ABSTRACT
Of 33 patients with acute hepatitis in Malawi; 21 had infection by hepatitis-B virus (HBV); five by hepatitis-A virus (HAV) and seven; who had no markers of current HBV or HAV infections; were probably infected by the agent(s) of non-A; non-B; hepatitis. 87 of 88 sera from persons without liver disease contained antibody to HAV and 49 antibody to hepatitis-B surface antigen (anti-HBs) (six were positive for hepatitis-B surface antigen). The diagnosis of recent infection by HAV was made by detecting HAV-specific IGM in single serum samples and; although such tests showed that HAV caused acute hepatitis; its absence in patients with chronic liver disease suggests that; unlike HBV; infection by HAV does not play a role in chronic liver disease in Malawi. Anti-hepatis-B core antigen (anti-HBc)-specific IgM was detected in 19 of 21 patients with acute HBV infection; in three of five HbsAg-positive patients with cirrhosis; but in none of five Hbs Ag-positive patients with hepatoma