Prevalence of multidrug-resistant tuberculosis in Latin America and the Caribbean: a systematic review and meta-analysis.

OBJECTIVES: To evaluate the prevalence of multidrug-resistant tuberculosis (MDR-TB) in individuals living in Latin America and the Caribbean (LAC). METHODS: We searched the MEDLINE, Embase and Literatura Latino Americana e do Caribe em Ciências da Saúde (Lilacs) databases until 08 August 2019 for all studies on the subject, without time or language restrictions. Original studies reporting the prevalence of infection with Mycobacterium tuberculosis resistant to isoniazid and rifampicin simultaneously (MDR) in LAC, the prevalence of resistance in cases with no previous treatment (new cases) and the prevalence of resistance in previously treated cases were selected. Considering the expected heterogeneity between studies, all analyses were performed using the random effects model, and heterogeneity was assessed using the I2 statistic. RESULTS: We included 91 studies from 16 countries. The estimated overall prevalence was 13.0% (95% CI 12.0-14.0%), and the heterogeneity between studies was substantial (I2  = 96.1%). In the subgroup analyses, it was observed that the prevalence of MDR-TB among new cases was 7.0% (95% CI 6.0-7.0%) and in previously treated cases was 26.0% (95% CI 24.0-28.0%). CONCLUSIONS: This review highlights multidrug resistance to antituberculosis drugs in LAC, indicating that prevention strategies have not been effective. Government institutions should invest heavily in strategies for early diagnosis and the rapid availability of effective treatments and prioritise adequate protection for health professionals. In addition, screening programmes should be adopted to prevent secondary cases.

OBJECTIFS: Evaluer la prévalence de la tuberculose multirésistante (TB-MDR) chez les personnes vivant en Amérique latine et dans les Caraïbes (ALC). MÉTHODES: Nous avons effectué des recherches dans les bases de données Medline, EMBASE et Literatura Latino Americana e do Caribe em Ciências da Saúde (Lilas) jusqu'au 08 août 2019 pour toutes les études sur le sujet, sans restriction de temps ou de langue. Des études originales faisant état de la prévalence de l'infection à Mycobacterium tuberculosis résistante à l'isoniazide et à la rifampicine simultanément (MDR) dans la région ALC, de la prévalence de la résistance dans les cas sans traitement antérieur (nouveaux cas) et de la prévalence de la résistance dans les cas précédemment traités ont été sélectionnées. Compte tenu de l'hétérogénéité attendue entre les études, toutes les analyses ont été effectuées à l' aide du modèle à effets aléatoires et l'hétérogénéité a été évaluée à l' aide de la statistique I2 . RÉSULTATS: Nous avons inclus 91 études de 16 pays. La prévalence globale était estimée à 13,0% (IC95%: 12,0%-14,0%) et l'hétérogénéité entre les études était importante (I2 = 96,1%). Dans les analyses des sous-groupes, il a été observé que la prévalence de la TB-MDR parmi les nouveaux cas était de 7,0% (IC95%: 6,0%-7,0%) et dans les cas précédemment traités de 26,0% (IC95%: 24,0%-28,0%). CONCLUSIONS: Cette revue met en évidence la multirésistance aux médicaments antituberculeux dans la région ALC, indiquant que les stratégies de prévention n'ont pas été efficaces. Les institutions gouvernementales devraient investir massivement dans les stratégies de diagnostic précoce et la disponibilité rapide de traitements efficaces et accorder la priorité à une protection adéquate pour les professionnels de la santé. De plus, des programmes de dépistage devraient être adoptés pour prévenir les cas secondaires.

MTTP polymorphisms and hepatic steatosis in individuals chronically infected with hepatitis C virus.

Polymorphisms in the microsomal triglyceride transfer protein (MTTP) gene were genotyped in individuals who were chronically infected with hepatitis C virus (HCV). In the 236 patients, the frequencies of risk alleles of the -164T/C (rs1800804), -400A/T (rs1800803) and H297Q (rs2306985) polymorphisms were 0.30, 0.41 and 0.50, respectively. A significant association between the risk alleles of the -164T/C and -400A/T polymorphisms combined with HCV genotype 3 infection and the occurrence of steatosis was detected (p = 0.004 and p = 0.032), suggesting that a combination of host and viral factors can potentially be used to predict hepatic steatosis.

A spatial case-control study on symptomatic and inapparent primary dengue infections in an endemic city in Brazil.

We conducted a spatial case-control study nested in a dengue incidence cohort to explore the role of the spatial and socioeconomic factors in the proportion of symptomatic (cases) and inapparent primary dengue virus infections (controls). Cohort participants were children and adolescents (2 to 16 years of age) at the beginning of the follow-up. Case definitions were, for symptomatic cases, fever plus a positive lab result for acute dengue (NS1, RT-PCR, ELISA IgM/IgG), and for inapparent infection a positive result for dengue IgG (ELISA) in subjects without symptoms and with a previously negative result at baseline. The covariates included sociodemographic factors, residential location, and socioeconomic context variables of the census tracts of residence of cases and controls. We used principal component analysis to reduce the contextual covariates, with the component values assigned to each one based on their residences. The data were modeled in a Bayesian context, considering the spatial dependence. The final sample consisted of 692 children, 274 cases and 418 controls, from the first year of follow-up (2014-2015). Being male, older age, higher educational level of the head of the family and having a larger number of rooms in the household were associated with a greater chance of presenting dengue symptomatic infection at the individual level. The contextual covariates were not associated with the outcome. Inapparent dengue infection has extensive epidemiological consequences. Relying solely on notifications of symptomatic dengue infections underestimates the number of cases, preserves a silent source of the disease, potentially spreading the virus to unaffected areas.

Assessing the risks for stillbirth in São Paulo, Brazil: protocol for a multidisciplinary case-control study - FetRisks.

Stillbirth is a fundamental component of childhood mortality, but its causes are still insufficiently understood. This study aims to explore stillbirth risk factors by using a multidisciplinary approach to stimulate public policies and protocols to prevent stillbirth, improve maternal care and support bereaved families. METHODS AND ANALYSIS: In this case-control study with stillbirths and live births in 14 public hospitals in São Paulo, mothers are interviewed at hospitals after delivery, and hospital records and prenatal care registries are reviewed. Maternal and umbilical cord blood samples and placentas are collected to analyse angiogenesis and infection biomarkers, and the placenta's anatomopathological exam. Air pollutant exposure is estimated through the participant's residence and work addresses. Traditional and non-invasive autopsies by image-guided histopathology are conducted in a subset of stillbirths. Subsample mothers of cases are interviewed at home 2 months after delivery on how they were dealing with grief. Information contained in the official prenatal care registries of cases and controls is being compiled. Hospital managers are interviewed about the care offered to stillbirth mothers. Data analysis will identify the main risk factors for stillbirth, investigate their interrelations, and evaluate health services care and support for bereaved families. We hope this project will contribute to the understanding of stillbirth's risk factors and related health services in Brazil, providing new knowledge about this central public health problem, contributing to the improvement of public policies and prenatal and puerperal care, helping to prevent stillbirths and improve the healthcare and support for bereaved families. ETHICS AND DISSEMINATION: This study protocol was approved by the Ethics Committee of the Municipal Health Secretary (process no 16509319.0.3012.5551) and of the Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (process no 16509319.0.0000.0068). Results will be communicated to the study participants, policy-makers and the scientific community.

Prevalence and risk factors of Hepatitis C virus infection in Brazil, 2005 through 2009: a cross-sectional study.

BACKGROUND: Hepatitis C chronic liver disease is a major cause of liver transplant in developed countries. This article reports the first nationwide population-based survey conducted to estimate the seroprevalence of HCV antibodies and associated risk factors in the urban population of Brazil. METHODS: The cross sectional study was conducted in all Brazilian macro-regions from 2005 to 2009, as a stratified multistage cluster sample of 19,503 inhabitants aged between 10 and 69 years, representing individuals living in all 26 State capitals and the Federal District. Hepatitis C antibodies were detected by a third-generation enzyme immunoassay. Seropositive individuals were retested by Polymerase Chain Reaction and genotyped. Adjusted prevalence was estimated by macro-regions. Potential risk factors associated with HCV infection were assessed by calculating the crude and adjusted odds ratios, 95% confidence intervals (95% CI) and p values. Population attributable risk was estimated for multiple factors using a case-control approach. RESULTS: The overall weighted prevalence of hepatitis C antibodies was 1.38% (95% CI: 1.12%-1.64%). Prevalence of infection increased in older groups but was similar for both sexes. The multivariate model showed the following to be predictors of HCV infection: age, injected drug use (OR = 6.65), sniffed drug use (OR = 2.59), hospitalization (OR = 1.90), groups socially deprived by the lack of sewage disposal (OR = 2.53), and injection with glass syringe (OR = 1.52, with a borderline p value). The genotypes 1 (subtypes 1a, 1b), 2b and 3a were identified. The estimated population attributable risk for the ensemble of risk factors was 40%. Approximately 1.3 million individuals would be expected to be anti-HCV-positive in the country. CONCLUSIONS: The large estimated absolute numbers of infected individuals reveals the burden of the disease in the near future, giving rise to costs for the health care system and society at large. The known risk factors explain less than 50% of the infected cases, limiting the prevention strategies. Our findings regarding risk behaviors associated with HCV infection showed that there is still room for improving strategies for reducing transmission among drug users and nosocomial infection, as well as a need for specific prevention and control strategies targeting individuals living in poverty.

Seroprevalence of SARS-CoV-2 in Brazil: A systematic review and meta-analysis.

OBJECTIVES: To summarize the data on SARS-CoV-2 seroprevalence surveys conducted in Brazil before the introduction of vaccines METHODS: The authors conducted a systematic review and meta-analysis on the seroprevalence of SARS-CoV-2 infection in Brazil. The present review followed the PRISMA guidelines. The authors searched Medline, Embase, and LILACS databases for serologic surveys conducted in the Brazilian population, in the period from 01/10/2019 to 07/11/2021, without language restrictions. The authors included studies that presented data concerning SARS-CoV-2 antibodies seroprevalence in Brazil and had a sample size ≥50 individuals. Considering the expected heterogeneity between studies, all analyses were performed using the random effects model, and heterogeneity was assessed using the I2 statistic RESULTS: Of 586 publications identified in the initial searches, 54 were included in the review and meta-analysis, which contained the results of 135 surveys, with 336,620 participants. The estimated seroprevalence was 11.0%, ranging from 1.0% to 83.0%, with a substantial heterogeneity (I2 = 99.55%). In subgroup analyses, the authors observed that the prevalence of SARS-CoV-2 antibodies was 13.0% in blood donors, 9.0% in the population-based surveys, 13% in schoolchildren, and 11.0% in healthcare workers. CONCLUSIONS: Seroprevalence increases over time. Large differences were observed among the regions of the country. It was higher in the Northern region, decreasing towards the South. The present results may contribute to the analysis of the spread of SARS-CoV-2 infection in the Brazilian population before vaccination, one of the factors that may be influencing the clinical presentation of COVID-19 cases related to the new variants, as well as the effectiveness of the vaccination program.

Local protection bubbles: an interpretation of the slowdown in the spread of coronavirus in the city of São Paulo, Brazil, in July 2020.

After four months of fighting the pandemic, the city of São Paulo, Brazil, entered a phase of relaxed social distancing measures in July 2020. Simultaneously, there was a decline in the social distancing rate and a reduction in the number of cases, fatalities, and hospital bed occupancy. To understand the pandemic dynamics in the city of São Paulo, we developed a multi-agent simulation model. Surprisingly, the counter-intuitive results of the model followed the city's reality. We argue that this phenomenon could be attributed to local bubbles of protection that emerged in the absence of contagion networks. These bubbles reduced the transmission rate of the virus, causing short and temporary reductions in the epidemic curve - but manifested as an unstable equilibrium. Our hypothesis aligns with the virus spread dynamics observed thus far, without the need for ad hoc assumptions regarding the natural thresholds of collective immunity or the heterogeneity of the population's transmission rate, which may lead to erroneous predictions. Our model was designed to be user-friendly and does not require any scientific or programming expertise to generate outcomes on virus transmission in a given location. Furthermore, as an input to start our simulation model, we developed the COVID-19 Protection Index as an alternative to the Human Development Index, which measures a given territory vulnerability to the coronavirus and includes characteristics of the health system and socioeconomic development, as well as the infrastructure of the city of São Paulo.

Factors Associated with Spontaneous Clearance of Recently Acquired Hepatitis C Virus among HIV-Positive Men in Brazil.

INTRODUCTION: The objective of the present study was to describe the clinical and epidemiological aspects of recently acquired hepatitis C virus (HCV) infection and the frequency of its spontaneous clearance in a people living with the human immunodeficiency virus (PLWH) cohort. METHODS: We reviewed the medical records from all PLWH at the human immunodeficiency virus (HIV) outpatient reference clinic affiliated with the University of São Paulo, Brazil, and identified, by immunoassays and RNA-PCR individuals who acquired HCV infection between January 2015 and December 2017. The factors associated with subsequent spontaneous clearance of the infection in this group were identified and analyzed. RESULTS: Among 3143 PLWH individuals, 362 (11.5%) were coinfected with HCV. Forty-eight (13.2%) of these subjects first became HCV-positive between January 2015 and December 2017. Spontaneous HCV clearance was documented in 23 individuals (47.9%). The majority of this latter group were male (83.3%), and the median age was 31 years (23-39). The main risk group for HCV acquisition was men who had sex with men (MSM) (89.5%). In a multivariate analysis, only an elevated CD4+ T lymphocyte count at the time of seroconversion was found to be associated with subsequent HCV clearance (p = 0.025). CONCLUSIONS: In HIV-infected individuals in Sao Paulo, Brazil, most cases of recent HCV transmission were by sexual exposure. In PLWH, particularly in MSM, the individual's CD4+ T lymphocyte count is a determinant of whether an acquired HCV infection will be prolonged or will spontaneously clear.

The Changing Epidemiology of Hepatitis C Virus Acquisition Among HIV-Infected Individuals in Brazil.

Identification of mechanisms of hepatitis C virus (HCV) acquisition among HIV-infected people is critical for prevention guidance. The aim of this study was to investigate risk factors for HCV infection and variations in HCV genotype distribution in a cohort of HIV-HCV coinfected patients in Brazil. This was a cross-sectional observational epidemiological study of a cohort of HIV-HCV coinfected individuals seen at a referral center for HIV-infected patients in the city of São Paulo between January and December 2017. The time of HCV acquisition, as determined by chart review, was categorized as before 2000, between 2000 and 2009, and from 2010 onward. HCV genotypes were determined by gene amplification and analysis. Among 3,143 HIV-infected individuals analyzed, 362 (11.5%) were HCV-HIV coinfected. Overall, the reported modes of HCV acquisition were sexual exposure in 172 (47.5%), injection drug use (IDU) in 86 (23.8%), use of inhaled drugs in 67 (18.5%) and blood transfusion in 10 (2.8%) individuals. All individuals who acquired HCV after IDU became infected before 2010. HCV acquisition by sexual contact was reported by 26.4%, 65.9%, and 63.8% of patients before 2000, between 2000 and 2009, and from 2010, respectively. There was an increase (p < .001) in the proportion of cases due to sexual transmission from the period before 2000 (26.4%) to between 2000 and 2009 (65.9%). There was no corresponding increase from 2000 and 2009 to after 2010 (p = .751). HCV genotype 1 was most prevalent at all time periods. The genotype 3 frequency decreased over time (test for trend p < .001), whereas genotype 4, extremely uncommon before 2010, became the second most prevalent genotype from 2010 onward. In HIV-infected individuals in Sao Paulo, Brazil, sexual transmission has replaced IDU as the most frequent mode of HCV acquisition.

Mortality due to hepatocellular carcinoma associated with hepatitis B and C viruses in the state of São Paulo, Brazil.

OBJECTIVE: This study aimed to describe and analyze the temporal and spatial distribution of deaths due to hepatocellular carcinoma (HCC) associated with hepatitis B (HBV) and C viruses (HCV) in the state of São Paulo. METHODS: This is an ecological study of HCC deaths associated with HBV and HCV in the state of São Paulo, from 2009 to 2017, with data from the Mortality Information System (SIM). The temporal trend was analyzed by linear regression with Prais-Winsten estimation. Deaths were described according to sociodemographic characteristics by means of absolute and relative frequencies and were spatially distributed according to the regional health department. RESULTS: It is found that 26.3% of deaths due to HCC were associated with HBV or HCV. A higher proportion of deaths due to HCC associated with HCV was observed (22.2%) when compared to HBV (3.9%). The mortality rate due to HCC associated with HBV showed a downward trend, and the mortality rate due to HCC associated with HCV showed a steady trend. Deaths of males, white individuals, those who aged from 50 to 59 years, and those who had 8-11 years of schooling predominated. Spatial analysis revealed a heterogeneous distribution of deaths in the state of São Paulo. CONCLUSIONS: The downward trend in mortality rates due to HCC associated with HBV shows an important advance in the disease control. However, the mortality rate due to HCC associated with HCV has remained stable throughout the study period. The spatial distribution of deaths may contribute to raise hypotheses for deeper knowledge of these diseases in the regions.

Brazilians' level of knowledge, attitudes and practices towards COVID-19: a cross-sectional study.

BACKGROUND: Brazil is facing increasing cycles of numbers of infected people and deaths resulting from coronavirus disease 2019 (COVID-19). This situation involves a series of factors, including the behavior of the population, that can be decisive for controlling the disease. OBJECTIVE: To determine the knowledge, attitudes and practices of the Brazilian population regarding COVID-19. DESIGN AND SETTING: Cross-sectional survey-type study, conducted using a population sample from different Brazilian states. METHODS: A quantitative, descriptive and analytical approach was used. Sampling was done according to convenience and via snowballing. The data collection instrument was a knowledge, attitudes and practices system. RESULTS: 1,655 people from all over Brazil participated in the survey; 80% were living in the southern region and 70.15% were female. More than 90% had knowledge and good attitudes relating to the means of transmission, preventive care and symptoms associated with COVID-19, although their knowledge and attitudes were not fully reflected in daily practices, for which there was lower adherence (80%). Greater knowledge was correlated with older participants, larger number of children, female sex and marital status; better attitude, with female sex and complete higher education; and better practices, with greater age, larger number of children and female sex. CONCLUSION: A large part of the population has general knowledge about COVID-19, but not all knowledge was applied in practice. Older people, females and university graduates stood out as the best informed and most committed to controlling the disease.

Prevalence of hepatitis A in the capitals of the States of North, Southeast and South regions of Brazil: decrease in prevalence and some consequences.

Hepatitis A virus (HAV) infection has been considered one of the leading causes of acute hepatitis. The aim of the present study was to estimate the prevalence of HAV among children and adolescents in a population-based study in the capitals of the States of the North, Southeast and South of Brazil and identify predictive factors for the infection. A multi-stage sampling was used to select subjects aged between 5-9 and 10-19 years. Individual and household levels aside from the level of variables in the areas were collected. The outcome was the total IgG antibodies to HAV levels detected using a commercial Enzyme Immuno Assay (EIA). The associations between HAV and the independent variables were assessed using the odds ratio. A multilevel analysis was performed by GLLAMM using the Stata software. The prevalence of HAV infection in the 5-9 and 10-19 age groups was 28.7% and 67.5%, respectively for the North, 20.6% and 37.7%, for the Southeast and 18.9% and 34.5% for the South Region. The prevalence of HAV increased according to age in all sites. Variables related to education at the individual level (North and South), family and area level (South and Southeast) and family income level (Southeast and South) were independently associated with HAV infection. This emphasizes the need for individualized strategies to prevent the infection.

Data on dengue incidence in South-eastern Brazil, 2014-2018.

Data from the routine surveillance systems have been extensively used to estimate the incidence of dengue. However, routine surveillance data frequently underestimate the diseases' incidence. Underreporting of dengue cases is related to the varying spectrum of its clinical presentation, with a large proportion of mild and asymptomatic infections, to its unspecific signs and symptoms, to the limitations of access to health care, and to the performance of the surveillance system itself [1-3]. In order to obtain accurate figures on dengue incidence, a cohort of children and adolescents was set up and followed during four years. The incidence of reported cases was used as a reference for the sample size calculation, which was stratified by age groups. A two-stage procedure was used to select the participants: census tracts were randomly selected, and within each one, a pre-determined number of children of each age group was randomly selected. The parents or legal guardians of the participating children and adolescents provided a written informed consent. In the first home visit, they responded to a questionnaire containing data on socio-demographic characteristics, housing, access to water, sewage, and garbage collection. Also, during the first visit a blood sample of the participating child/adolescent was collected for dengue baseline serology. Beginning in the week after the enrolment, the parent or legal guardian that was designated in the first visit received weekly phone calls for fever surveillance. If the child/adolescent had fever during the week, a nurse was dispatched to the family's home to collect more detailed data on the fever episode and collect a blood sample for dengue diagnosis (IgG, IgM, NS1 and PCR). If the dengue diagnosis was confirmed, a medical appointment was scheduled, and another blood sample for confirmatory tests was collected. It was also agreed that in every anniversary of their participation, they would receive another visit for a blood collection for dengue serology, regardless if they had a fever episode or a confirmed dengue diagnosis during the previous year. This article contains the description of the cohort's dataset. It is associated with the article published in Acta Tropica, under the title "A cohort study to assess the incidence of dengue, Brazil, 2014-2018" [4]. The associated article focused on the seroprevalence and incidence of dengue, and explored some associations between both outcomes and some explanatory variables.

Mortality trend due to Hepatitis B and C in the city of São Paulo, 2002-2016.

OBJECTIVE: To describe mortality due to hepatitis B and C as underlying cause in the municipality of São Paulo, verifying the trend of these rates, and to assess the association of these diseases with others, from 2002 to 2016. METHODS: This is a time series study on mortality due to hepatitis B and C according to sex, with data from the Sistema de Informação de Mortalidade (SIM - Mortality Information Sistem). Prais Winsten regression was used in rate trend analysis. RESULTS: The findings of this study showed a trend of decline of mortality from hepatitis B and C in recent years, particularly among males. These infections were important associated causes of liver cell carcinoma and HIV. The proportion of deaths under 70 years of age stands out. CONCLUSIONS: The study provides a baseline for research on mortality trend and the impact of interventions, given the history of expanded detection and supply of treatments, including the most recent antivirals in Brazil, since 2015.

A cohort study to assess the incidence of dengue, Brazil, 2014-2018.

The present cohort study was set up with the aim of determining the incidence of dengue among children and adolescents, from 2 to 16 years of age, living in Araraquara, South-Eastern Brazil, a city classified as a mid-level endemicity location for dengue. Enrollment took place from September 2014 to March 2015. Baseline socio-demographic data were collected, and a blood sample from the participant was drawn, for dengue serology. Families were contacted weekly for fever surveillance. If the child developed fever, a nurse visited the household to collect a blood sample. PCR, NS1 and IgM were used for dengue diagnosis. Parents or legal guardians of participating children provided a written informed consent. 3,514 children and adolescents were enrolled in the cohort. Dengue baseline seroprevalence was 12.2% (95%CI: 11.1 - 13.3). The incidence density of symptomatic dengue was 8.94 per 100 person/years in the first year of follow-up, 0.58 in the second, and 0.19 in the fourth. No cases were confirmed in the third year. Incidence was associated with age, sex, baseline seroprevalence and with living in a house as opposed to an apartment. This study provides relevant information on the epidemiology of dengue in mid-level transmission settings that may be useful to policymakers in the evaluation of control strategies.

Occurrence of hepatitis B in pregnant women and follow-up of exposed children in the State of São Paulo, Brazil, in 2012. / Ocorrência de hepatite B em gestantes e seguimento de crianças expostas no estado de São Paulo, em 2012.

OBJECTIVE: to describe the occurrence of hepatitis B among pregnant women, immunoprophylaxis and vertical and perinatal transmission in children exposed to the virus in the São Paulo state primary care network, Brazil. METHODS: this was a cross-sectional study using prenatal records of pregnant women attending health services between January and June 2012 and a cohort of newborns; the frequencies of the results were described and the estimated occurrence of hepatitis B was calculated. RESULTS: 6,233 pregnant women were included, of whom 53.1% were between 20-29 years old, 58.7% had 8-11 years of schooling, 53.3% were white, and 73.9% lived with a partner; occurrence of hepatitis B was 0.13% (95%CI 0.04; 0.21); of the eight children of mothers with chronic hepatitis B, six had a complete vaccination schedule, and there was no vertical or perinatal transmission. CONCLUSION: there was low occurrence of hepatitis B in pregnant women and absence of vertical or perinatal transmission.

A spatial case-control study on symptomatic and inapparent primary dengue infections in an endemic city in Brazil

ABSTRACT We conducted a spatial case-control study nested in a dengue incidence cohort to explore the role of the spatial and socioeconomic factors in the proportion of symptomatic (cases) and inapparent primary dengue virus infections (controls). Cohort participants were children and adolescents (2 to 16 years of age) at the beginning of the follow-up. Case definitions were, for symptomatic cases, fever plus a positive lab result for acute dengue (NS1, RT-PCR, ELISA IgM/IgG), and for inapparent infection a positive result for dengue IgG (ELISA) in subjects without symptoms and with a previously negative result at baseline. The covariates included sociodemographic factors, residential location, and socioeconomic context variables of the census tracts of residence of cases and controls. We used principal component analysis to reduce the contextual covariates, with the component values assigned to each one based on their residences. The data were modeled in a Bayesian context, considering the spatial dependence. The final sample consisted of 692 children, 274 cases and 418 controls, from the first year of follow-up (2014-2015). Being male, older age, higher educational level of the head of the family and having a larger number of rooms in the household were associated with a greater chance of presenting dengue symptomatic infection at the individual level. The contextual covariates were not associated with the outcome. Inapparent dengue infection has extensive epidemiological consequences. Relying solely on notifications of symptomatic dengue infections underestimates the number of cases, preserves a silent source of the disease, potentially spreading the virus to unaffected areas.

Comparison of clinical tools for dengue diagnosis in a pediatric population-based cohort.

BACKGROUND: We aimed to estimate and compare the ability of clinical tools for dengue diagnosis in a pediatric population. METHODS: We prospectively evaluated episodes of acute febrile syndrome identified during the follow-up of a population-based cohort of children and adolescents residing in a dengue endemic city. We estimated the area under the receiver operating characteristic curve (AU-ROC) for dengue diagnosis of three clinical tools: the summation of manifestations of the WHO case definition, a predefined clinical scale and a logistic regression model obtained in this study. RESULTS: We compared 219 dengue cases (confirmed by laboratory) and 286 patients with other febrile illnesses. In a multiple model, variables independently associated with dengue included the duration of fever, sleepiness and exanthema. Rhinorrhea, cough and minimal leukocyte count were inversely associated with dengue. This model reached an accuracy of 84.2% (for a cut-off of >0.5, sensitivity: 79.5%, specificity: 87.9%, positive predictive value: 83.7%, negative predictive value: 84.6%). The AU-ROC of this model (89.8%) was significantly higher than that obtained with either the predefined scale (82.1%) or the WHO definition manifestations (77%). CONCLUSION: We validated a predefined scale and identified a multiple model suitable for the clinical diagnosis of dengue in the pediatric population.

Seroprevalence of hepatitis E in adults in Brazil: a systematic review and meta-analysis.

BACKGROUND: Hepatitis E virus (HEV) is a member of the Hepeviridae family; it has four main genotypes and one serotype. While genotypes 1 and 2 cause epidemic hepatitis and are transmitted via water and the fecal-oral route, genotypes 3 and 4 are zoonotic. In the various seroprevalence studies of hepatitis E in Brazil, the numbers reported vary widely and are difficult to interpret. The aim of this study was to analyze existing seroprevalence studies of hepatitis E in adults in Brazil. MAIN TEXT: We searched the PubMed, Latin American and Caribbean Health Sciences and Embase databases for studies published from inception to May 12, 2018 concerning infection by HEV in Brazil without time period or language restrictions. We included studies that presented data concerning hepatitis E seroprevalence in adults in Brazil, had a sample size ≥50 patients and whose method used for the detection of anti-HEV was standardized and commercialized. We also evaluated the quality of the articles using a list of criteria that totalized 9 items. Of the 20 studies ultimately analyzed, 10 (50%) were from the southeast region of Brazil, 3 (15%) were from the central-west region, 3 (15%) were from the northern region, 2 (10%) were from the northeast region and 2 (10%) were from the southern region. Regarding the quality evaluation of the studies, the mean score was 5.6 (range: 4-8). The estimated overall seroprevalence of HEV infection in the adult population was 6.0% (95% CI: 5.0-7.0); in subgroup analyses, we observed that the prevalence of anti-HEV antibodies in blood donors was 7.0% (95% CI: 5.0-8.0), whereas in the general population, it was 3.0% (95% CI: 2.0-4.0). CONCLUSIONS: The results of this systematic review indicate that there should be national investment in the prevention of hepatitis E virus infection in Brazil, including the implementation of improvements in basic sanitation and guidance regarding the appropriate handling of animal waste and the optimal cooking of vegetables, meat and their derivatives.