Investigation of an outbreak of hepatitis A in Irish haemophilia A patients.

Since 1990, Irish haemophilia A patients have been treated with solvent-detergent(SD)-treated virally inactivated high-purity factor VIII concentrate prepared from plasma from Irish voluntary non-remunerated donors. In 1992, 13 haemophilia A patients developed clinical hepatitis A and a further 17 patients showed serological evidence of recent infection by hepatitis A. All but 3 of these patients had had recent exposure to SD-treated product. A case-control study is underway to determine whether these cases represent transmission through product or environmentally acquired hepatitis A.