HEPATITIS-B VIRUS-INFECTION IN IMMIGRANTS TO THE SOUTHERN BRAZILIAN AMAZON

To identify epidemiological patterns and risk factors associated with hepatitis E virus (HBV) infection in the southern Brazilian Amazon, a survey was performed in the county of Terra Nova do Norte in the north ern part of the state of Mate Grosso. The population consists mainly o f immigrants from the southern part of Brazil, where HBV prevalence is low. A random sample (n=783) of the population was interviewed and te sted for HBV markers. The overall prevalence of HBV infection was 54.7 %. There were 31 hepatitis B surface antigen (HBsAg) carriers (3.9%), with a low rate of HBV e antigen positivity, and none with anti-hepati tis D virus. Subtypes ayw3 and ayw2 of HBsAg were predominant, suggest ing that the immigrants carried HBV from their original region to the Amazon. Clustering of HBV infection within families was found.The asso ciation between HBV markers and having lived in a gold-miners' camp, e ven after adjusting for confounders, indicated that the gold-miners ma y play a role in HBV spread in areas of the Amazon where gold prospect ing occurs.