Abstract

BRAGA, Wornei Silva Miranda et al. Prevalence of hepatitis B virus (HBV) and hepatitis D virus (HDV) Infections in Lábrea, Purus River Basin, Western Brazilian Amazon. Epidemiol. Serv. Saúde [online]. 2004, vol.13, n.1, pp.35-46. ISSN 1679-4974.  http://dx.doi.org/10.5123/S1679-49742004000100005.

This study estimates the prevalence of hepatitis B virus (HBV) and hepatitis Delta virus (HDV) infections in the city of Lábrea, Western Amazon, Brazil, 11 years after the introduction of the HBV vaccination program in this region. The prevalence rates of HBV infection and HBV surface antigen (HbsAg) carriage were 49,9% and 3,3% respectively. HBV infection shows a medium endemicity pattern, low potential of infectivity and subclinical course of infection. Transmission may be more intense in children between 6 and 12 years of age, and among young adults, probably by perinatal or horizontal transmission within households or by sexual transmission, with a moderate risk for the development of chronic liver disorders. Interfamilial dissemination may be of great importance. HDV was found in 30% of HBsAg carriers, occurred with a history of acute hepatitis, and in HBV carriers was associated with biochemical signs of liver damage, demonstrating the importance of these two viruses as agents of liver disease in this population. We identified a significant reduction in the prevalence rates of HBV infection compared to those reported before the introduction of HBV vaccine, at least five times less for the prevalence of HBsAg, despite the failures detected in the protection of susceptible individuals.

Keywords : hepatitis B; hepatitis Delta; prevalence; Amazon.

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