BackgroundHepatitis 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.MethodsThe 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.ResultsThe 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.ConclusionsThe 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.

This multicentric population-based study in Brazil is the first national effort to estimate the prevalence of hepatitis B (HBV) and risk factors in the capital cities of the Northeast, Central-West, and Federal Districts (2004-2005). Random multistage cluster sampling was used to select persons 13-69 years of age. Markers for HBV were tested by enzyme-linked immunosorbent assay. The HBV genotypes were determined by sequencing hepatitis B surface antigen (HBsAg). Multivariate analyses and simple catalytic model were performed. Overall, 7,881 persons were included; < 70% were not vaccinated. Positivity for HBsAg was less than 1% among non-vaccinated persons and genotypes A, D, and F co-circulated. The incidence of infection increased with age with similar force of infection in all regions. Males and persons having initiated sexual activity were associated with HBV infection in the two settings; healthcare jobs and prior hospitalization were risk factors in the Federal District. Our survey classified these regions as areas with HBV endemicity and highlighted the risk factors differences among the settings.

A population-based hepatitis survey was carried out to estimate the prevalence of hepatitis B virus (HBV) infection and its predictive factors for the state capitals from the north, south, and southeast regions of Brazil. A multistage cluster sampling was used to select, successively, census tracts, blocks, households, and residents in the age group 10–69 years in each state capital. The prevalence of hepatitis B surface antigen (HBsAg) was lower than 1% in the north, southeast, and south regions. Socioeconomic condition was associated with HBV infection in north and south regions. Variables related to the blood route transmission were associated with HBV infection only in the south whereas those related to sexual behavior were associated with HBV infection in the north and south regions. Drug use was associated in all regions, but the type of drug differed. The findings presented herein highlight the diversity of the potential transmission routes for hepatitis B transmission in Brazil. In one hand, it reinforces the importance of national control strategies of large impact already in course (immunization of infants, adolescents, and adults up to 49 years of age and blood supply screening). On the other hand, it shows that there is still room for further control measures targeted to different groups within each region.

A population-based survey to provide information on the prevalence of hepatitis viral infection

Background The objectives were to estimate the prevalence of hepatitis A among children and adolescents from the Northeast and Midwest regions and the Federal District of Brazil and to identify individual-, household- and area-levels factors associated with hepatitis A infection.Methods This population-based survey was conducted in 2004–2005 and covered individuals aged between 5 and 19 years. A stratified multistage cluster sampling technique with probability proportional to size was used to select 1937 individuals aged between 5 and 19 years living in the Federal capital and in the State capitals of 12 states in the study regions. The sample was stratified according to age (5–9 and 10- to 19-years-old) and capital within each region. Individual- and household-level data were collected by interview at the home of the individual. Variables related to the area were retrieved from census tract data. The outcome was total antibodies to hepatitis A virus detected using commercial EIA. The age distribution of the susceptible population was estimated using a simple catalytic model. The associations between HAV infection and independent variables were assessed using the odds ratio and corrected for the random design effect and sampling weight. Multilevel analysis was performed by GLLAMM using Stata 9.2.Results The prevalence of hepatitis A infection in the 5–9 and 10–19 age-group was 41.5 and 57.4%, respectively for the Northeast, 32.3 and 56.0%, respectively for the Midwest and 33.8 and 65.1% for the Federal District. A trend for the prevalence of HAV infection to increase according to age was detected in all sites. By the age of 5, 31.5% of the children had already been infected with HAV in the Northeast region compared with 20.0% in the other sites. By the age of 19 years, seropositivity was ∼70% in all areas. The curves of susceptible populations differed from one area to another. Multilevel modeling showed that variables relating to different levels of education were associated with HAV infection in all sites.Conclusion The study sites were classified as areas with intermediate endemicity area for hepatitis A infection. Differences in age trends of infection were detected among settings. This multilevel model allowed for quantification of contextual predictors of hepatitis A infection in urban areas.

BackgroundThis study aimed to identify the transmission pattern of hepatitis A (HA) infection based on a primary dataset from the Brazilian National Hepatitis Survey in a pre-vaccination context. The national survey conducted in urban areas disclosed two epidemiological scenarios with low and intermediate HA endemicity.MethodsA catalytic model of HA transmission was built based on a national seroprevalence survey (2005 to 2009). The seroprevalence data from 7,062 individuals aged 5–69 years from all the Brazilian macro-regions were included. We built up three models: fully homogeneous mixing model, with constant contact pattern; the highly assortative model and the highly assortative model with the additional component accounting for contacts with infected food/water. Curves of prevalence, force of infection (FOI) and the number of new infections with 99% confidence intervals (CIs) were compared between the intermediate (North, Northeast, Midwest and Federal District) and low (South and Southeast) endemicity areas. A contour plot was also constructed.ResultsThe anti- HAV IgG seroprevalence was 68.8% (95% CI, 64.8%–72.5%) and 33.7% (95% CI, 32.4%–35.1%) for the intermediate and low endemicity areas, respectively, according to the field data analysis. The models showed that a higher force of infection was identified in the 10- to 19-year-old age cohort (∼9,000 infected individuals per year per 100,000 susceptible persons) in the intermediate endemicity area, whereas a higher force of infection occurred in the 15- to 29-year-old age cohort (∼6,000 infected individuals per year per 100,000 susceptible persons) for the other macro-regions.ConclusionOur findings support the shift of Brazil toward intermediate and low endemicity levels with the shift of the risk of infection to older age groups. These estimates of HA force of infection stratified by age and endemicity levels are useful information to characterize the pre-vaccination scenario in Brazil.

BackgroundHepatitis 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 textWe 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).ConclusionsThe 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.Electronic supplementary materialThe online version of this article (10.1186/s40249-018-0514-4) contains supplementary material, which is available to authorized users.

A reformulação do sistema de saúde, que vem ocorrendo em nível nacional e particularmente no Estado de São Paulo, tem motivado revisões do processo de planejamento, criando novas necessidades na área de informações. A criação do Sistema Único de Saúde e o processo de municipalização retomaram as propostas de integração das atividades curativas e preventivas, bem como a estruturação de sistemas de saúde regionalizados e hierarquizados. Nesse contexto, surgem como áreas de conhecimento, de particular interesse, o perfil de morbidade populacional e o padrão de utilização de serviços de saúde. As respostas a essas necessidades podem ser dadas por inquéritos domiciliares de saúde. Descreve-se a metodologia utilizada em um inquérito domiciliar realizado em municípios da região sudoeste da Área Metropolitana de São Paulo, SP, Brasil, no período de julho de 1989 a junho de 1990. Esse inquérito apresenta algumas características metodológicas específicas, entre elas o processo amostral utilizado, que definiu domínios para a amostra que permitiram análise de grupos pouco representados na população, como os menores de um ano de idade e a população idosa, bem como o ajuste da amostra a partir dos dados censitários de 1991.