Subtypes of HBsAg among hepatitis patients.

Serum samples from 94 Finnish hospital patients with hepatitis B were investigated for subtypes of HBsAg. Subtype ay predominated in patients with acute hepatitis (77%). All drug abusers had the ay subtype. Of 11 patients with chronic liver disease, 10 (91%) had the ad subtype. Five of 7 hepatitis cases associated with blood transfusion had subtype ay, although this determinant has not been detected among Finnish non-paid blood donors. These results suggest that blood donors who incubate hepatitis B (HBsAg not yet detectable) are an important source of transfusion hepatitis.