[Hepatitis B and the human migratory movements in the State of Mato Grosso, Brazil].

Hepatitis B is the main cause of hepatic disease in the Amazon and a biggest problem for its public health. Outbreaks and high prevalence of hepatitis B markers have been reported among immigrants recently arrived in northmost part of the Brazilian State of Mato Grosso. The hepatitis B surface antigen subtypes analysis suggests that the immigrants brought the virus themselves. Likely environmental and behavioral factors have facilitated the hepatitis B spread among these immigrant communities. Recent data show that surveillance and vaccination of immigrants have decreased the incidence of hepatitis B in this region. The increasing number of hepatitis delta cases among hepatitis B carriers from the Northmost part of Mato Grosso State has been detected as a consequence of a increasing contact with neighbor States that present high prevalence of this coinfection.