The seroepidemiological pattern of acute viral hepatitis. An epidemiological study on viral hepatitis in the Hannover region.

The natural incidence of the etiologically distinct types of viral hepatitis was determined by investigating acute phase sera of symptomatic hepatitis cases occuring in the Hannover area in 1975 for the presence of hepatitis B surface antigen, antibodies to hepatitis A, hepatitis B core and surface antigens, and by measuring the IgM serum levels. Fourteen different seroepidemiologic patterns were recognized. Although there was a high prevalence of hepatitis A antibody in the population, the frequency of hepatitis A was low (n = 56) suggesting that the hepatitis A virus does not play a major role in symptomatic hepatitis in the Hannover area at present. Spread of the hepatitis A virus was mostly associated with person-to-person contact or tourist travel in southern Europe. Hepatitis B was the predominant type of hepatitis (n = 211). Hepatitis non-A, non-B was observed infrequently (n = 62). A high percentage of patients with hepatitis B and hepatitis non-A, non-B reported parenteral exposure to potentially contaminated materials. No other findings, however, suggested an infectious etiology of hepatitis non-A, non-B.