Epidemiology and clinical characteristics of acute hepatitis types A, B, and non-A non-B.

A consecutive series of 115 patients hospitalized with acute viral hepatitis in Copenhagen was studied for serological markers for hepatitis A and B virus. Thirty-nine patients had type B, 66 had type A, 3 had both type A and B, and 7 had type non-A non-B. Of the patients 81% were between 15 and 40 years of age, and there was a dominance of males due to an overrepresentation of homosexual males (30%) in both the A and B group. The main type of exposure to hepatitis type A was travel to foreign countries (53%), and for type B it was drug addiction (41%). In types A and B the duration of jaundice was positively correlated to the age of the patients but did not vary with sex or type of exposure. There was no difference in maximum alanine aminotransferase levels between the groups, but maximum bilirubin levels were lower for the type A group. Patients with hepatitis type A had a higher level of IgM than those with type B and with type non-A and non-B. We conclude that both clinically acute hepatitis type A and type B occur mainly in young adults and that foreign travel, drug addiction, and homosexuality increase the risk of getting acute hepatitis.