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.

Population-based multicentric survey of hepatitis B infection and risk factor differences among three regions in Brazil.

Alternative vaccine delivery methods

Brazil was formerly considered a country with intermediate hepatitis B endemicity, with large heterogeneity between Brazilian regions and areas of high prevalence, especially in the Amazon basin. Systematic vaccination of children was initiated in 1998. Between 2004 and 2009, a large population-based study reported decreased prevalence in all regions of Brazil. This review analyzed the current hepatitis B epidemiological situation in Brazil through a systematic search of the scientific literature in MEDLINE, LILACS, and CAPES thesis database, as well as disease notifications to the Information System for Notifiable Diseases. The search strategy identified 87 articles and 13 theses, resulting in 100 total publications. The most recent results indicate reduced hepatitis B prevalence nationwide, classifying Brazil as having low endemicity. Most studies showed HBV carrier prevalence less than 1%. However, there are still isolated regions with increased prevalence, particularly the Amazon, as well as specific groups, such as homeless people in large cities and isolated Afro-descendant communities in the center of the country. This review alsao detected successful vaccination coverage reported in a few studies around the country. The prevalence of anti-HBs alone ranged from 50% to 90%. However, isolated and distant localities still have low coverage rates. This review reinforces the downward trend of hepatitis B prevalence in Brazil and the need to intensify vaccination strategies for young people and adults in specific regions with persisting higher HBV infection prevalence.

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Distribution of hepatitis B infection in Brazil: the epidemiological situation at the beginning of the 21 st century.

OBJETIVO: Tracar um panorama da infeccao por hepatite B no Brasil, na Regiao Sul e no Estado de Santa Catarina para o periodo de 1996 a 2002, considerando aspectos epidemiologicos como faixa etaria. FONTE DOS DADOS:Os dados foram obtidos a partir de levantamento bibliografico e consulta a Secretaria de Vigilância Epidemiologica do Estado de Santa Catarina e a Fundacao Nacional de Saude (FUNASA). RESULTADOS: No Brasil, de 1996 a 2000, a hepatite B foi o segundo tipo de hepatite viral mais prevalente (25%), tendo sido a hepatite A lider em casos (43%). Em Santa Catarina houve predominio de hepatite B em relacao as outras hepatites de 1997 a 2001. O sexo mais atingido pela hepatite B foi o masculino e a maior incidencia de hepatite B foi observada na faixa etaria dos 20 aos 49 anos para Santa Catarina e acima dos 30 anos para o Brasil. O Sul foi a regiao brasileira que apresentou a maior incidencia de hepatite B no periodo de 1997 a 1999. Em Santa Catarina, o maior numero de casos entre 1996 e 2002 ocorreu na macrorregiao sul, seguida das macrorregioes nordeste e extremo oeste. CONCLUSOES: Ainda e crescente o numero de casos de hepatite B no Brasil e deve-se considerar que a subnotificacao pode afetar os numeros apresentados. Em todo o Brasil, a vacinacao deve ser estendida a adolescentes em regioes de prevalencia moderada a alta

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Panorama da hepatite B no Brasil e no Estado de Santa Catarina

Surface antigen negative hepatitis B virus (HBV) infection was evaluated in Venezuela, by molecular characterization of blood samples positive for antibodies to core antigen (anti-HBc) and negative for surface antigen (HBsAg) in blood donors (residual infections). HBV DNA was found in 11/258 samples (4.3%), and was significantly associated with high levels of anti-HBc antibodies (>25 UI/ml, P < 0.05), while no correlation was found between the presence of HBV DNA and the levels of anti-HBs. Synonymous and non-synonymous mutations were found in the HBV surface region (but not vaccine escape mutants) and in the precore/core region (precore mutants in 2/7 samples and 33-45 bp deletions near the N-terminal core region in 4/19 samples). While HBV genotype F prevails among HBsAg positive samples from blood donors in Venezuela, residual infection isolates were mainly genotypes A and D. Phylogenetic analysis of viral surface and core region revealed discrepancies in genotype designation in 6/9 samples, suggesting the presence of mixed infection or recombination. In conclusion, HBV residual infection in Venezuela does not seem to be frequently observed in HBV genotype F. This type of infection is frequently associated with variants exhibiting mutations in the surface gene that might be affecting the correct recognition by commercial tests, with precore mutants and with core internal deletions. These variants do not seem to cause severe liver disease, and on the contrary, were found circulating at low viremia.

Molecular and serological evaluation of surface antigen negative hepatitis B virus infection in blood donors from Venezuela

Objetivo. Realizar um inquerito soro-epidemiologico sobre infeccao pelo virus da hepatite B em um municipio do medio-norte do Estado de Mato Grosso, que corresponde a regiao limitrofe entre o cerrado e a bacia amazonica. Metodos. A amostra incluiu familias escolhidas aleatoriamente na sede do municipio, assim como toda a populacao de uma comunidade rural, totalizando 754 individuos. A idade variou de 2 a 79 anos. Os participantes foram entrevistados e tiveram amostras de sangue colhidas para pesquisa de marcadores do virus da hepatite B por metodo imunoenzimatico. Resultados. A infeccao pelo virus da hepatite B foi constatada em 31% da amostra, sendo 3% positivos para o HBsAg. Os 149 (20%) com historia de vacinacao e anti-HB positivo isoladamente foram considerados respondedores a vacina. As variaveis associadas a exposicao ao virus da hepatite B por analise multivariada foram: ja ter iniciado atividade sexual, ter sido vacinado com pistola pressurizada contra febre amarela (entre aqueles com menos de 20 anos) e ser migrante oriundo do Sul do Brasil (individuos com mais de 20 anos). A cobertura vacinal foi baixa entre individuos com mais de 10 anos de idade. O maior numero de suscetiveis (74%) foi encontrado na faixa dos 11 aos 20 anos. Conclusoes. No Brasil, a vacinacao contra a hepatite B deve ser estendida quanto antes aos adolescentes nas regioes de baixa a moderada prevalencia. E provavel que os dados obtidos no presente estudo possam ser extrapolados para outras regioes da America Latina com padrao epidemiologico semelhante.

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Graciela A. Espírito Santo

Papers

Prevalência e fatores associados a marcadores do vírus da hepatite B em população rural do Brasil central