Clinical, epidemiological and prognostic aspects of hepatitis "non-A, non-B"--a comparison with hepatitis A and B.

Sera of 480 hospitalized hepatitis patients were tested for hepatitis B surface antigen (HBsAg), antibody to HBsAg (anti-HBs) and to hepatitis B core antigen (anti-HBc), antibody to hepatitis A virus (anti-HAV) and anti-HAV of IgM-class. Serological markers indicating hepatitis A infection were found in 107 (22.3%) and markers indicating hepatitis B in 297 patients (61.9%), while 63 patients (13.1%) were classified as hepatitis type "non-A, non-B". The latter group mainly comprised drug addicts (50.8%), cases of post-transfusion hepatitis (11.1%) and patients without obvious hepatitis exposure (28.6%). In spite of these epidemiological similarities to hepatitis B, the maximum levels of serum alanine aminotransferase and bilirubin were comparable to those in patients with hepatitis A and significantly lower than in hepatitis B infection. Chronic hepatitis developed in 7.1% of the "non-A, non-B" patients, a figure close to that reported for hepatitis B.