The Incidence of Post-Transfusion Hepatitis

To the Editor: We question the validity of the conclusion of Donahue et al. (Aug. 6 issue)¹ that testing for non-A, non-B hepatitis surrogate markers caused a reduction in the incidence of post-transfusion hepatitis C virus (HCV) infection. Their data are also consistent with the hypothesis that there is only a temporal association between the institution of surrogate-marker testing and the reduction in the incidence of post-transfusion hepatitis between 1985 and 1990. Such a temporal association could be due to the concurrent institution of changes in blood-screening and transfusion practices. Whether the observed differences are causally or temporally associated could…