High prevalence of hepatitis A in indigenous population in north Brazil

Objectives

Little is known about hepatitis A virus (HAV) prevalence in indigenous communities. This study aims to evaluate the prevalence of HAV in indigenous community compared to urban population located at Western Amazon in Brazil.

Results

A total of 872 serum samples were obtained from 491 indigenous and 381 non indigenous individuals aging 0 to 90 years. Samples were tested for total and IgM anti-HAV and positive IgM samples were tested for HAV RNA. The overall prevalence of total anti-HAV was 87%, increased according age showing 100% of prevalence in those aging more than 30 years (p < 0.0001) and it was similar among indigenous and urban population. Total anti-HAV prevalence varied between tribes (p < 0.0001) and urban sites (p = 0.0014) and spatial distribution showed high prevalence in homes that received up to 100 dollars. IgM anti-HAV prevalence was 1.7% with predominance in males, those aging more than 41 years. No HAV RNA was detected. In conclusion, high overall anti-HAV prevalence was found in indigenous communities in North Brazil demonstrating the importance of universal vaccination in this group.

Determination of hepatitis B, C and D prevalence among urban and Amerindian populations from the Eastern Brazilian Amazon: a cross sectional study

Background

This study was conducted to determine the prevalence of HBV, HCV, and HDV in urban populations and Amerindians living in the state of Tocantins (Eastern Amazon).

Methods

A total of 948 individuals were recruited in Tocantinopolis city (Tocantins state) of whom 603 were Amerindians (from 6 tribes) and 345 were non-Amerindians (6 urban areas of Tocantinópolis city). Anti-HCV, HBsAg, anti-HBc, anti-HBs, anti-HBc IgM, anti-HBe, HBeAg, and anti-delta antibodies were determined using enzyme immunoassay.

Results

HBV cleared infection (both anti-HBc/anti-HBs+), chronic inactive/immune controlled HBV infection (anti-HBc + only), previous HBV vaccination (anti-HBs + only), active HBV infection (HBsAg+), individuals susceptible to HBV, and anti-HCV reactivity were found in 12.9, 1.8, 27.2, 0.5, 57.7, 1.2% in Amerindians and 12.1, 2.0, 37.1, 0.3, 55.4, 0.3% in non-Amerindians respectively. Out of 139 anti-HBc reactive individuals, 70 were anti-HBe reactive and none presented HBeAg or anti-HBc IgM. Anti-HBc prevalence was associated to older age (p < 0.0001). Overall anti-Delta prevalence was 0.3% and regarding anti-HBc reactive individuals, anti-delta prevalence was 3.4 and 0% in Amerindians and non-Amerindians respectively.

Conclusions

Overall low prevalence of HBV and HCV infection was found in the populations studied, but high HBV and HCV prevalence was observed in Amerindians compared to non-Amerindians suggesting that these individuals have a higher likelihood of acquiring to these infections. Anti-delta antibodies were found among Amerindians from Eastern Amazon suggesting a risk for this population. Of note is that nearly half of Amerindians had no anti-HBs, indicating a need for HBV vaccination campaigns in this population.

Spatial analysis of Tuberculosis in Rio de Janeiro in the period from 2005 to 2008 and associated socioeconomic factors using micro data and global spatial regression models

The present study analyses the spatial pattern of tuberculosis (TB) from 2005 to 2008 by identifying relevant socioeconomic variables for the occurrence of the disease through spatial statistical models. This ecological study was performed in Rio de Janeiro using new cases. The census sector was used as the unit of analysis. Incidence rates were calculated, and the Local Empirical Bayesian method was used. The spatial autocorrelation was verified with Moran's Index and local indicators of spatial association (LISA). Using Spearman's test, variables with significant correlation at 5% were used in the models. In the classic multivariate regression model, the variables that fitted better to the model were proportion of head of family with an income between 1 and 2 minimum wages, proportion of illiterate people, proportion of households with people living alone and mean income of the head of family. These variables were inserted in the Spatial Lag and Spatial Error models, and the results were compared. The former exhibited the best parameters: R2 = 0.3215, Log-Likelihood = -9228, Akaike Information Criterion (AIC) = 18,468 and Schwarz Bayesian Criterion (SBC) = 18,512. The statistical methods were effective in the identification of spatial patterns and in the definition of determinants of the disease providing a view of the heterogeneity in space, allowing actions aimed more at specific populations.

Organização, disponibilização e possibilidades de análise de dados sobre desastres de origem climática e seus impactos sobre a saúde no Brasil

A ocorrência de desastres muitas vezes é associada a processos naturais imprevisíveis. No entanto, a análise de grandes bases de dados permite mostrar tendências sazonais e de longo prazo, bem como padrões e áreas onde se concentram riscos. Neste trabalho é descrito o processo de aquisição e organização de dados sobre desastres, coletados pelos órgãos de defesa civil, e disponibilizados pelo Observatório Nacional de Clima e Saúde. As análises preliminares mostram a concentração de eventos desastres causados por chuvas intensas ao longo da costa brasileira, principalmente durante o verão. As secas apresentam maior duração e extensão, atingindo grande parte do sul e nordeste do país. Estes dados podem ser usados para analisar e monitorar o impacto de eventos climáticos extremos sobre a saúde, bem como seus determinantes de vulnerabilidade e clima.

[The experiment of participatory mapping in order to construct a cartographical alternative to the FHS]

Maps and mapping procedures are useful tools for systematic interpretation and evaluation and for reporting of results to management. Applied to the Family Health Strategy (FHS), these maps permit the demarcation of the territory and the establishment of links between the territory, its population and health services. In this paper the use of maps by the FHS in 17 municipalities in northern and northeastern Brazil is studied and the process of demarcation and digitization of areas with the participation of teams is described. The survey conducted using questionnaires and discussion workshops showed that difficulties still prevail in reconciling the map (drawing) produced at the local level with maps produced by other government sectors. In general, the maps used at local level employ their own references, which prevent the interplay of information with other cartographic documents and their full use as a tool for evaluation and management. The combination of participatory mapping tools, associated with Geographic Information Systems (GIS) applications proposed in this paper, represents an alternative to mapping the territory of operations of FHS teams, as well as a reflection on the concept of territory and operation by the FHS.

Ecological study and risk mapping of leishmaniasis in an endemic area of Brazil based on a geographical information systems approach

Visceral leishmaniasis is a vector-borne disease highly influenced by eco-epidemiological factors. Geographical information systems (GIS) have proved to be a suitable approach for the analysis of environmental components that affect the spatial distribution of diseases. Exploiting this methodology, a model was developed for the mapping of the distribution and incidence of canine leishmaniasis in an endemic area of Brazil. Local variations were observed with respect to infection incidence and distribution of serological titers, i.e. high titers were noted close to areas with preserved vegetation, while low titers were more frequent in areas where people kept chickens. Based on these results, we conclude that the environment plays an important role in generating relatively protected areas within larger endemic regions, but that it can also contribute to the creation of hotspots with clusters of comparatively high serological titers indicating a high level of transmission compared with neighbouring areas.