Post-therapeutic cure criterion in chronic Chagas disease using Trypanosoma cruzi chimeric proteins.

Chagas disease (CD) is a neglected disease caused by Trypanosoma cruzi Chagas, 1909. Causative treatment can be achieved with two drugs: benznidazole or Nifurtimox. There are some gaps that hinder progress in eradicating the disease. There is no test that can efficiently assess cure control after treatment. Currently, the decline in anti-T. cruzi antibody titres is assessed with conventional serological tests, which can take years. However, the search for new markers of cure must continue to fill this gap. The present study aimed to evaluate the decline in serological titres using chimeric proteins after treatment with benznidazole in chronic patients diagnosed with CD. It was a prospective cross-sectional cohort study between 2000 and 2004 of T. cruzi-positive participants from the Añatuya region (Argentina) treated with benznidazole. Serum samples from ten patients were collected before treatment (day zero) and after the end of treatment (2, 3, 6, 12, 24 and 36 months). For the detection of anti-T. cruzi antibodies, an indirect ELISA was performed using two chimeric recombinant proteins (IBMP-8.1 and IBMP-8.4) as antigens. The changes in reactivity index within the groups before and after treatment were evaluated using the Friedman test. All participants experienced a decrease in serological titres after treatment with benznidazole, especially IBMP-8.1. However, due to the small number of samples and the short follow-up period, it is premature to conclude that this molecule serves as a criterion for sustained cure. Further studies are needed to validate tests based on these or other biomarkers to demonstrate parasitological cure.

The impact of implementing the 10-valent pneumococcal conjugate vaccine on hospitalizations for pneumonia among children.

Pneumonia is a major cause of morbidity and mortality in children, with pneumococcus as the main etiologic agent. In Brazil, the 10-valent pneumococcal conjugate vaccine (PCV-10) was introduced into the childhood immunization schedule in 2010. The aim of this study was to assess the impact caused by implementing PCV-10 on the hospitalizations of children with pneumonia, between 2005 and 2015, in the state of Pernambuco, Brazil. An ecological time series study and a forecasting analysis were conducted. A comparison was made between the hospitalizations of children aged between seven months and four years due to pneumonia in the Brazilian Unified Health System, in the 5 years before (2005-2009) and after (2011-2015) implementation of PCV-10. Descriptive analysis included absolute and relative values, means and rates of hospitalization. The chi-square test was used to compare the annual incidence of hospitalizations and the t-Student test to compare the five-year mean values. For the temporal modeling of hospitalizations, an autoregressive integrated moving average was used, adjusted with seasonal-SARIMA (Box-Jenkins methodology), with a prediction of the monthly number of hospitalizations for 2011-2015. The predicted and observed values for 2011-2015 were then compared. The number of hospitalizations after implementing PCV-10 was reduced by 24.5 %. The monthly average of hospitalizations dropped from 681 (2005-2009) to 514 (2011-2015). The hospitalization rate dropped from 56.1 per thousand live births in the five-year period prior to PCV-10 to 43.4 in the following five-year period (a 22.7% reduction). Comparing the values predicted by the SARIMA model for a scenario without PCV-10 in the second five-year period, with those reported after implementing PCV-10, the estimated number of prevented hospitalizations was 8,682 in the five years following the introduction of the vaccine. In conclusion, in the five years following implementation of PCV-10, hospitalizations of children with pneumonia in Pernambuco decrease by 22%.

Impact of the COVID-19 pandemic on the mental health of frontline healthcare workers in a highly affected region in Brazil.

BACKGROUND: The COVID-19 pandemic had a major impact on the mental health of healthcare workers (HCWs), especially in low and middle-income countries, which had to face additional political, social, and economic challenges. We thus aimed to assess the prevalence of mental health outcomes and the associated factors in HCWs treating COVID-19 patients in one of the most affected regions in Brazil. METHODS: We used the Respondent-Driven Sampling method to assess the risks of COVID-19 infection and symptoms of mental disorders in nurses, nursing technicians, and physicians who worked on the frontline in the metropolitan region of Recife. 865 healthcare workers completed a survey regarding sociodemographic data, work-related risks, and symptoms of mental disorders - SRQ-20 for common mental disorders (CMD); AUDIT-C for problematic alcohol use; GAD-7 for anxiety; PHQ-9 for depression; PCL-5 for post-traumatic stress disorder (PTSD). Gile's successive sampling estimator was used to produce the weighted estimates by professional category. A Poisson regression model with robust variance was used to analyze factors associated with a positive screening for CMD. We will present the results of a cross-sectional analysis of the mental health outcomes after the first peak of COVID-19 - from August 2020 to February 2021. RESULTS: The prevalence ratios for a positive screening for CMD were 34.9% (95% CI: 27.8-41.9) in nurses, 28.6% (95% CI: 21.3-36.0) in physicians, and 26.6% (95% CI: 16.8-36.5) in nursing technicians. Nurses presented a higher prevalence of depressive symptoms (23%). Positive screening for problematic alcohol use (10.5 to14.0%), anxiety (10.4 to 13.3%), and PTSD (3.3 to 4.4%) were similar between the professional categories. The main factors associated with CMD in nurses and physicians were related to an intrinsic susceptibility to mental illness, such as previous or family history of psychiatric disorder, and female sex. Among nurse technicians, work-related factors, such as accidents with biological material, presented the strongest association with CMD. CONCLUSION: The mental health of HCWs fighting COVID-19 in Recife was severely affected. It is crucial that healthcare services provide adequate working conditions and psychological support, investing in programs to promote and protect HCWs mental health.

Risk of adverse outcomes in offspring with RT-PCR confirmed prenatal Zika virus exposure: An individual participant data meta-analysis of 13 cohorts in the Zika Brazilian Cohorts Consortium.

Background: Knowledge regarding the risks associated with Zika virus (ZIKV) infections in pregnancy has relied on individual studies with relatively small sample sizes and variable risk estimates of adverse outcomes, or on surveillance or routinely collected data. Using data from the Zika Brazilian Cohorts Consortium, this study aims, to estimate the risk of adverse outcomes among offspring of women with RT-PCR-confirmed ZIKV infection during pregnancy and to explore heterogeneity between studies. Methods: We performed an individual participant data meta-analysis of the offspring of 1548 pregnant women from 13 studies, using one and two-stage meta-analyses to estimate the absolute risks. Findings: Of the 1548 ZIKV-exposed pregnancies, the risk of miscarriage was 0.9%, while the risk of stillbirth was 0.3%. Among the pregnancies with liveborn children, the risk of prematurity was 10,5%, the risk of low birth weight was 7.7, and the risk of small for gestational age (SGA) was 16.2%. For other abnormalities, the absolute risks were: 2.6% for microcephaly at birth or first evaluation, 4.0% for microcephaly at any time during follow-up, 7.9% for neuroimaging abnormalities, 18.7% for functional neurological abnormalities, 4.0% for ophthalmic abnormalities, 6.4% for auditory abnormalities, 0.6% for arthrogryposis, and 1.5% for dysphagia. This risk was similar in all sites studied and in different socioeconomic conditions, indicating that there are not likely to be other factors modifying this association. Interpretation: This study based on prospectively collected data generates the most robust evidence to date on the risks of congenital ZIKV infections over the early life course. Overall, approximately one-third of liveborn children with prenatal ZIKV exposure presented with at least one abnormality compatible with congenital infection, while the risk to present with at least two abnormalities in combination was less than 1.0%.

Characteristics of children of the Microcephaly Epidemic Research Group Pediatric Cohort who developed postnatal microcephaly.

The number of studies published on postnatal microcephaly in children with Congenital Zika Syndrome is small, clinical presentations vary and aspects of the evolution of these children remain unclarified. The present case series examined clinical characteristics and assessed the growth velocity of the head circumference, weight and height Z-scores in 23 children who developed postnatal microcephaly during follow-up in the Microcephaly Epidemic Research Group Pediatric Cohort. To estimate the change in the head circumference, weight and height Z-scores over time and compare the mean difference between sexes, we used multilevel mixed-effects linear regressions with child-specific random effects. Among these children, 60.9% (n = 14/23) presented with craniofacial disproportion, 60.9% (n = 14/23) with strabismus, 47.8% (n = 11/23) with early onset seizures, 47.8% (n = 11/23) with dysphagia and 43.5% (n = 10/23) with arthrogryposis. Of the 82.7% (n = 19/23) children who underwent neuroimaging, 78.9% (n = 15/19) presented with alterations in the central nervous system. Monthly growth velocity, expressed in Z-scores, of the head circumference was - 0.098 (95% CI % - 0.117 to - 0.080), of weight was: - 0.010 (95%-CI - 0.033 to 0.014) and of height was: - 0.023 (95%-CI - 0.046 to 0.0001). Postnatal microcephaly occurred mainly in children who had already presented with signs of severe brain damage at birth; there was variability in weight and height development, with no set pattern.

Co-circulation of Chikungunya Virus during the 2015-2017 Zika Virus Outbreak in Pernambuco, Brazil: An Analysis of the Microcephaly Epidemic Research Group Pregnancy Cohort.

Co-circulation of arthropod-borne viruses, particularly those with shared mosquito vectors like Zika (ZIKV) and Chikungunya (CHIKV), is increasingly reported. An accurate differential diagnosis between ZIKV and CHIKV is of high clinical importance, especially in the context of pregnancy, but remains challenging due to limitations in the availability of specialized laboratory testing facilities. Using data collected from the prospective pregnancy cohort study of the Microcephaly Epidemic Research Group, which followed up pregnant persons with rash during the peak and decline of the 2015-2017 ZIKV epidemic in Recife, Pernambuco, Brazil, this study aims to describe the geographic and temporal distribution of ZIKV and CHIKV infections and to investigate the extent to which ZIKV and CHIKV infections may be clinically differentiable. Between December 2015 and June 2017, we observed evidence of co-circulation with laboratory confirmation of 213 ZIKV mono-infections, 55 CHIKV mono-infections, and 58 sequential ZIKV/CHIKV infections (i.e., cases with evidence of acute ZIKV infection with concomitant serological evidence of recent CHIKV infection). In logistic regressions with adjustment for maternal age, ZIKV mono-infected cases had lower odds than CHIKV mono-infected cases of presenting with arthralgia (aOR, 99% CI: 0.33, 0.15-0.74), arthritis (0.35, 0.14-0.85), fatigue (0.40, 0.17-0.96), and headache (0.44, 0.19-1.90). However, sequential ZIKV/CHIKV infections complicated discrimination, as they did not significantly differ in clinical presentation from CHIKV mono-infections. These findings suggest clinical symptoms alone may be insufficient for differentiating between ZIKV and CHIKV infections during pregnancy and therefore laboratory diagnostics continue to be a valuable tool for tailoring care in the event of arboviral co-circulation.

Neighbourhood-level income and Zika virus infection during pregnancy in Recife, Pernambuco, Brazil: an ecological perspective, 2015-2017.

Zika virus (ZIKV) infections during pregnancy can lead to adverse neurodevelopmental and clinical outcomes in congenitally infected offspring. As the city of Recife in Pernambuco State, Brazil-the epicentre of the Brazilian microcephaly epidemic-has considerable disparities in living conditions, this study used an ecological approach to investigate the association between income at the neighbourhood level and the risk of ZIKV infections in pregnant individuals between December 2015 and April 2017. The spatial distribution of pregnant individuals with ZIKV infection was plotted on a map of Recife stratified into four categories based on mean monthly income of household heads. Additionally, a Poisson regression model with robust variance was fitted to compare proportions of ZIKV infections among pregnant individuals in relation to the mean monthly income of household heads, based on the 2010 census data, across 94 neighbourhoods in Recife. The results provide evidence that the risk of ZIKV infection to pregnant individuals was higher among those residing in lower-income neighbourhoods: relative to neighbourhoods that had a mean monthly income of ≥5 times minimum wage, neighbourhoods with <1 and 1 to <2 times minimum wage had more than four times the risk (incidence rate ratio, 95% CI 4.08, 1.88 to 8.85 and 4.30, 2.00 to 9.20, respectively). This study provides evidence of a strong association between neighbourhood-level income and ZIKV infection risks in the pregnant population of Recife. In settings prone to arboviral outbreaks, locally targeted interventions to improve living conditions, sanitation, and mosquito control should be a key focus of governmental interventions to reduce risks associated with ZIKV infections during pregnancy.

Zika virus infection and microcephaly: spatial analysis and socio-environmental determinants in a region of high Aedes aegypti infestation in the Central-West Region of Brazil.

BACKGROUND: More than 5 years after the Zika virus (ZIKV) epidemic, Zika infection remains a major concern in regions with high Aedes infestation. The objectives of this study were (i) to identify clusters of ZIKV infection and microcephaly, and/or central nervous system (CNS) alterations associated with congenital infection during the epidemic peak in 2016 and subsequently, in 2017 and 2018; (ii) to measure the non-spatial correlation between ZIKV infection and microcephaly and/or CNS alterations associated with congenital infection; and (iii) to analyse the sociodemographic/economic, health, and environmental determinants associated with the incidence of ZIKV in a region of high infestation by Aedes aegypti in the Central-West Region of Brazil. METHODS: This ecological study analysed 246 municipalities in the state of Goiás (6.9 million inhabitants). The data were obtained from the Information System for Notifiable Diseases (ZIKV cases) and the Public Health Event Registry (microcephaly and/or CNS alterations associated with congenital infection). Incidence rates and prevalence of ZIKA infection were smoothed by an empirical Bayesian estimator (LEbayes), producing the local empirical Bayesian rate (LEBR). In the spatial analysis, ZIKV infection and microcephaly cases were georeferenced by the municipality of residence for 2016 and grouped for 2017 and 2018. Global Moran's I and the Hot Spot Analysis tool (Getis-Ord Gi* statistics) were used to analyse the spatial autocorrelation and clusters of ZIKV infection and microcephaly, respectively. A generalised linear model from the Poisson family was used to assess the association between ecological determinants and the smoothing incidence rate of ZIKV infection. RESULTS: A total of 9892 cases of acute ZIKV infection and 121 cases of microcephaly were confirmed. The mean LEBR of the ZIKV infection in the 246 municipalities was 22.3 cases/100,000 inhabitants in 2016, and 10.3 cases/100,000 inhabitants in 2017 and 2018. The LEBR of the prevalence rate of microcephaly and/or CNS alterations associated with congenital infection was 7 cases/10,000 live births in 2016 and 2 cases/10,000 live births during 2017-2018. Hotspots of ZIKV infection and microcephaly cases were identified in the capital and neighbouring municipalities in 2016, with new clusters in the following years. In a multiple regression Poisson analysis, ZIKV infection was associated with higher population density, the incidence of dengue, Aedes larvae infestation index, and average rainfall. The important determinant of ZIKV infection incidence reduction was the increase in households attended by endemic disease control agents. CONCLUSIONS: Our analyses were able to capture, in a more granular way, aspects that make it possible to inform public managers of the sentinel areas identified in the post-epidemic hotspots.

The Microcephaly Epidemic Research Group Paediatric Cohort (MERG-PC): A Cohort Profile.

This cohort profile aims to describe the ongoing follow-up of children in the Microcephaly Epidemic Research Group Paediatric Cohort (MERG-PC). The profile details the context and aims of the study, study population, methodology including assessments, and key results and publications to date. The children that make up MERG-PC were born in Recife or within 120 km of the city, in Pernambuco/Brazil, the epicentre of the microcephaly epidemic. MERG-PC includes children from four groups recruited at different stages of the ZIKV microcephaly epidemic in Pernambuco, i.e., the Outpatient Group (OG/n = 195), the Microcephaly Case-Control Study (MCCS/n = 80), the MERG Pregnant Women Cohort (MERG-PWC/n = 336), and the Control Group (CG/n = 100). We developed a comprehensive array of clinical, laboratory, and imaging assessments that were undertaken by a 'task force' of clinical specialists in a single day at 3, 6, 12, 18 months of age, and annually from 24 months. Children from MCCS and CG had their baseline assessment at birth and children from the other groups, at the first evaluation by the task force. The baseline cohort includes 711 children born between February 2015 and February 2019. Children's characteristics at baseline, excluding CG, were as follows: 32.6% (184/565) had microcephaly, 47% (263/559) had at least one physical abnormality, 29.5% (160/543) had at least one neurological abnormality, and 46.2% (257/556) had at least one ophthalmological abnormality. This ongoing cohort has contributed to the understanding of the congenital Zika syndrome (CZS) spectrum. The cohort has provided descriptions of paediatric neurodevelopment and early epilepsy, including EEG patterns and treatment response, and information on the frequency and characteristics of oropharyngeal dysphagia; cryptorchidism and its surgical findings; endocrine dysfunction; and adenoid hypertrophy in children with Zika-related microcephaly. The study protocols and questionnaires were shared across Brazilian states to enable harmonization across the different studies investigating microcephaly and CZS, providing the opportunity for the Zika Brazilian Cohorts Consortium to be formed, uniting all the ZIKV clinical cohorts in Brazil.

Zika virus infection in pregnancy: a protocol for the joint analysis of the prospective cohort studies of the ZIKAlliance, ZikaPLAN and ZIKAction consortia.

INTRODUCTION: Zika virus (ZIKV) infection in pregnancy has been associated with microcephaly and severe neurological damage to the fetus. Our aim is to document the risks of adverse pregnancy and birth outcomes and the prevalence of laboratory markers of congenital infection in deliveries to women experiencing ZIKV infection during pregnancy, using data from European Commission-funded prospective cohort studies in 20 centres in 11 countries across Latin America and the Caribbean. METHODS AND ANALYSIS: We will carry out a centre-by-centre analysis of the risks of adverse pregnancy and birth outcomes, comparing women with confirmed and suspected ZIKV infection in pregnancy to those with no evidence of infection in pregnancy. We will document the proportion of deliveries in which laboratory markers of congenital infection were present. Finally, we will investigate the associations of trimester of maternal infection in pregnancy, presence or absence of maternal symptoms of acute ZIKV infection and previous flavivirus infections with adverse outcomes and with markers of congenital infection. Centre-specific estimates will be pooled using a two-stage approach. ETHICS AND DISSEMINATION: Ethical approval was obtained at each centre. Findings will be presented at international conferences and published in peer-reviewed open access journals and discussed with local public health officials and representatives of the national Ministries of Health, Pan American Health Organization and WHO involved with ZIKV prevention and control activities.

The influence of meteorological variables on the oviposition dynamics of Aedes aegypti (Diptera: Culicidae) in four environmentally distinct areas in northeast Brazil.

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 (ß = 45.7; 95% CI: 26.3 - 65.0) and lower wind speed (ß = -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.

Zika virus infection in pregnancy: Establishing a case definition for clinical research on pregnant women with rash in an active transmission setting.

Defining cases of Zika virus (ZIKV) infection is a critical challenge for epidemiological research. Due to ZIKV's overlapping clinical features and potential immunologic cross-reactivity with other flaviviruses and the current lack of an optimal ZIKV-specific diagnostic assay, varying approaches for identifying ZIKV infections have been employed to date. This paper presents the laboratory results and diagnostic criteria developed by the Microcephaly Epidemic Research Group for defining cases of maternal ZIKV infection in a cohort of pregnant women with rash (N = 694) recruited during the declining 2015-2017 epidemic in northeast Brazil. For this investigation, we tested maternal sera for ZIKV by quantitative reverse transcription polymerase chain reaction (qRT-PCR), Immunoglobulin (Ig) M and IgG3 enzyme-linked immunosorbent assays (ELISAs), and Plaque Reduction Neutralization Test (PRNT50). Overall, 23.8% of participants tested positive by qRT-PCR during pregnancy (range of detection: 0-72 days after rash onset). However, the inter-assay concordance was lower than expected. Among women with qRT-PCR-confirmed ZIKV and further testing, only 10.1% had positive IgM tests within 90 days of rash, and only 48.5% had ZIKV-specific PRNT50 titers ≥20 within 1 year of rash. Given the complexity of these data, we convened a panel of experts to propose an algorithm for identifying ZIKV infections in pregnancy based on all available lines of evidence. When the diagnostic algorithm was applied to the cohort, 26.9% of participants were classified as having robust evidence of a ZIKV infection during pregnancy, 4.0% as having moderate evidence, 13.3% as having limited evidence of a ZIKV infection but with uncertain timing, and 19.5% as having evidence of an unspecified flavivirus infection before or during pregnancy. Our findings suggest that integrating longitudinal data from nucleic acid and serologic testing may enhance diagnostic sensitivity and underscore the need for an on-going dialogue regarding the optimization of strategies for defining cases of ZIKV in research.

Increase in dental caries and change in the socioeconomic profile of families in a child cohort of the primary health care in Northeast Brazil.

BACKGROUND: Factors associated with increases in dental caries and changes in the family socioeconomic profile were investigated in a paediatric primary health care (PHC) cohort in Northeast Brazil during the implementation of social and income transfer programmes. METHOD: A prospective analytical study compared data from two surveys on caries in primary dentition conducted in 2006 (age: 18-36 months, n = 1045) and 2010 (age: 5-7 years). Data from the sample recruited and re-examined in 2010 (n = 469) were analysed. Prevalences (P) and the mean primary decayed, missing and filled teeth (dmft) index, cumulative incidence and mean increase were calculated. Differences (p ≤ 0.05 and 95% CI) in dmft ≥1 were identified via McNemar's test. Differences in the mean dmft were evaluated according to socioeconomic variables (Kruskal-Wallis test and p ≤ 0.05). Multivariate analysis with a negative binomial model was used for the risk factors associated with increasing dmft. In the univariate analyses, nonparametric methods (Kruskal-Wallis test) were used to compare subsamples. Variables with p ≤ 0.20 were included in the multivariate model and retained when p ≤ 0.05. RESULTS: The prevalence and mean dmft (18-36 months and 5-7 years: p = 28.6 and 68.9%, mean = 1.01 and 3.46, respectively) and variation in mean dmft changed significantly (p < 0.005) with the education level and occupation of the mother; the prevalence and mean dmft were lower for higher maternal education level and maternal participation in the labour market. The cumulative incidence and mean increase in dmft were 8.71% and 2.45, respectively. Common risk predictors for increases in caries were consumption of sweets (RR = 1.53, 95% CI 1.09-2.14) and attendance at public schools (RR = 1.49, 95% CI: 1.81-1.89). Use of private clinical services was a protective factor (RR = 0.68, 95% CI 0.54-0.87). CONCLUSION: Increases in caries were observed despite positive changes in the distribution of socioeconomic indicators for the analysed children's families. The risk factors identified for the increase in caries suggest ongoing problems regarding the effectiveness of intersectoral and health measures for controlling caries in populations exposed to PHC programmes.

Performance Assessment of a Trypanosoma cruzi Chimeric Antigen in Multiplex Liquid Microarray Assays.

Diagnosing chronic Chagas disease (CD) requires antibody-antigen detection methods, which are traditionally based on enzymatic assay techniques whose performance depend on the type and quality of antigen used. Previously, 4 recombinant chimeric proteins from the Instituto de Biologia Molecular do Paraná (IBMP-8.1 to 8.4) comprising immuno-dominant regions of diverse Trypanosoma cruzi antigens showed excellent diagnostic performance in enzyme-linked immunosorbent assays. Considering that next-generation platforms offer improved CD diagnostic accuracy with different T. cruzi-specific recombinant antigens, we assessed the performance of these chimeras in liquid microarrays (LMAs). The chimeric proteins were expressed in Escherichia coli and purified by chromatography. Sera from 653 chagasic and 680 healthy individuals were used to assess the performance of these chimeras in detecting specific anti-T. cruzi antibodies. Accuracies ranged from 98.1 to 99.3%, and diagnostic odds ratio values were 3,548 for IBMP-8.3, 4,826 for IBMP-8.1, 7,882 for IBMP-8.2, and 25,000 for IBMP-8.4. A separate sera bank (851 samples) was employed to assess cross-reactivity with other tropical diseases. Leishmania, a pathogen with high similarity to T. cruzi, showed cross-reactivity rates ranging from 0 to 2.17%. Inconclusive results were negligible (0 to 0.71%). Bland-Altman and Deming regression analysis based on 200 randomly selected CD-positive and negative samples demonstrated interchangeability with respect to CD diagnostic performance in both singleplex and multiplex assays. Our results suggested that these chimeras can potentially replace antigens currently used in commercially available assay kits. Moreover, the use of multiplex platforms, such as LMA assays employing 2 or more IBMP antigens, would abrogate the need for 2 different testing techniques when diagnosing CD.

Saúde na Copa: The World's First Application of Participatory Surveillance for a Mass Gathering at FIFA World Cup 2014, Brazil.

BACKGROUND: The 2005 International Health Regulations (IHRs) established parameters for event assessments and notifications that may constitute public health emergencies of international concern. These requirements and parameters opened up space for the use of nonofficial mechanisms (such as websites, blogs, and social networks) and technological improvements of communication that can streamline the detection, monitoring, and response to health problems, and thus reduce damage caused by these problems. Specifically, the revised IHR created space for participatory surveillance to function, in addition to the traditional surveillance mechanisms of detection, monitoring, and response. Participatory surveillance is based on crowdsourcing methods that collect information from society and then return the collective knowledge gained from that information back to society. The spread of digital social networks and wiki-style knowledge platforms has created a very favorable environment for this model of production and social control of information. OBJECTIVE: The aim of this study was to describe the use of a participatory surveillance app, Healthy Cup, for the early detection of acute disease outbreaks during the Fédération Internationale de Football Association (FIFA) World Cup 2014. Our focus was on three specific syndromes (respiratory, diarrheal, and rash) related to six diseases that were considered important in a mass gathering context (influenza, measles, rubella, cholera, acute diarrhea, and dengue fever). METHODS: From May 12 to July 13, 2014, users from anywhere in the world were able to download the Healthy Cup app and record their health condition, reporting whether they were good, very good, ill, or very ill. For users that reported being ill or very ill, a screen with a list of 10 symptoms was displayed. Participatory surveillance allows for the real-time identification of aggregates of symptoms that indicate possible cases of infectious diseases. RESULTS: From May 12 through July 13, 2014, there were 9434 downloads of the Healthy Cup app and 7155 (75.84%) registered users. Among the registered users, 4706 (4706/7155, 65.77%) were active users who posted a total of 47,879 times during the study period. The maximum number of users that signed up in one day occurred on May 30, 2014, the day that the app was officially launched by the Minister of Health during a press conference. During this event, the Minister of Health announced the special government program Health in the World Cup on national television media. On that date, 3633 logins were recorded, which accounted for more than half of all sign-ups across the entire duration of the study (50.78%, 3633/7155). CONCLUSIONS: Participatory surveillance through community engagement is an innovative way to conduct epidemiological surveillance. Compared to traditional epidemiological surveillance, advantages include lower costs of data acquisition, timeliness of information collected and shared, platform scalability, and capacity for integration between the population being served and public health services.

Accuracy of chimeric proteins in the serological diagnosis of chronic chagas disease - a Phase II study.

BACKGROUND: The performance of current serologic tests for diagnosing chronic Chagas disease (CD) is highly variable. The search for new diagnostic markers has been a constant challenge for improving accuracy and reducing the number of inconclusive results. METHODOLOGY/PRINCIPAL FINDINGS: Here, four chimeric proteins (IBMP-8.1 to -8.4) comprising immunodominant regions of different Trypanosoma cruzi antigens were tested by enzyme-linked immunosorbent assay. The proteins were used to detect specific anti-T. cruzi antibodies in the sera of 857 chagasic and 689 non-chagasic individuals to evaluate their accuracy for chronic CD diagnosis. The antigens were recombinantly expressed in Escherichia coli and purified by chromatographic methods. The sensitivity and specificity values ranged from 94.3% to 99.3% and 99.4% to 100%, respectively. The diagnostic odds ratio (DOR) values were 6,462 for IBMP-8.1, 3,807 for IBMP-8.2, 32,095 for IBMP-8.3, and 283,714 for IBMP-8.4. These chimeric antigens presented DORs that were higher than the commercial test Pathozyme Chagas. The antigens IBMP-8.3 and -8.4 also showed DORs higher than the Gold ELISA Chagas test. Mixtures with equimolar concentrations were tested in order to improve the diagnosis accuracy of negative samples with high signal and positive samples with low signal. However, no gain in accuracy was observed relative to the individual antigens. A total of 1,079 additional sera were used to test cross-reactivity to unrelated diseases. The cross-reactivity rates ranged from 0.37% to 0.74% even for Leishmania spp., a pathogen showing relatively high genome sequence identity to T. cruzi. Imprecision analyses showed that IBMP chimeras are very stable and the results are highly reproducible. CONCLUSIONS/SIGNIFICANCE: Our findings indicate that the IBMP-8.4 antigen can be safely used in serological tests for T. cruzi screening in blood banks and for chronic CD laboratory diagnosis.

High frequency of pre-existing neutralizing antibody responses in patients with dengue during an outbreak in Central Brazil.

BACKGROUND: This study aims to identify dengue neutralizing antibody response in patients with dengue from a well-characterized cohort during an outbreak in central Brazil, 2012-2013. METHODS: We analyzed paired samples from 40 patients with severe dengue and 20 patients with dengue. Eligibility criteria were: IgM, NS1Ag and/or RT-PCR positivity and positive IgG result. Plaque reduction neutralization test (PRNT50) from DENV-1 to DENV-4 was performed to identify serotype-specific NAbs response. An infecting serotype was defined as ≥4-fold increase in DENV NAbs in paired samples. Monotypic response was classified as PRNT50 ≥ 1/20 to only one DENV serotype, and multitypic response was considered to be PRNT50 ≥ 1/20 to two or more serotypes simultaneously. RESULTS: Patients were mainly adults. Virological dengue infection was confirmed by RT-PCR: DENV-4(n = 14) and DENV-1(n = 10). Forty-four out of 60(73.3 %) patients had NAbs to DENV-4, DENV-1(68.3 %), DENV-2(68.3 %) and DENV-3(61.6 %) respectively. Fifteen percent of the cases presented monotypic response, whereas 85 % had multitypic response. DENV-4 infected-patients presented the greatest difference in PRNT50 titers compared with other serotypes. Pre-existing DENV NAbs was not correlated with disease severity. This was the first time that DENV-4 was implicated in an epidemic in the region. CONCLUSION: Our data indicates high exposure of multiple DENV serotypes in all age groups in the pre-dengue vaccine era and also previous to Zika virus introduction in Brazil.

Chronic Chagas Disease Diagnosis: A Comparative Performance of Commercial Enzyme Immunoassay Tests.

There is a significant heterogeneity in reported performance of serological assays for Chagas disease diagnosis. The conventional serology testing in laboratory diagnosis and in blood banks is unsatisfactory because of a high number of inconclusive and misclassified results. We aimed to assess the quality of four commercially available enzyme-linked immunosorbent assay tests for their ability to detect Trypanosoma cruzi antibodies in 685 sera samples. Cross-reactivity was assessed by using 748 sera from patients with unrelated diseases. Initially, we found that the reactivity index against T. cruzi antigen was statistically higher in sera from Chagas disease patients compared with those from non-chagasic patients, supporting the notion that all evaluated tests have a good discriminatory ability toward the diagnosis of T. cruzi infection in patients in the chronic phase of the disease. Although all tests were similarly sensitive for diagnosing T. cruzi infection, there were significant variations in terms of specificity and cross-reactivity among them. Indeed, we obtained divergent results when testing sera from patient with unrelated diseases, particularly leishmaniasis, with the levels of cross-reactivity being higher in tests using whole T. cruzi extracts compared with those using recombinant proteins. Our data suggest that all four tests may be used for the laboratory diagnosis and routine blood screening diagnose for Chagas disease. We also emphasize that, despite their general good performance, caution is needed when analyzing the results when these tests are performed in areas where other diseases, particularly leishmaniasis, are endemic.

Economic Impact of Dengue: Multicenter Study across Four Brazilian Regions.

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.

Social Conditions and High Levels of Dental Caries in Five-year-old Children in Brazil.

PURPOSE: To identify factors associated with dental caries experience in at least four primary teeth in five-year-old Brazilian children. METHODS: This was a case-control study, part of a prior investigation of the prevalence of dental caries in the primary dentition of five-year-old children conducted in 2006 in public health services in Recife, Brazil. Study patients had a decayed, missing, and filled teeth [dmft] score ≥ 4 and controls had a dmft score ≤ 3. The cutoff point was based on the dmft scores mean value of the study population. Categories of independent variables were sociodemographic, family structure, oral health behavior, and use of oral health services. Crude odds ratios and 95% CI were calculated. Variables associated with dmft greater than or equal to four at a significance level of P≤.20 in univariate analyses were included in multivariate logistic regression models using a backward stepwise variable selection method and permanence criterion in the final model of P≤.10. RESULTS: The study included 479 children (171 study patients and 308 controls). After controlling for confounding variables, factors associated with a dmft score ≥ 4 were children living in households with at least six people, residence in a poor area, caregiver's low educational level, consumption of sweets between meals, and the reason for and location of oral health care seeking. CONCLUSION: Most factors associated with high levels of dental caries in five-year-old children were related to the social conditions in which they lived.