2%) respectively). Pre-existing infectious comorbidities (tuberculosis and HIV) and some complications (bacterial pneumonia, acute respiratory distress syndrome and myocarditis) were significantly higher in LMICs compared with HICs. On multivariable analysis, LMIC as country income group was associated with increased risk of mortality (adjusted HR 4.73 (3.16 to 7.10)).Conclusion Mortality and morbidities were higher in LMICs than HICs, and it may be attributable to differences in patient demographics, complications and access to supportive and treatment modalities.

Introduction: Human Papillomavirus (HPV) is the primary etiologic agent of anogenital tract cancer. A higher prevalence and incidence of developing cancer and diseases associated with HPV have been observed in individuals infected with the human immunodeficiency virus (HIV). The natural history of HPV infection has not been completely elucidated, as well as the immune response that occurs as coinfection with HIV/HPV, particularly in the anal mucosa. Objective: To analyze the HPV prevalence and clinical, epidemiological, and behavioral data in a cohort of HIV-seropositive individuals from the National Institute of Infectious Diseases, FIOCRUZ, RJ. Methods: The study included a total of 114 individuals from the histopathological diagnosis of anal biopsy. PCR and sequencing was performed for HPV DNA identification in anal discharge. Statistical analysis was performed using SPSS 15.0 software. Results: Patients Infected with HIV with anal intraepithelial neoplasia (AIN) II/III had nadir CD4 +

We present a genome polymorphisms/machine learning approach for severe COVID-19 prognosis. Ninety-six Brazilian severe COVID-19 patients and controls were genotyped for 296 innate immunity loci. Our model used a feature selection algorithm, namely recursive feature elimination coupled with a support vector machine, to find the optimal loci classification subset, followed by a support vector machine with the linear kernel (SVM-LK) to classify patients into the severe COVID-19 group. The best features that were selected by the SVM-RFE method included 12 SNPs in 12 genes: PD-L1, PD-L2, IL10RA, JAK2, STAT1, IFIT1, IFIH1, DC-SIGNR, IFNB1, IRAK4, IRF1, and IL10. During the COVID-19 prognosis step by SVM-LK, the metrics were: 85% accuracy, 80% sensitivity, and 90% specificity. In comparison, univariate analysis under the 12 selected SNPs showed some highlights for individual variant alleles that represented risk (PD-L1 and IFIT1) or protection (JAK2 and IFIH1). Variant genotypes carrying risk effects were represented by PD-L2 and IFIT1 genes. The proposed complex classification method can be used to identify individuals who are at a high risk of developing severe COVID-19 outcomes even in uninfected conditions, which is a disruptive concept in COVID-19 prognosis. Our results suggest that the genetic context is an important factor in the development of severe COVID-19.

ABSTRACT OBJECTIVE: To verify the effectiveness of screening for tuberculosis (TB) on all-cause mortality and tuberculosis cases in newly diagnosed HIV-infected patients through a clinical algorithm based on recommendations of the World Health Organization. METHODS: From March 2014 to April 2016, a pragmatic randomized clinical trial was conducted with newly diagnosed and TB-free HIV-infected adults undergoing antiretroviral therapy for up to one month at a major tertiary hospital for HIV in the state of Pernambuco, Brazil. Participants were randomized into intervention and control groups using an automatically-generated random list, and followed-up for at least 6 months. The intervention group was screened for TB at hospital admission and at every follow-up visit through a series of questions addressing TB-related symptoms (cough, fever, night sweating, and weight loss). Patients presenting with any of these symptoms were referred to a pulmonologist and underwent sputum smear microscopy, sputum culture, and rapid molecular testing (GeneXpert). When at least one test result came back positive, TB treatment was initiated. In turn, if patients tested negative but presented with severe clinal symptoms, TB preventive treatment was initiated. Screening for TB was not performed systematically in the control group. The primary outcome assessed in this study was death from all causes, and secondary outcomes included sensitivity and specificity of this screening test, as well as its detection time. RESULTS: This study evaluated 581 patients, 377 in the intervention group (64.9%) and 204 in the control group (35.1%). In total, 36 patients died during the follow-up period. Of these, 26 (6.9%) were from the intervention group, reaching a cumulative mortality coefficient of 69 per 1,000 inhabitants, and 10 (4.9%) from the control group (p = 0.341), with a cumulative mortality coefficient of 49 per 1,000 inhabitants (p = 0.341).

BackgroundSerological diagnosis of Zika virus (ZIKV) infection is challenging because of the antibody cross-reactivity among flaviviruses. At the same time, the role of Nucleic Acid Testing (NAT) is limited by the low proportion of symptomatic infections and the low average viral load. Here, we compared the diagnostic performance of commercially available IgM, IgAM, and IgG ELISAs in sequential samples during the ZIKV and chikungunya (CHIKV) epidemics and co-circulation of dengue virus (DENV) in Brazil and Venezuela.Methodology/principal findingsAcute (day of illness 1-5) and follow-up (day of illness ≥ 6) blood samples were collected from nine hundred and seven symptomatic patients enrolled in a prospective multicenter study between June 2012 and August 2016. Acute samples were tested by RT-PCR for ZIKV, DENV, and CHIKV. Acute and follow-up samples were tested for IgM, IgAM, and IgG antibodies to ZIKV using commercially available ELISAs. Among follow-up samples with a RT-PCR confirmed ZIKV infection, anti-ZIKV IgAM sensitivity was 93.5% (43/46), while IgM and IgG exhibited sensitivities of 30.3% (10/33) and 72% (18/25), respectively. An additional 24% (26/109) of ZIKV infections were detected via IgAM seroconversion in ZIKV/DENV/CHIKV RT-PCR negative patients. The specificity of anti-ZIKV IgM was estimated at 93% and that of IgAM at 85%.Conclusions/significanceOur findings exemplify the challenges of the assessment of test performance for ZIKV serological tests in the real-world setting, during co-circulation of DENV, ZIKV, and CHIKV. However, we can also demonstrate that the IgAM immunoassay exhibits superior sensitivity to detect ZIKV RT-PCR confirmed infections compared to IgG and IgM immunoassays. The IgAM assay also proves to be promising for detection of anti-ZIKV seroconversions in sequential samples, both in ZIKV PCR-positive as well as PCR-negative patients, making this a candidate assay for serological monitoring of pregnant women in future ZIKV outbreaks.

BACKGROUND Fluctuations in climate have been associated with variations in mosquito abundance. OBJECTIVES To analyse the influence of precipitation, temperature, solar radiation, wind speed and humidity on the oviposition dynamics of Aedes aegypti in three distinct environmental areas (Brasília Teimosa, Morro da Conceição/Alto José do Pinho and Dois Irmãos/Pintos) of the city of Recife and the Fernando de Noronha Archipelago northeastern Brazil. METHODS Time series study using a database of studies previously carried out in the areas. The eggs were collected using spatially distributed geo-referenced sentinel ovitraps (S-OVTs). Meteorological satellite data were obtained from the IRI climate data library. The association between meteorological variables and egg abundance was analysed using autoregressive models. FINDINGS Precipitation was positively associated with egg abundance in three of the four study areas with a lag of one month. Higher humidity (β = 45.7; 95% CI: 26.3 - 65.0) and lower wind speed (β = −125.2; 95% CI: −198.8 - −51.6) were associated with the average number of eggs in the hill area. MAIN CONCLUSIONS The effect of climate variables on oviposition varied according to local environmental conditions. Precipitation was a main predictor of egg abundance in the study settings.

Abstract Background Transmission dynamics, vectorial capacity, and co-infections have substantial impacts on vector-borne diseases (VBDs) affecting urban and suburban populations. Reviewing key factors can provide insight into priority research areas and offer suggestions for potential interventions. Main body Through a scoping review, we identify knowledge gaps on transmission dynamics, vectorial capacity, and co-infections regarding VBDs in urban areas. Peer-reviewed and grey literature published between 2000 and 2016 was searched. We screened abstracts and full texts to select studies. Using an extraction grid, we retrieved general data, results, lessons learned and recommendations, future research avenues, and practice implications. We classified studies by VBD and country/continent and identified relevant knowledge gaps. Of 773 articles selected for full-text screening, 50 were included in the review: 23 based on research in the Americas, 15 in Asia, 10 in Africa, and one each in Europe and Australia. The largest body of evidence concerning VBD epidemiology in urban areas concerned dengue and malaria. Other arboviruses covered included chikungunya and West Nile virus, other parasitic diseases such as leishmaniasis and trypanosomiasis, and bacterial rickettsiosis and plague. Most articles retrieved in our review combined transmission dynamics and vectorial capacity; only two combined transmission dynamics and co-infection. The review identified significant knowledge gaps on the role of asymptomatic individuals, the effects of co-infection and other host factors, and the impacts of climatic, environmental, and socioeconomic factors on VBD transmission in urban areas. Limitations included the trade-off from narrowing the search strategy (missing out on classical modelling studies), a lack of studies on co-infections, most studies being only descriptive, and few offering concrete public health recommendations. More research is needed on transmission risk in homes and workplaces, given increasingly dynamic and mobile populations. The lack of studies on co-infection hampers monitoring of infections transmitted by the same vector. Conclusions Strengthening VBD surveillance and control, particularly in asymptomatic cases and mobile populations, as well as using early warning tools to predict increasing transmission, were key strategies identified for public health policy and practice.

BackgroundThe objective of the Global Program to Eliminate Lymphatic Filariasis (GPELF) is to phase out this endemic disease as a public health problem by 2020. Validation of elimination is obtained from the World Health Organization through evidence of non-transmission in countries that have already been subjected to mass drug administration (MDA) and in places adjoining these endemic areas. While three municipalities in Brazil have completed MDA, the epidemiological situation remains uncertain in nine adjoining municipalities. To determine the epidemiological status, this study was to perform a review of the literature and a school-based survey to describe the past and recent endemicity of lymphatic filariasis (LF) theses nine municipalities in Brazil.Methodology/principle findingsFor review of the literature, both formal and informal literature sources were accessed since the first reports of filariasis in the Metropolitan Region of Recife, Brazil. We conducted a school-based survey in 2016 using immunochromatographic card tests (ICTs) among schoolchildren aged 6-10 years living in nine municipalities contiguous with the endemic areas in which MDA was conducted. Our review of the literature identified eight studies involving surveys demonstrating that microfilariae had been circulating in eight of the municipalities since 1967, with a low prevalence of microfilaremia, isolated autochthonous cases, and treatment of individual cases. The school-based survey included 17,222 children in 185 urban schools in the nine areas of Brazil with uncertain endemicity. One child affected by allochthonous transmission was antigen positive based on ICT and lived in a municipality adjacent to Recife; this child's family came from Recife, but no other case was diagnosed within the family.Conclusions/significanceThe study results suggest that there is no transmission of LF in the municipalities investigated. However, these areas have population migration and socioenvironmental conditions favorable to mosquito breeding grounds; therefore, surveillance is strongly recommended in these areas.

Background: The Recife Metropolitan Region (RMR), north-eastern Brazil, was the epicentre of the 2015 Zika virus (ZIKV) epidemic, which was followed by a 2016 chikungunya virus (CHIKV) epidemic. It historically has amongst the highest incidence of dengue virus (DENV) infections and is the only remaining focus of lymphatic filariasis (LF) in Brazil. In early 2015, a molecular xenomonitoring surveillance project focused on Culex (Cx.) quinquefasciatus commenced to inform LF elimination activities. Aedes (Ae.) aegypti mosquitoes were also collected, concurrent with the first microcephaly cases detected in the RMR. In terms of the 2015 ZIKV epidemic, these are the earliest known field-collected mosquitoes, preserved for potential RNA virus detection, when ZIKV was known to be circulating locally. Methods: Adult mosquitoes were collected in two sites (0.4 km2) of Sítio Novo, Olinda, RMR, from July 22 to August 21, 2015. Mosquitoes were morphologically identified, sorted by physiological status, and pooled (up to 10 mosquitoes per house per day or week). RNA was extracted, reverse transcribed and the cDNA tested by real-time PCR. Results: A total of 10,139 adult female Cx. quinquefasciatus and 939 adult female Ae. aegypti were captured. All female Ae. aegypti specimens were included within 156 pools and screened for ZIKV, DENV and CHIKV. In addition, a sub-set of 1,556 Cx. quinquefasciatus adult females in 182 pools were screened for ZIKV. No evidence of infection with any of the three arboviruses was found. Conclusions: The absence of arbovirus detection may have been expected given the extremely restricted geographic area and collection of mosquitoes during a very short time period of peak mosquito abundance (July–September), but low arbovirus circulation (November–March). However, this study demonstrates the potential to retrospectively screen for additional unexpected pathogens in situations of rapid emergence, such as occurred during the outbreak of ZIKV in the RMR.

Laboratory confirmation of Zika virus (ZIKV) infection during pregnancy is challenging due to cross-reactivity with dengue virus (DENV) and limited knowledge about the kinetics of anti-Zika antibody responses during pregnancy. We described ZIKV and DENV serological markers and the maternal-fetal transfer of antibodies among mothers and neonates after the ZIKV microcephaly outbreak in Northeast Brazil (2016). We included 89 microcephaly cases and 173 neonate controls at time of birth and their mothers. Microcephaly cases were defined as newborns with a particular head circumference (2 SD below the mean). Two controls without microcephaly were matched by the expected date of delivery and area of residence. We tested maternal serum for recent (ZIKV genome, IgM and IgG3 anti-NS1) and previous (ZIKV and DENV neutralizing antibodies [NAbs]) markers of infection. Multiple markers of recent or previous ZIKV and DENV infection in mothers were analyzed using principal component analysis (PCA). At delivery, 5.6% of microcephaly case mothers and 1.7% of control mothers were positive for ZIKV IgM. Positivity for ZIKV IgG3 anti-NS1 was 8.0% for case mothers and 3.5% for control mothers. ZIKV NAbs was slightly higher among mothers of cases (69.6%) than that of mothers of controls (57.2%; p = 0.054). DENV exposure was detected in 85.8% of all mothers. PCA discriminated two distinct components related to recent or previous ZIKV infection and DENV exposure. ZIKV NAbs were higher in newborns than in their corresponding mothers (p

The diagnostic of arbovirus-related obstetric complications in high-risk pregnancy and childbirth care is challenging, especially in endemic areas. We conducted a prospective study to track active or recent Zika (ZIKV), dengue (DENV), or chikungunya (CHIKV) virus infection among hospitalized pregnant women (PW) with obstetric complications in a hospital at the epicenter of Zika outbreak and ZIKV-related microcephaly in Brazil. Clinical data and blood samples were collected at enrollment and 10 days after the admission of study participants, between October 2018 and May 2019. Further clinical data were extracted from medical records. Samples were screened by molecular and serological tests. Out of 780 participants, 93.1% (95% CI: 91.1–94.7%) presented previous DENV exposure (IgG). ZIKV, CHIKV, and/or DENV laboratory markers of recent or active infection were detected in 130 PW, yielding a prevalence of 16.6% (95% CI: 14.2–19.5%); 9.4% (95% CI: 7.4–11.7%), 7.4% (95% CI: 5.7–9.7%), and 0.38% (95% CI: 0.1–1.2%) of CHIKV, ZIKV, and DENV infections, respectively. Most ZIKV infections were detected by molecular assays (89.6%), while CHIKV infections were detected by serology (95.9%). Our findings highlight the need for arbovirus infections screening in PW with obstetrical complications, potentially associated to these infections in endemic areas regardless of the signs or symptoms suggestive of arboviral disease.

In this Editorial, we list and discuss some of the main challenges faced by the population and public health authorities in Brazil concerning arbovirus infections, including the occurrence of concurrent epidemics like the ongoing SARS-CoV-2/COVID-19 pandemic.

INTRODUCTION:Molecular xenomonitoring (MX)-pathogen detection in the mosquito rather than human-is a promising tool for lymphatic filariasis (LF) surveillance. In the Recife Metropolitan Region (RMR), the last LF focus in Brazil, Culex quinquefasciatus mosquitoes have been implicated in transmitting Wuchereria bancrofti parasites. This paper presents findings on the ideal mosquito collection method, mosquito dispersion, W. bancrofti infection in mosquitoes and W. bancrofti antigen in humans to aid MX development. METHODS:Experiments occurred within two densely populated urban areas of Olinda, RMR, in July and August 2015. U.S. Centers for Disease Control and Prevention (CDC) light traps were compared to battery-powered aspirators as collection methods, and mosquito dispersion was measured by mosquito mark release recapture (MMRR). Female Cx. quinquefasciatus were tested by PCR for W. bancrofti infection, and study area residents were screened by rapid tests for W. bancrofti antigen. RESULTS:Aspirators caught 2.6 times more total Cx. quinquefasciatus, including 38 times more blood-fed and 5 times more gravid stages, than CDC light traps. They also collected 123 times more Aedes aegypti. Of the 9,644 marked mosquitoes released, only ten (0.01%) were recaptured, nine of which were < 50m (34.8m median, 85.4m maximum) from the release point. Of 9,169 unmarked mosquitoes captured in the MMR, 38.3% were unfed, 48.8% blood-fed, 5.5% semi-gravid, and 7.3% gravid. PCR on 182 pools (1,556 mosquitoes) found no evidence of W. bancrofti infection in Cx. quinquefasciatus. Rapid tests on 110 of 111 eligible residents were all negative for W. bancrofti antigen. CONCLUSIONS:Aspirators were more effective than CDC light traps at capturing Ae. aegypti and all but unfed stages of Cx. quinquefasciatus. Female Cx. quinquefasciatus traveled short (< 86m) distances in this urban area. Lack of evidence for W. bancrofti infection in mosquitoes and antigen in humans in these fine-scale studies does not indicate that LF transmission has ceased in the RMR. A MX surveillance system should consider vector-specific collection methods, mosquito dispersion, and spatial scale but also local context, environmental factors such as sanitation, and host factors such as infection prevalence and treatment history.

Several arboviruses, including dengue virus (DENV), Zika virus (ZIKV) and chikungunya virus (CHIKV), transmitted by Aedes mosquitoes, circulate in northeast Brazil. Diseases caused by these viruses are of great public health relevance, however, their epidemiological features in areas where the three viruses co-circulate are scarce. Here, we present analyses of molecular and serological diagnostics in a prospective study of acute febrile patients recruited from May 2015 to May 2016 in Recife, Brazil.Two hundred sixty-three acute febrile patients with symptoms suggestive of an arboviral disease who attended an urgent heath care clinic in the Recife Metropolitan Region in northeast Brazil were enrolled. Acute and convalescent blood samples were collected and tested using molecular and serological assays for infection with DENV, ZIKV and CHIKV.Quantitative real-time reverse-transcriptase polymerase chain reactions (qRTPCR) performed on acute phase sera detected no patients positive for DENV, but 26 (9.9%) positive for ZIKV and 132 (50.2%) positive for CHIKV. There were a few suspected and only one confirmed dengue case. Specific serological assays for ZIKV and CHIKV confirmed the qRTPCR data. Analyses of DENV IgM and IgG ELISAs in the context of qRTPCR results suggested high levels of cross reactive antibodies in ZIKV-positive samples. Results from neutralization assays highly corroborated those from qRTPCR and ZIKV ELISA, indicating very few positive DENV cases. ZIKV infections were temporally clustered in the first months of the study and started to decrease concomitantly with an increase in CHIKV infections in August 2015. The proportion of CHIKV infections increased significantly in September 2015 and remained high until the end of the study period, with an average of 84.7% of recruited patients being diagnosed from August 2015 to May 2016. ZIKV infections exhibited a female bias and the cases were spread over the study site, while CHIKV cases had a male bias and were spatially clustered in each month.In 2015-2016 in the Recife Metropolitan Region, we detected the tail end of a Zika epidemic, which was displaced by a chikungunya epidemic. Few dengue cases were identified despite a high number of official dengue notifications in the area during this period. We show here important epidemiological features of these cases.

Mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV) infection remains an important cause of new HIV infections worldwide, especially in low and middle-resource limited countries. Safety data from studies involving pregnant women and prenatal antiretroviral (ARV) exposure are still needed once these studies are often small and with a limited duration to assess adverse drug reactions (ADR). The aim of this study was to estimate the incidence of ADR related to the use of antiretroviral therapy (ART) in pregnant women in two referral centers in Rio de Janeiro State. A prospective study was carried out from February 2005 to May 2006. Women were classified according to their ART status during pregnancy diagnosis: ARV-experienced (ARTexp) or ARV-naïve (ARTn). Two hundred fourteen HIV-infected pregnant women were included: 36 ARTexp and 178 ARTn. ARTexp women have not experienced ADR. Among ARTn, 20.2% presented ADR. Incidence rate of ADR was 70.8 per 1000 person-months and the most common ADRs observed were: gastrointestinal (belly or abdominal cramps, diarrhea, nausea and vomit) in 16.3%, cutaneous (pruritus and rash) in 6.2%, anemia (2.2%) and hepatitis (1.7%). The frequency of obstetrical complications, pre-term delivery, low birth weight and birth abnormalities was low in this population. ADRs ranged from mild to moderate intensity, none of them being potentially fatal. Only in a few cases it was necessary to discontinue ART. In conclusion, the high effectiveness of ARV for HIV prevention of MTCT (PMTCT) overcomes the risk of ADR. Keywords: HIV, Antiretroviral, Prevention of mother-to-child transmission, Adverse drug reaction, Toxicity

Introduction Since the launch of the Global Programme to Eliminate Lymphatic Filariasis, more than 70% of the endemic countries have implemented mass drug administration (MDA) to interrupt disease transmission. The monitoring of filarial infection in sentinel populations, particularly schoolchildren, is recommended to assess the impact of MDA. A key issue is choosing the appropriate tools for these initial assessments (to define the best intervention) and for monitoring transmission. Methods This study compared the pre-MDA performance of five diagnostic methods, namely, thick film test, Knott's technique, filtration, Og4C3-ELISA, and the AD12-ICT card test, in schoolchildren from Brazil. Venous and capillary blood samples were collected between 11 pm and 1 am. The microfilarial loads were analyzed with a negative binomial regression, and the prevalence and associated 95% confidence intervals were estimated for all methods. The accuracies of the AD12-ICT card and Og4C3-ELISA tests were assessed against the combination of parasitological test results. Results A total of 805 schoolchildren were examined. The overall and stratified prevalence by age group and gender detected by Og4C3-ELISA and AD12-ICT were markedly higher than the prevalence estimated by the parasitological methods. The sensitivity of the AD12-ICT card and Og4C3-ELISA tests was approximately 100%, and the positive likelihood ratios were above 6. The specificity of the Og4C3-ELISA was higher than that of the AD12-ICT at different prevalence levels. Conclusions The ICT card test should be the recommended tool for monitoring school-age populations living in areas with ongoing or completed MDA.

INTRODUCTION: The Global Programme to Eliminate Lymphatic Filariasis was launched with the goal of eliminating this disease via the annual mass drug administration (MDA) of a single dose of antifilarial drugs. Adverse drug reactions following MDA are a major factor of poor treatment adherence in several countries. This study assessed the occurrence of adverse drug reactions (ADRs) following the first round of mass treatment in two communities treated with different dosages of diethylcarbamazine (DEC) in the City of Recife, Brazil. METHODS: Population-based cross-sectional surveys were conducted in a random sample of the population living in both communities (Areas I and II). The dose of DEC recommended by the WHO (6mg/kg) was calculated based on the individual's weight-for-age. In Area II, weight differences between the genders were also considered when determining dosage. Data were obtained through interviews conducted in the first 12 to 48h and on the 5th day after MDA during household visits. RESULTS: A total of 487 and 365 individuals were interviewed in Areas I and II, respectively. The prevalence of ADRs in Area I (23.6; 95%CI: 19.1-29.5) was higher than in Area II (16.2; 95%CI:11.9-21.5)(p=0.0078). The prevalence of ADRs among females was higher than in males in Area I (p=0.0021). In Area II, no significant difference between the genders was observed (p=0.1840). Age was not associated with ADRs in either area. CONCLUSIONS: Adjusting MDA dosage schedules according to weight-for-age and sex may be may contribute to reduce the occurrence of adverse drug reactions in the population.

Abstract Dengue cases have increased in younger age groups in Brazil. Maternal anti-dengue antibodies can have a protective effect in the first months of life, but their decline can increase the risk of severe dengue. A prospective birth cohort was established in 2011-2012 in the city of Recife, Pernambuco State, Brazil, to determine the incidence of serotype-specific dengue infection and the kinetics of transferred maternal anti-dengue antibodies in the first years of life. This article describes the design, methods and preliminary results of this cohort study. 354 children underwent clinical and laboratory monitoring for two years, with 15% losses to follow-up. The overall rate of new infections was approximately 10% in the first year of follow-up. Information on the force of serotype-specific dengue infection and the evaluation of transferred maternal antibodies can contribute to understanding dengue etiopathogenesis.

OBJETIVO: Avaliar os diferenciais da adequação das informações de nascimentos e óbitos do Ministério da Saúde para o cálculo da mortalidade infantil nos municípios do Estado de Pernambuco, 2006-2008. MÉTODOS: Estudo ecológico, cujas fontes de dados foram os sistemas de informação sobre nascidos vivos e mortalidade. Foram utilizados os indicadores: coeficiente de mortalidade geral padronizado por idade, desvio médio relativo do coeficiente de mortalidade geral, razão entre nascidos vivos informados e estimados, desvio médio relativo da taxa de natalidade e proporção de óbitos sem definição de causa básica. Estes indicadores foram agregados em três dimensões: mortalidade, natalidade e mal definidos. Utilizando critérios pré-estabelecidos, os municípios foram classificados como: informações vitais consolidadas, em fase de consolidação e não consolidadas. Os dados foram analisados através do programa Epiinfo e do Terraview para elaboração dos mapas. RESULTADOS: Dos 185 municípios do Estado, 141 (76,2%) foram classificados como informações vitais consolidadas, agregando aproximadamente 85% da população residente e 17 (9,2%) como não consolidadas, categoria na qual reside apenas 4,9% da população. Os municípios com 50.000 habitantes ou mais têm informações de melhor qualidade. CONCLUSÃO: O método utilizado mostrou-se potencial para classificar a qualidade das informações vitais em Pernambuco, identificando as desigualdades, que se constituem em desafios para o Estado, no sentido de possibilitar a análise destas informações a partir de dados diretos dos sistemas no âmbito municipal. Apenas dessa forma torna-se possível avaliar os investimentos realizados para a redução da mortalidade infantil em Pernambuco de forma realística.OBJECTIVE: To assess differentials in official birth and death data for estimating infant mortality. METHODS: An ecological study was conducted based on data obtained from birth and death information systems in the state of Pernambuco, northeastern Brazil, between 2006 and 2008. The following indicators were used: age-standardized mortality rate, relative mean deviation of mortality rate, ratio of reported to estimated live births, relative mean deviation of birth rate and proportion of deaths of unknown cause. These indicators were grouped into three dimensions: mortality, fertility and ill-defined causes. Based on predetermined criteria, municipalities were classified as follows: consolidated vital data; vital data in the consolidation phase; and non-consolidated data. The data were analyzed using EpiInfo and Terraview for map preparation. RESULTS: Of the 185 municipalities in the state of Pernambuco, 141 (76.2%) were classified as having consolidated vital data, accounting for about 85% of the state population, and 17 (9.2%) were classified as having non-consolidated data, accounting for only 4.9% of the population. Larger municipalities (50,000 inhabitants or more) showed better data quality. CONCLUSION: The approach studied proved itself valuable to assess the quality of vital information and identify inequalities in Pernambuco. Reduction of inequalities is a challenge in this state in the sense of enabling vital information to be analyzed directly from data systems at the local level. It will also allow assessing the effectiveness of initiatives to reduce infant mortality in Pernambuco.

Apesar dos meios para assistência adequada aos pacientes de dengue na rede de saúde, os índices de letalidade pela doença mantêm-se altos no Brasil. Visando a identificar implicações para ocorrência do óbito, este estudo avaliou a qualidade da assistência conforme grau de implantação das ações, qualidade técnico-científica da atenção e acesso aos serviços de saúde, em dois municípios do Nordeste do Brasil. Realizou-se pesquisa avaliativa, do tipo análise de implantação, tendo o óbito por dengue como evento sentinela da qualidade da assistência. Para avaliação do grau de implantação e qualidade da atenção, pontuaram-se os critérios das entrevistas e análise dos prontuários; para o acesso, procedeu-se à análise temática. Quanto à estrutura e ao processo, os serviços de saúde encontram-se parcialmente adequados (70%). Não foram encontradas barreiras geográficas e econômicas que justificassem a ocorrência dos óbitos. A qualidade técnico-científica não alcançou a adequação nos municípios (46% e 30%) e nos serviços avaliados, observando-se insuficiência no manejo clínico da dengue nos serviços de saúde.Despite the existing resources for adequate dengue patient care in the Brazilian healthcare system, the case-fatality rate for the disease is still high in the country. In order to identify factors associated with dengue-related death, this study evaluated quality of care according to the degree of implementation of specific measures, the technical and scientific quality of care, and access to health services in two municipalities (counties) in Northeast Brazil. An evaluative study of the implementation analysis type was performed, with death from dengue as the sentinel event for quality of care. To assess the degree of implementation and quality of care, the study scored the interview criteria and patient chart analysis; access was evaluated by thematic analysis. As for structure and process, the health services were found to be partially adequate (70%). No geographic or economic barriers were found to explain the occurrence of deaths. Technical and scientific quality failed to achieve adequate levels in the municipalities (46% and 30%) or in the specific services, and clinical management of dengue by the health services proved insufficient.

Para investigar fatores associados à cárie dentária na dentição decídua, realizou-se estudo de caso-controle aninhado a inquérito de prevalência em 1.690 pré-escolares de 18-36 meses e cinco anos de idade, assistidos pela Estratégia Saúde da Família no Recife, Pernambuco, Brasil, em 2006. Os casos foram crianças com ceo-d > 1 e os controles, com ceo-d = 0. As variáveis independentes foram analisadas em blocos sociodemográfico e ambiental, estrutura familiar, cuidados com a saúde bucal e uso de serviços. Estimou-se OR brutas e IC95%. Variáveis associadas ao desfecho com p < 0,20 em análises univariadas foram incluídas no modelo de regressão logística multivariado, com critério de permanência no modelo final p < 0,10. Maior número de moradores no domicílio, falta de abastecimento de água, tempo de moradia, escolaridade do cuidador, uso de pré-escola pública, procura por serviço de saúde bucal e padrão de consumo de açúcar foram fatores associados. As variáveis relacionadas ao contexto social foram os principais preditores de cárie, apontando para a necessidade de ações integradas de saúde comuns a outros agravos infantis.To investigate factors associated with dental caries in deciduous dentition, a nested case-control study was conducted in a prevalence survey of preschool children (n = 1,690) aged 18 to 36 months and 5 years of age, treated under the Family Health Program in Recife, Pernambuco State, Brazil, in 2006. Cases were children with dmft > 1 and controls with dmft = 0. The independent variables were analyzed in blocks: demographic, environmental, family structure, health care, and dental services use. OR and 95%CI were estimated. Variables associated with the outcome at p < 0.20 in the univariate analysis were included in a multivariate logistic regression model. The cutoff for remaining in the final model was p < 0.10. Larger households (more members), lack of running supply, time of residence, maternal (or caregiver's) schooling, attendance in public preschool, demand for dental services, and sugar intake patterns were associated factors. Variables related to social context were the main predictors of caries, thus highlighting the need for comprehensive measures to address other common childhood health problems.

OBJETIVO:Analisar o efeito de alimentos fortificados com ácido fólico na prevalência de defeitos de fechamento do tubo neural entre nascidos vivos. MÉTODOS: Estudo longitudinal de nascidos vivos do município de Recife (PE) entre 2000 e 2006. Os dados pesquisados foram obtidos do Sistema Nacional de Informações de Nascidos Vivos. Os defeitos de fechamento do tubo neural foram definidos de acordo com o Código Internacional de Doenças-10ª Revisão: anencefalia, encefalocele e espinha bífida. Compararam-se as prevalências nos períodos anterior (2000-2004) e posterior (2005-2006) ao período mandatório à fortificação. Analisou-se a tendência temporal das prevalências trimestrais de defeitos do fechamento do tubo neural pelos testes de Mann-Kendall e Sen's Slope. RESULTADOS: Não se identificou tendência de redução na ocorrência do desfecho (Teste de Mann-Kendall; p= 0,270; Sen's Slope =-0,008) no período estudado. Não houve diferença estatisticamente significativa entre as prevalências de defeitos do fechamento do tubo neural nos períodos anterior e posterior à fortificação dos alimentos com acido fólico de acordo com as características maternas. CONCLUSÕES: Embora não tenha sido observada redução dos defeitos do fechamento do tubo neural após o período mandatório de fortificação de alimentos com ácido fólico, os resultados encontrados não permitem descartar o seu benefício na prevenção desta malformação. São necessários estudos avaliando maior período e considerando o nível de consumo dos produtos fortificados pelas mulheres em idade fértil.OBJETIVO:Analizar el efecto de alimentos fortificados con ácido fólico en la prevalencia de defectos del cierre del tubo neural entre nacidos vivos. MÉTODOS: Estudio longitudinal de nacidos vivos del municipio de Recife (Noreste de Brasil), entre 2000 y 2006. Los datos pesquisados fueron obtenidos del Sistema Nacional de Informaciones de Nacidos Vivos. Los defectos del cierre del tubo neural fueron definidos de acuerdo con el Códigos Internacional de Enfermedades- 10ª Revisión: anencefalia, encefalocele y espina bífida. Se compararon las prevalencias en los períodos anterior (2000 - 2004) y posterior (2005-2006) al período obligatorio de fortificación. Se analizó la tendencia temporal de las prevalencias trimestrales de defectos del cierre del tubo neural por las pruebas de Mann-Kendall y Sen's Slope. RESULTADOS: No se identificó tendencia de reducción en la ocurrencia del hecho (Teste de Mann-Kendall); p= 0,270; Sen's Slope = - 0,008) en el período estudiado. No hubo diferencia estadísticamente significativa entre las prevalencias de defectos de cierre del tubo neural en los períodos anterior y posterior a la fortificación de los alimentos con ácido fólico de acuerdo con las características maternas. CONCLUSIONES: A pesar de que no haya sido observada reducción de los defectos de cierre del tubo neural posterior al período obligatorio de fortificación de alimentos con ácido fólico, los resultados encontrados no permiten descartar el beneficio del mismo en la prevención de esta malformación. Son necesarios estudios evaluando mayor período y considerando el nivel de consumo de los productos fortificados por las mujeres en edad fértil.OBJECTIVE:To analyze the effect of folic acid-fortified foods on the prevalence of neural tube defects in live newborns. METHODS: Longitudinal study with newborns from the city of Recife, Northeastern Brazil, between 2000 and 2006. Data analyzed were obtained from the Sistema Nacional de Informações de Nascidos Vivos (National Information System on Live Births). Neural tube defects were defined in accordance with the International Classification of Diseases, 10th revision (ICD-10): anencephaly, encephalocele, and spina bifida. Prevalences from the periods before (2000-2004) and after (2005-2006) the mandatory fortification period were compared. Time trend of three-month prevalences of neural tube defects were analyzed using Mann-Kendall test and Sen's Slope estimator. RESULTS: Tendency towards reduction in the occurrence of outcome (Mann-Kendall test; p= 0.270; Sen's Slope estimator =-0.008) was not identified in the period studied. The difference between prevalences of neural tube defects in the periods before and after food fortification with folic acid was not statistically significant, according to maternal characteristics. CONCLUSIONS: Even though reduction in neural tube defects after the period of mandatory food fortification with folic acid was not observed, results found do not enable its benefit to prevent malformations to be ruled out. Studies assessing longer periods and considering the level of consumption of fortified products by women of fertile age are necessary.

Significant advances were made in the diagnosis of filariasis in the 1990s with the emergence of three new alternative tools: ultrasound and tests to detect circulating antigen using two monoclonal antibodies, Og4C3 and AD12-ICT-card. This study aimed to identify which of these methods is the most sensitive for diagnosis of infection. A total of 256 individuals, all male and carrying microfilariae (1-15,679 MF/mL), diagnosed by nocturnal venous blood samples, were tested by all three techniques. The tests for circulating filarial antigen concurred 100% and correctly identified 246/256 (96.69%) of the positive individuals, while ultrasound detected only 186/256 (73.44%). Of the circulating antigen tests, ICT-card was the most convenient method for identification of Wuchereria bancrofti carriers. It was easy to perform, practical and quick.

Avaliou-se a confiabilidade das informações sobre defeitos congênitos contidas nas declarações de nascido vivo do Sistema de Informações sobre Nascidos Vivos (SINASC) no Município do Rio de Janeiro, Brasil, no ano de 2004 comparando-as com os prontuários hospitalares destas crianças e de suas mães na internação para o parto. Após a seleção de 24 maternidades do SUS, os tipos de defeitos congênitos constantes nos prontuários foram transcritos em formulários de coleta próprios, codificados com base na CID-10 e comparados com os arquivos do SINASC. Verificou-se uma maior freqüência de defeitos congênitos dos sistemas osteomuscular e nervoso central e percentual de concordância acima de 50% nos aparelhos digestivo, urinário e osteomuscular, órgãos genitais e de anomalias cromossômicas. O kappa ajustado pela prevalência variou conforme as análises para 2 ou 3 dígitos da CID-10, com melhores resultados nos aparelhos osteomuscular, genito-urinário, digestivo e as anomalias cromossômicas e os piores nos sistemas nervoso central e cárdio-circulatório, malformações congênitas da face, olhos pescoço e orelhas e fendas lábio-palatinas. Os resultados encontrados são insatisfatórios e apontam para a necessidade de qualificação do pessoal envolvido no preenchimento das declarações assim como a padronização da codificação dos defeitos congênitos.This study assessed the reliability of birth certificate data related to birth defects in Brazil's Live Birth Information System (SINASC). We selected 24 maternity hospitals in the Unified National Health System (SUS) and compared the reports of birth defects from birth certificates with medical records of mothers and live born infants in the city of Rio de Janeiro for the year 2004. After transposing the data to a specific form, the birth defects were coded by types and organ systems and compared to the SINASC data. The most commonly affected organs involved the central nervous and musculoskeletal systems. Agreement was more than 50% for the digestive, genitourinary, and musculoskeletal systems and chromosomal anomalies. Prevalence-adjusted kappa varied according to 2 or 3-digit ICD-10 analysis, with better results for the musculoskeletal, digestive, and genitourinary systems and congenital anomalies, and worse for the central nervous and cardio-circulatory systems, eye, neck, and ear malformations, and cleft lip and palate. The results were unsatisfactory, suggesting the need for more investments to train the persons responsible for completing birth certificates in maternity hospitals and develop a model for coding birth defects on these documents.

Avaliou-se a ocorrência de defeitos congênitos em nascidos vivos no Município do Rio de Janeiro, Brasil, com base no Sistema de Informações sobre Nascidos Vivos (SINASC), no período de 1º de janeiro de 2000 a 31 de dezembro de 2004. Através de um estudo seccional e descritivo, estudaram-se as variáveis relativas aos defeitos congênitos (presença e aparelho ou sistema acometido), aos serviços de saúde, às mães, às gestações, aos recém-natos e aos partos. Constatou-se uma prevalência de defeitos congênitos de 83/10 mil nascidos vivos. Os sistemas orgânicos mais afetados foram o osteomuscular, nervoso central, genital, as fendas lábio-palatinas e as anomalias cromossômicas. A maioria dos casos nasceu nas maternidades municipais e na rede privada, e maior prevalência de defeitos congênitos ocorreu no Instituto Fernandes Figueira da Fundação Oswaldo Cruz. Os defeitos congênitos foram mais prevalentes entre os filhos de mulheres mais velhas e menos instruídas. O percentual de casos ignorados foi alto, chegando a 21% em algumas maternidades. Uma maior divulgação das informações do SINASC sobre defeitos congênitos deveria ser estimulada. Estudos de confiabilidade são recomendados para melhor aproveitamento das informações.To evaluate the occurrence of birth defects in the city of Rio de Janeiro, Brazil, using the Live Birth Information System (SINASC), we performed a cross-sectional study on all live newborns with birth defects from January 1, 2000, to December 31, 2004. The variables referred to birth defects (presence and system affected), type of health service, mothers, gestations, live births, and deliveries. Prevalence of birth defects was 83/10,000 live births. The most frequent birth defects involved the musculoskeletal system, central nervous system, cleft lip and palate, and chromosomal anomalies. The majority of cases were born in public (municipal) and private maternity hospitals, with the highest prevalence in the Fernandes Figueira Insitute, Oswaldo Cruz Foundation. Older women and those with less schooling had more live born infants with birth defects. The proportion of reports with missing information was high, reaching 21% in some institutions. Wider dissemination of SINASC data on birth defects should be encouraged. Reliability studies are recommended for better use of these reports.

OBJETIVO: Avaliar o consumo alimentar durante a gestação e pós-parto, segundo cor da pele. MÉTODOS: Estudo longitudinal prospectivo que incluiu 467 mulheres entre 15 e 45 anos no período pós-parto, no município do Rio de Janeiro, entre 1999 e 2001. Foi aplicado um questionário de freqüência de consumo de alimentos aos 15 dias pós-parto (consumo referente ao período da gestação) e aos seis meses (consumo referente ao período pós-parto). Foi utilizada análise de covariância para analisar diferenças no consumo alimentar, segundo cor da pele, controlada pela escolaridade. RESULTADOS: Durante a gestação, pretas e pardas apresentaram consumo de energia 13,4% e 9,1% (p=0,009 e p=0,028) e consumo de carboidrato 15,1% e 10,5% maior que brancas (p=0,005 e p=0,014), respectivamente. Mulheres pretas e brancas apresentaram consumo energético 34% e 20% acima das recomendações nutricionais, respectivamente (p=0,035). Durante o período pós-parto, as pretas apresentaram consumo de energia 7,7% maior e consumo de lipídios 14,8% maior que as brancas; consumo de ácidos graxos saturados 23,8% maior que brancas (p=0,003) e 13% maior que pardas (p=0,046). A adequação de consumo de lipídios e ácidos graxos saturados foi maior em pretas que em brancas (p=0,024 e p=0,011, respectivamente). CONCLUSÕES: Os resultados mostram ser necessário revisar estratégias de intervenção nutricional no pré-natal e implementar assistência nutricional no pós-parto, para ajustar o consumo alimentar a níveis adequados, considerando as diferenças por cor/raça identificadas.OBJECTIVE: To assess dietary intake during pregnancy and postpartum according to skin color. METHODS: A longitudinal prospective study was carried out comprising 467 postpartum women aged between 15-45 years in the city of Rio de Janeiro, Southeastern Brazil, in 1999-2001. A food frequency questionnaire was administered at two weeks postpartum (intake covering the pregnancy period) and at six months postpartum (intake covering the postpartum period). Analysis of covariance was performed to evaluate differences in food intake among skin color groups, adjusted for educational level. RESULTS: During pregnancy, black and mulatto women had 13.4% and 9.1% higher energy intake (p=0.009 and p=0.028) and 15.1% and 10.5% higher carbohydrate intake (p=0.005 and p=0.014) than white women, respectively. Energy intake of black and white women exceeded the nutritional recommendations by 34% and 20%, respectively (p=0.035). During the postpartum period, black women had 7.7% higher energy intake (p=0.030) and 14.8% higher lipid intake (p=0.008) than white women, as well as 23.8% and 13% higher saturated fatty acids intake than white (p = 0.003) and mulatto (p = 0.046) women, respectively. The adequacy of lipid and saturated fatty acids intake was higher in black (p=0.024) than white women (p=0.011). CONCLUSIONS: The study suggests the need to revise nutritional interventions strategies in the prenatal period, and to implement nutritional guidance programs during the postpartum period in order to adjust food intake to adequate levels, taking into consideration racial differences identified.

OBJECTIVE: To describe trends in sociodemographic, immunological and virological profiles and interventions to decrease the risk of mother-to-child HIV transmission. METHODS: Retrospective cohort study conducted at a tertiary institution in Rio de Janeiro, Brazil from January 1996 to December 2004. Analysis was performed by stratification in three time periods: 1996-1998 (P1), 1999-2001 (P2) and 2002-2004 (P3). RESULTS: In 9 years, 622 pregnancies occurred. Complications included: maternal mortality 0.3%, stillbirths 2.5%, miscarriages 0.6%, neonatal mortality 1.1%, prematurity 9.9%, low birth weight (LBW) 16.5%, congenital malformations 2.2%. The number of HIV-infected pregnant patients grew threefold over time reflecting increased prevalence of disease and patient identification. HIV diagnosis before pregnancy increased from 30% in P1 to 45% in P3. The proportion of pregnant women receiving highly active antiretroviral therapy increased from none (P1) to 88% (P3) with a significant trend towards women delivering at undetectable viral loads in later years despite a higher frequency of advanced disease. Scheduled cesarean deliveries increased from 35% in P1 to 48% in P3. Perinatal transmission rates were 2.4% with a decline from 3.5% in P1 to 1.6% in P3. Neonatal outcomes tended to remain constant or improve with time. A slight rise in LBW and congenital malformations were observed. CONCLUSIONS: During the observational period, HIV+ pregnant women presented with more advanced disease and lower socio-economic status. However, improved management of HIV-infected patients (associated with increased identification and increased availability of treatment) resulted into very low transmission rates similar to those of developed countries with overall improvement of patient outcomes.OBJETIVOS: Descrever as tendências temporais nas características sociodemográficas, imunológicas e virológicas e as das condutas utilizadas para reduzir o risco da transmissão mãe-filho do HIV. MÉTODOS: Estudo de coorte retrospectivo em uma instituição de saúde terciária no Rio de Janeiro de janeiro de 1996 a dezembro de 2004. A análise utilizou a estratificação em três períodos de tempo: 1996-1998 (P1), 1999-2001 (P2) e 2002-2004 (P3). RESULTADOS: Em 9 anos, 622 gestações foram acompanhadas. As complicações foram: mortalidade materna 0,3%, natimortos 2,5%, abortos 0,6%, mortalidade neonatal 1,1%, prematuridade 9,9%, baixo peso ao nascer (BPN) 16,5%, malformações congênitas 2,2%. O número de gestantes HIV positivo triplicou ao longo do tempo, refletindo o aumento da prevalência da doença e a melhor identificação das pacientes. O diagnóstico da infecção pelo HIV antes da gestação aumentou de 30% em P1 para 45% em P3. A proporção de gestantes recebendo o tratamento combinado potente aumentou de zero em P1 para 88% em P3 com uma tendência significativa a ter uma carga viral abaixo do limite de detecção no parto nos últimos anos apesar de uma maior proporção de pacientes com doença mais avançada. O índice de cesarianas eletivas aumentou de 35% em P1 para 48% em P3. A taxa de transmissão perinatal global foi de 2,4% caindo de 3,5% em P1 para 1,6% em P3. Os desfechos neonatais tenderam a permanecer constantes ou a melhorar ao longo do tempo. Um discreto aumento dos índices de BPN e de malformações congênitas foi observado. CONCLUSÕES: Ao longo do período de estudo aumentou a proporção de gestantes HIV positivo com doença mais avançada e com padrão socioeconômico mais baixo. Por outro lado, a melhora da abordagem terapêutica dos pacientes infectados pelo HIV, associada a uma maior detecção de casos e maior acesso ao tratamento, resultou em uma redução da taxa de transmissão igualando-se à observada em países desenvolvidos com melhora concomitante de outros desfechos.

Neste estudo, descreveram-se as características dos 14.419 pacientes com insuficiência renal crônica tratados por hemodiálise no Estado do Rio de Janeiro, Brasil, e analisou-se o tempo até a primeira realização do transplante no período de 1998 a 2002. Técnicas de análise de sobrevida como a análise não paramétrica de Kaplan-Meier e a modelagem semiparamétrica com o modelo de riscos proporcionais de Cox foram utilizadas. Além do modelo de sobrevida para transplante, o tempo até o óbito foi estimado para a comparação das estimativas dos dois modelos. Os resultados mostraram que, no período estudado, apenas 6,3% dos pacientes foram transplantados, 32,4% foram indicados e 6,3% inscritos na lista de espera. Observa-se que a probabilidade de transplante dos pacientes indicados, inscritos para o transplante e os que estão em uma faixa etária reduzida é maior. A diabetes mellitus possui um efeito redutor de 35% no risco de realização de transplante. Todas as estimativas apresentaram direções contrárias às obtidas pelo modelo de sobrevida para óbito.This study analyzes the characteristics of 14,419 chronic renal failure patients treated with hemodialysis and time to first kidney transplantation in the State of Rio de Janeiro, Brazil, from 1998 to 2002. Survival analysis methods were used, such as the Kaplan-Meier non-parametric method and the semi-parametric method with the Cox proportional hazards model. Besides the survival model for transplantation, time to death was analyzed to compare the two models' estimates. During the period studied, only 6.3% of patients received transplants, 32.4% were referred for transplantation, and 6.3% were included on the waiting list. Odds of transplantation were greater for those who had been referred, those on the waiting list, and younger patients. Diabetes mellitus reduced the probability of conducting transplantation by 35%. All the estimates showed directions opposite to those obtained for the mortality survival model.

O trabalho avalia a qualidade da informação do Sistema de Informações sobre Nascidos Vivos (SINASC) quanto à clareza metodológica da documentação, completitude do preenchimento e consistência para o país, grandes regiões e Unidades da Federação no ano 2002. Adicionalmente, correlaciona-se a completitude com indicadores de pobreza, desigualdade e recursos humanos. As variáveis analisadas são: raça/cor do recém-nascido, instrução materna, estado civil materno, ocupação materna, idade materna, consulta pré-natal, filhos nascidos vivos, filhos nascidos mortos e peso do bebê ao nascer. Mostrou-se que o SINASC possui boa completitude de preenchimento e consistência da informação na maioria das variáveis; porém, observaram-se sérios problemas de qualidade nas variáveis sobre filhos anteriores e ocupação. Quanto à raça, encontraram-se tanto problemas metodológicos de definição da variável como incompletitude do preenchimento no Distrito Federal, São Paulo, Bahia e Sergipe, Brasil. Por intermédio da análise estatística, confirmou-se a relação significativa entre completitude e indicadores de pobreza e desigualdade. Espera-se que melhorias da qualidade da informação do SINASC possam contribuir para que esse sistema seja uma robusta fonte de dados epidemiológicos que permita identificar fatores de risco e condicionantes sócio-econômicos.This study evaluates the quality of data in the Brazilian Live Births Information System (SINASC), focusing on the methodological clarity of documentation and adequate data completeness and consistency at the national, regional, and State levels in 2002. The variables analyzed were: skin color/race of newborn, maternal schooling, maternal marital status, maternal occupation, maternal age, prenatal visits, live births, stillbirths, and birth weight. For most of the variables, SINASC shows good data completeness and consistency, but there were serious problems with the quality of data on previous children and maternal occupation. Related to race, there were some methodological problems in the definition and incomplete filling-in for the Federal District (Brasília) and the States of São Paulo, Bahia, and Sergipe. Statistical analysis confirmed a significant association between data completeness and indicators of poverty and inequality. The study showed that improvements in SINASC data quality could make this system a good epidemiological source for identifying risk factors and socioeconomic conditioning factors.

BACKGROUND:Dengue is an increasing public health concern in Brazil. There is a need for an updated evaluation of the economic impact of dengue within the country. We undertook this multicenter study to evaluate the economic burden of dengue in Brazil. METHODS:We estimated the economic burden of dengue in Brazil for the years 2009 to 2013 and for the epidemic season of August 2012- September 2013. We conducted a multicenter cohort study across four endemic regions: Midwest, Goiania; Southeast, Belo Horizonte and Rio de Janeiro; Northeast: Teresina and Recife; and the North, Belem. Ambulatory or hospitalized cases with suspected or laboratory-confirmed dengue treated in both the private and public sectors were recruited. Interviews were scheduled for the convalescent period to ascertain characteristics of the dengue episode, date of first symptoms/signs and recovery, use of medical services, work/school absence, household spending (out-of-pocket expense) and income lost using a questionnaire developed for a previous cost study. We also extracted data from the patients' medical records for hospitalized cases. Overall costs per case and cumulative costs were calculated from the public payer and societal perspectives. National cost estimations took into account cases reported in the official notification system (SINAN) with adjustment for underreporting of cases. We applied a probabilistic sensitivity analysis using Monte Carlo simulations with 90% certainty levels (CL). RESULTS:We screened 2,223 cases, of which 2,035 (91.5%) symptomatic dengue cases were included in our study. The estimated cost for dengue for the epidemic season (2012-2013) in the societal perspective was US$ 468 million (90% CL: 349-590) or US$ 1,212 million (90% CL: 904-1,526) after adjusting for under-reporting. Considering the time series of dengue (2009-2013) the estimated cost of dengue varied from US$ 371 million (2009) to US$ 1,228 million (2013). CONCLUSIONS:The economic burden associated with dengue in Brazil is substantial with large variations in reported cases and consequently costs reflecting the dynamic of dengue transmission.

OBJETIVO: Analisar as desigualdades sociodemográficas, na assistência pré-natal e ao parto e suas conseqüências sobre o peso ao nascer. MÉTODOS: Estudo realizado em amostra de 10.072 puérperas atendidas em maternidades públicas, conveniadas com o Sistema Único de Saúde, e particulares do Município do Rio de Janeiro, no período de 1999-2001. Para verificar a associação entre peso ao nascer e características maternas, sociodemográficas, biológicas e da assistência pré-natal (índice de Kotelchuck modificado), realizaram-se regressões lineares múltiplas, estratificando as puérperas segundo nível de instrução. Foi utilizada a técnica de bootstrap com intervalos de confiança acurados para as estimativas dos efeitos. RESULTADOS: Na análise bivariada, para quase todas as variáveis estudadas, as médias de peso ao nascer foram menores entre as mães de escolaridade mais baixa. Na análise da regressão múltipla para o grupo de baixa escolaridade, o peso ao nascer associou-se diretamente com o índice de Kotelchuck modificado e a idade gestacional, e inversamente com as variáveis cor da pele preta, hábito de fumar e a experiência de filhos prematuros anteriores. Idade materna e paridade tiveram comportamentos distintos nos extremos e na faixa central dos dados. No grupo de maior escolaridade somente a paridade, a idade gestacional e o índice de Kotelchuck modificado foram significativos e se associaram diretamente com o peso ao nascer. Verificou-se o papel protetor da assistência pré-natal, assim como o efeito negativo do hábito de fumar independente do nível de escolaridade das mães. CONCLUSÕES: As variáveis que explicaram o peso ao nascer dos neonatos de mães com elevada escolaridade foram de natureza biológica, em contraste com os determinantes sociais encontrados no grupo de baixa escolaridade.OBJECTIVE: To analyze sociodemographic inequalities in prenatal and childbirth care and their consequences on birth weight. METHODS: The study was based on a sample of 10,072 postpartum women treated at public (those outsourced by the National Health System) and private maternity hospitals in Rio de Janeiro, Brazil, from 1999 to 2001. To test the association between birth weight and maternal sociodemographic and biological characteristics and prenatal care (modified Kotelchuck index), postpartum women were stratified by level of schooling and two multiple linear regressions were performed. The bootstrap technique was used in addition to accurate confidence intervals for the estimated effects. RESULTS: For nearly all of the variables analyzed in the bivariate analysis, birth weight was lower among children of mothers with low schooling. In the multivariate analysis, among women with low schooling, there was a direct association between birth weight and the modified Kotelchuck index and gestational age. The variables black skin color, smoking, and history of premature birth were negatively associated with birth weight, while maternal age and parity showed distinct behaviors from the central range of data at the extremes. In the group with high schooling, only parity, gestational age, and modified Kotelchuck index were significant and directly associated with birth weight. The protective effect of prenatal care was observed, as well as the negative effect of smoking, regardless of the mother's level of schooling. CONCLUSIONS: The variables associated with neonates' birth weight of mothers with high schooling in Rio de Janeiro were biological, in contrast to the social determinants in the group with low schooling.

Gender differences in susceptibility to infectious diseases have been observed in various studies. A survey was performed in a bancroftian filariasis endemic area in the city of Olinda, Brazil. All residents aged 5 years or older were examined by thick blood film. People aged 9 to 16 years were interviewed and also tested for filarial antigenaemia. Data were analyzed by contingency table methods and regression models. The risk of microfilaraemia for males was significantly higher. Among those aged 9 to 16 years, the analysis of gender and filariasis by age showed that boys from 15 to 16 years had a higher risk of infection than girls. No association was found between menarche and filariasis in girls. The data suggest that variations between gender in filariasis could result, at least in part, from an increase in susceptibility of men. This epidemiologic feature needs to be considered while formulating elimination plans.

OBJETIVO: Analisar as desigualdades sociais e no acesso e utilização dos serviços de saúde em relação à cor da pele em amostra representativa de puérperas que demandaram atenção hospitalar ao parto. MÉTODOS: Trata-se de estudo transversal, realizado no Município do Rio de Janeiro, no qual foram amostradas 9.633 puérperas, sendo 5.002 brancas (51,9%), 2.796 pardas (29,0%) e 1.835 negras (19,0%), oriundas de maternidades públicas, conveniadas com o Sistema Único de Saúde e particulares no período de 1999 a 2001. Os dados foram coletados de prontuários médicos e por entrevistas com as mães no pós-parto imediato, aplicando questionários padronizados. Foram utilizados os testes de chi² para analisar a homogeneidade das proporções e t de Student para comparação de médias. A análise foi estratificada segundo o grau de instrução materna. RESULTADOS: Observou-se persistente situação desfavorável das mulheres de pele preta e parda em relação às brancas. Nas mulheres pretas e pardas são maiores as proporções de puérperas adolescentes, com baixa escolaridade, sem trabalho remunerado e vivendo sem companheiro. Sofrer agressão física, fumar, tentar interromper a gravidez e peregrinar em busca de atenção médica foram mais freqüentes nas negras seguidas das pardas e das brancas com baixa escolaridade. O grupo de elevado nível de escolaridade tem melhores indicadores, mas repete o mesmo padrão. Esse gradiente se mantém, em sentido inverso, quanto à satisfação com a assistência prestada no pré-natal e no parto. Constata-se a existência de duas formas de discriminação, por nível educacional e cor da pele. CONCLUSÕES: Verificaram-se dois níveis de discriminação, a educacional e a racial, que perpassam a esfera da atenção oferecida pelos serviços de saúde à população de puérperas do Município do Rio de Janeiro.

O artigo discute a relação entre a produção científica sobre a ocorrência da filariose bancroftiana no Brasil e o processo de formulação e implementação da política de saúde voltada ao seu controle. Para tanto, realiza uma revisão da produção do conhecimento e das políticas específicas, no período compreendido desde a criação do Programa de Combate à Filariose, em meados do século passado, até a criação do SUS, no marco da descentralização do controle das endemias. Centrando suas observações empíricas na ambiência da cidade do Recife, espaço urbano no qual ainda prevalece a filariose, ressalta os processos institucionais e destaca o papel dos distintos atores neles envolvidos. Partindo da hipótese de que se até à primeira metade do século vinte faltavam o conhecimento científico e o desenvolvimento tecnológico para o controle do problema, a seguir, quando esses avanços são disponibilizados, outros requerimentos, agora do campo da política, irão se impor, atuando como determinantes da persistência da endemia na cidade.This article discusses the relationship between the production of scientific knowledge on filariasis in Brazil and health policy-making and implementation related to control of the disease. The study presents a review of scientific output on filariasis from the creation of the Program to Combat Filariasis in the mid-20th century until the creation of the Unified National Health System (SUS) within the framework of decentralized control of endemic diseases in the country. The focus on empirical observations in Recife, a city where filariasis is present, highlights the relevant institutional processes and the role of various players. The hypothesis is that in the first half of the 20th century there was a lack of scientific knowledge and technological development to control the problem, but that after these advances were obtained, new requirements of a political nature came into play and acted as determinants for persistence of the endemic in the city.

O conceito de espaço socialmente organizado, subsidiado por novas técnicas de análise, mapeamento e espacialização da ocorrência de eventos, tem orientado desenvolvimentos metodológicos inovadores no campo das intervenções de saúde pública. Este estudo teve por objetivo avaliar a utilização de um indicador sócio-ambiental, construído através da metodologia de aplicação de escores, na estratificação do Município de Olinda, Pernambuco, em áreas com diferentes riscos de transmissão da filariose bancroftiana. Procedeu-se ao mapeamento das áreas, localização dos domicílios amostrados e identificação de todos os moradores com idade entre 5 e 65 anos para realização do inquérito parasitológico. Dentre as 3.232 pessoas examinadas, 42 foram positivas, obtendo-se prevalência de microfilaremia de 1,3%. A análise estatística global da distribuição dos casos mostrou evidências de agregação espacial. Nos dois estratos de mais alto risco de transmissão residiam 85,7% dos positivos. A alta sensibilidade do indicador proposto justifica a sua utilização para o planejamento e execução de intervenções ao predizer o local de ocorrência da maioria dos casos de filariose.The concept of a "socially organized space" supported by new analytical techniques and mapping of health events has guided innovative methodological developments in public health interventions. This study aimed to evaluate a social/environmental indicator constructed with a scoring methodology to stratify areas in the city of Olinda by different levels of risk for Bancroftian filariasis transmission. The study mapped areas and the location of sample households and identified all residents ages 5 to 65 years as part of the parasitological survey. Among the 3,232 individuals who had blood samples taken, 42 were microfilaremic (1.3% prevalence). Global statistical analysis of filarial case distribution has suggested spatial clustering. Some 85.7% of positive individuals resided in the two strata with the highest transmission risk. The high sensitivity of the proposed indicator for predicting the places where the vast majority of filariasis cases occurred justifies its use in planning and implementing interventions.

Aedes aegypti has developed evolution-driven adaptations for surviving in the domestic human habitat. Several trap models have been designed considering these strategies and tested for monitoring this efficient vector of Dengue. Here, we report a real-scale evaluation of a system for monitoring and controlling mosquito populations based on egg sampling coupled with geographic information systems technology. The SMCP-Aedes, a system based on open technology and open data standards, was set up from March/2008 to October/2011 as a pilot trial in two sites of Pernambuco -Brazil: Ipojuca (10,000 residents) and Santa Cruz (83,000), in a joint effort of health authorities and staff, and a network of scientists providing scientific support. A widespread infestation by Aedes was found in both sites in 2008-2009, with 96.8%-100% trap positivity. Egg densities were markedly higher in SCC than in Ipojuca. A 90% decrease in egg density was recorded in SCC after two years of sustained control pressure imposed by suppression of >7,500,000 eggs and >3,200 adults, plus larval control by adding fishes to cisterns. In Ipojuca, 1.1 million mosquito eggs were suppressed and a 77% reduction in egg density was achieved. This study aimed at assessing the applicability of a system using GIS and spatial statistic analysis tools for quantitative assessment of mosquito populations. It also provided useful information on the requirements for reducing well-established mosquito populations. Results from two cities led us to conclude that the success in markedly reducing an Aedes population required the appropriate choice of control measures for sustained mass elimination guided by a user-friendly mosquito surveillance system. The system was able to support interventional decisions and to assess the program's success. Additionally, it created a stimulating environment for health staff and residents, which had a positive impact on their commitment to the dengue control program.

BACKGROUND: Dengue is a disease of great complexity, due to interactions between humans, mosquitoes and various virus serotypes as well as efficient vector survival strategies. Thus, understanding the factors influencing the persistence of the disease has been a challenge for scientists and policy makers. The aim of this study is to investigate the influence of various factors related to humans and vectors in the maintenance of viral transmission during extended periods. METHODOLOGY/PRINCIPAL FINDINGS: We developed a stochastic cellular automata model to simulate the spread of dengue fever in a dense community. Each cell can correspond to a built area, and human and mosquito populations are individually monitored during the simulations. Human mobility and renewal, as well as vector infestation, are taken into consideration. To investigate the factors influencing the maintenance of viral circulation, two sets of simulations were performed: (1(st)) varying human renewal rates and human population sizes and (2(nd)) varying the house index (fraction of infested buildings) and vector per human ratio. We found that viral transmission is inhibited with the combination of small human populations with low renewal rates. It is also shown that maintenance of viral circulation for extended periods is possible at low values of house index. Based on the results of the model and on a study conducted in the city of Recife, Brazil, which associates vector infestation with Aedes aegytpi egg counts, we question the current methodology used in calculating the house index, based on larval survey. CONCLUSIONS/SIGNIFICANCE: This study contributed to a better understanding of the dynamics of dengue subsistence. Using basic concepts of metapopulations, we concluded that low infestation rates in a few neighborhoods ensure the persistence of dengue in large cities and suggested that better strategies should be implemented to obtain measures of house index values, in order to improve the dengue monitoring and control system.