Hepatitis A among persons with hemophilia who received clotting factor concentrate--United States, September-December 1995.

Hepatitis A outbreaks associated with receipt of clotting factor concentrate previously have been recognized in Europe but not in the United States (1-5). During September-November 1995, three cases of hepatitis A in recipients of Alphanate factor VIII concentrate (Alpha Therapeutic Corporation, Los Angeles, California) from lot number AP5014A were reported to CDC. On December 8, the manufacturer voluntarily withdrew Alphanate lot number AP5014A from the market. In addition, one case of hepatitis A in a recipient of AlphaNine S-D factor IX concentrate (Alpha Therapeutic Corporation) has been reported and is under investigation. On January 11, 1996, the manufacturer voluntarily withheld four lots of AlphaNine S-D from further distribution as a precautionary measure. This report describes these four cases, summarizes the status of the investigation of the cases, and provides guidelines for testing and reporting of patients who received these products.