Prevalência de infecção chagásica em doadores de sangue no estado de Pernambuco, Brasil / The prevalence of chagasic infection among blood donors in the State of Pernambuco, Brazil

A doença de Chagas é uma infecção sistêmica de evolução crônica cujo agente etiológico é o parasita Trypanosoma cruzi. O último relato encontrado sobre a soroprevalência da doença em doadores de sangue realizado na capital pernambucana, Recife, data de 1970, onde foi encontrada uma prevalência de 4,4 por cento em doadores de um hospital local. Devido à falta de informações divulgadas sobre a infecção por T. cruzi e sendo Pernambuco uma região endêmica para esta enfermidade, o presente estudo se propôs a analisar o perfil dos doadores de sangue do Hemocentro de Pernambuco (Hemope), que apresentaram reatividade para doença de Chagas, no período de 2002 a 2007. O perfil dos doadores inaptos foi avaliado de acordo com gênero, idade e procedência segundo as mesorregiões de Pernambuco. Foi encontrada uma prevalência de 0,17 por cento para doença de Chagas e 6,89 por cento das bolsas descartadas deveram-se a essa reatividade. Em relação ao gênero dos doadores, foi significativamente maior a contribuição dos homens (p<0,0001). A faixa etária de 18-30 anos apresentou menor quantidade de sorologias reativas (20,21 por cento). Foi verificado também que, na Região Metropolitana do Recife, a quantidade de reações inconclusivas foi estatisticamente maior que a quantidade de sorologias reagentes (p=0,0440). Desta forma, estudos epidemiológicos fornecem dados importantes no sentido de se avaliar diretamente o risco de transmissão de uma doença por transfusão sanguínea e permitem que também em regiões endêmicas se avalie a eficácia das medidas para o controle vetorial.

Chagas disease is a systemic infection with a chronic onset transmitted by Trypanosoma cruzi. The last study conducted in Recife, capital of Pernambuco state, was carried out during 1970. At that time a prevalence of 4.4 percent was found among blood donors of a local hospital. Due to the lack of epidemiology data on T. cruzi infection and as Pernambuco is an endemic region, the present study describes the profile of blood donors who presented reactivity for Chagas disease during the period of 2002 to 2007 in the state's blood bank (Hemope). The profile of unsuitable donors was evaluated according to gender, age and according to the meso-regions of Pernambuco. A prevalence of 0.17 percent was found for Chagas disease, whereas 6.89 percent of the rejected blood bags were due to this reactivity. As far as gender is concerned, the reactivity of men was higher than that of women (p<0.0001). Additionally, the age group between 18-30 years was less infected (20.21 percent). On analyzing the reactivity in each one of the meso-regions of the state, it was found that, in the Metropolitan Region of Recife, the number of inconclusive reaction cases was statistically higher than the number of reactive serology cases (p=0.0440). Thus, epidemiological studies provide important data to indirectly evaluate the risk of blood-borne diseases and allow indirect evaluation of the effectiveness of vectorial control measures in endemic regions.

Seroprevalence of hepatitis B and C in Brazilian army conscripts in 2002: a cross-sectional study

Hepatitis B and C constitute important public health problems worldwide. In Brazil, studies on prevalence of viral hepatitis have local and regional characteristics; consequently it is difficult to define the national epidemiological situation. Our objective was to evaluate the seroprevalence of hepatitis B and C in conscripts of the Brazilian Army. A transversal study among males aged 17 to 22 years was conducted nationwide. After informed consent, each volunteer filled in a social-behavioral questionnaire and had blood drawn to test for HBsAg and anti-HCV. A total of 7,372 volunteers were evaluated in the second half of 2002. The prevalence of HBsAg was 2.6 percent (95 percent confidence interval: 2.2, 3.0) and that of anti-HCV was 1.5 percent (95 percent confidence interval: 1.2, 1.8). A wide variation among macro regions and states in the same region was observed for both markers. In conclusion, although this population theoretically had a low risk for HBV and HCV infection, these results are higher than expected for this age range. These findings may indicate a change in the pattern of HBV and HCV transmission in Brazil. Due to the different dynamics of these epidemics, further studies are warranted to confirm these apparent trends.

Serodiagnosis of Trypanosoma cruzi infection using the new particle gel immunoassay - ID-PaGIA Chagas

The ID-Chagas test is a particle gel immunoassay (PaGIA). Red coloured particles are sensitised with three different synthtic peptides representing antigen sequences of Trypanosoma cruzi: Ag2, TcD and TcE. When these particles are mixed with serum containing specific antibodies, they agglutinate. The reaction mixture is centrifuged through a gel filtration matrix allowing free agglutinated particles to remain trapped on the top or distributed within the gel. The result can be read visually. In order to investigate the ability of the ID-PaGIA to discriminate negative and positive sera, 111 negative and 119 positive, collected in four different Brazilian institutions, were tested by each of the participants. All sera were previously classified as positive or negative according to results obtained with three conventional tests (indirect immunofluorescence, indirect hemaglutination, and enzyme linked immunosorbent assay). Sensitivity rates of ID-PaGIA varied from 95.7 per cent to 97.4 per cent with mean sensitivity of 96.8 per cent and specificity rates varied from 93.8 to 98.8 per cent with mean specificity of 94.6 per cent. The overall Kappa test was 0.94. The assay presents as advantages the simplicity of operation and the reaction time of 20 min. In this study, ID-PaGIA showed to be highly sensitive and specific.

Estudo multicêntrico: avaliaçäo do desempenho de conjuntos diagnósticos de hemaglutinaçäo indireta, disponíveis no Brasil, para o diagnóstico sorológico da infecçäo pelo Trypanosoma cruzi / Multicentric study: evaluation of the performance of kits for indirect hemagglutination available in Brazil for the serological diagnosis of the infection by Trypanosoma cruzi

Por iniciativa da Coordenaçäo do Sistema de Laboratórios de Saúde Pública (COLAB), da Fundaçäo Nacional da Saúde instituiu um comitê composto por diferentes membros da comunidade científica e de serviços, com a finalidade de avaliar os conjuntos diagnósticos (CDs), concretizados no Brasil, para o diagnóstico sorológico da tripanosomíase americana (doença de Chagas). Cinco laboratórios avaliaram 11 CDs para o teste de hemaglutinaçäo indireta, disponíveis no mercado, seguindo as instruçöes de cada fabricante. Cada CD foi testado através dos resultados obtidos num painel com 87 soros (52 reagentes e 35 näo reagentes), provenientes das sorotecas dos mesmos laboratórios participantes da avaliaçäo. O critério para reatividade adotado nas amostras do painel baseou-se nos resultados obtidos com os testes imunoenzimático (ELISA) e de imunofluorescência indireta (diluiçäo de 1:40)...