[The evolution of knowledge about viral hepatitis in Amazon region: from epidemiology and etiology to the prophilaxy].

Since the 1950 years a disease similar to yellow fever but thought to be a new disease with unknown etiology has been described to health and researcher authorities. This disease occurs in Jurua, Purus and Madeira Rivers valleys. It is feared by local people by its high lethality. It is clinically a hepato-encephalopathy (Average survival time of 5-6 days) About 90% of sick people with typical symptoms go to death. The disease is popularly known as black fever of Lábrea and by pathologist as Lábrea hepatites after the city where the first cases were observed. The specific histopatologic picture of vesicular degeneration of hepatocytes like spider cells motivate the local pathologist to think as a new disease: Lábrea hepatitis. The finding of HBsAg and marker of hepatites D virus (HDV) in the serum motivate the researchers to think the disease as a superinfection of HDV in chronic carriers of HBV. In absence of a specific vaccine against HDV, the vaccine against HBV, must be given soon after the birth is the recommended prevention.