The HBsAg-Positive Patient: Implications and a Guide to Management.

Following infection with hepatitis B virus (HBV), hepatitis B surface antigen (HBsAg) is detectable in the serum before liver function tests become abnormal and before development of clinical features of hepatitis; HBsAg tests usually become negative shortly after illness subsides. Screening individuals such as volunteer blood donors for HBsAg occasionally reveals apparently healthy people who are persistent carriers of HBsAg; the majority have no laboratory evidence of hepatitis whereas others have biochemical or histologic findings of chronic liver disease.