Hepatitis B marker seroprevalence and vaccination coverage in adolescents in the City of Itajaí, State of Santa Catarina, Southern Brazil, in 2008 / Soroprevalência de marcadores da hepatite B e cobertura de vacinação em adolescentes no município de Itajaí, Estado de Santa Catarina Sul do Brasil, em 2008

INTRODUCTION: Hepatitis B infection constitutes an important cause of morbidity and mortality worldwide. In Brazil, however, the current epidemiological situation is not clear. Considering the importance of establishing this prevalence, the aim of this study was to determine the prevalence of HBV markers in voluntary adolescents, junior high (secondary school) students, in the City of Itajaí, State of Santa Catarina, Brazil. METHODS: A seroepidemiological, transverse study was conducted with 353 randomly chosen adolescents from elementary school in 2008. Blood samples were analyzed for HBsAg, anti-HBc and anti-HBs. All analyses were conducted by automated microparticle enzyme immunosorbent assay (Abbott®, AxSYM system, Deerfield, IL, USA), according to the manufacturer's instructions. RESULTS: The prevalence of HBsAg was 0.6% (CI 95% 0.1 - 2.0), that of anti-HBc was 1.1% (CI 95% 0.3 - 2.9) and that of detectable anti-HBs was 83.6% (CI 95% 79.3 - 87.3). Hepatitis B vaccination coverage was 97.5% (CI 95% 95.2 - 98.8). CONCLUSIONS: These results demonstrate the success of the vaccination program against hepatitis B in the region studied and indicate that prevention strategies must be maintained and, if possible, expanded to contribute to the establishment of positive prevalence rates in all age groups.

INTRODUÇÃO: A hepatite B constitui uma causa relevante de morbidade e mortalidade em todo o mundo. No Brasil, entretanto, a situação epidemiológica atual não é claramente conhecida. Considerando-se a importância do estabelecimento de tal prevalência, o objetivo deste estudo foi determinar a prevalência dos marcadores de HBV em adolescentes voluntários, estudantes do ensino fundamental na Cidade de Itajaí, Santa Catarina, Brasil. MÉTODOS: Trata-se de um estudo soroepidemiológico, transversal, conduzido com 353 adolescentes do ensino fundamental, randomicamente selecionados, em 2008. As amostras de sangue foram analisadas quanto à presença dos marcadores HBsAg, anti-HBc e anti-HBs. Todas as análises foram conduzidas em ensaio imunoenzimático de micropartículas automatizado (Abbott®, AxSYM system, Deerfield, IL, EUA), de acordo com as instruções do fabricante. RESULTADOS: A prevalência do HBsAg foi de 0,6% (CI 95% 0,1 - 2,0), do anti-HBc foi de 1,1% (CI 95% 0,3 - 2,9) e de títulos detectáveis de anti-HBs foi de 83,6% (CI 95% 79,3 - 87,3). A cobertura vacinal nos adolescentes estudados foi de 97,5% (CI 95% 95,2 - 98,8). CONCLUSÕES: Estes resultados demonstram o sucesso do programa de vacinação contra a hepatite B na região estudada e indicam que as estratégias de prevenção devem ser mantidas e, se possível, expandidas para que contribuam no estabelecimento de taxas de prevalência positivas em todas as faixas etárias.

Comparative evaluation of different immunoassays for the detection of Taenia solium cysticercosis in swine with low parasite burden

Seven swine were experimentally infected with Taenia solium eggs and blood samples from each animal were periodically collected. At the end of the experiment (t140) the animals did not show clinical aspects of cysticercosis or parasites in tongue inspection. All animals were slaughtered and cut into thin slices in searching for cysts. The number of cysts found in each animal varied from 1 to 85. Enzyme-linked immunosorbent assay (ELISA) tests for antibody (Ab) detection and for antigen (Ag) detection were performed, which presented respectively 71 and 57 percent of positivity. By immunoblot (IB), using 18/14(T. crassiceps Ag) or lentil-lectin-purified glycoproteins from T. solium Ag (LLGP) as Ag, five (71 percent) and six (86 percent) animals were positive, respectively. The association between Ag-ELISA with any IB (18/14 or LLGP) allowed the detection of all animals at 140 days post-experimental infection (days p.e.i.). The use of IB 18/14 combined to the Ag-ELISA allowed the detection of all animals since 70 days p.e.i., and the association between IB LLGP and Ag-ELISA allowed the detection of all animals since 112 days p.e.i. While all animals could be considered healthy by conventional screening tests, the use of immunoassays for detecting Ab and Ag showed better accuracy; therefore it would be more useful than usual clinical examination for screening cysticercosis in slightly infected pigs.