Transmission of HIV by Transfusion of Screened Blood

Abstract

Despite evidence demonstrating the effectiveness of donor-screening procedures for HIV type 1 (HIV-1),^{1 , 2} there remains considerable concern among members of the general public about the safety of the blood supply. Both indirect and direct estimates of the risk of transfusion-transmitted HIV-1 infection have been reported. Cumming et al.¹ based their estimate of a risk of 0.00065 percent (1 in 153,000) on test results from donors at 41 regional blood centers in the United States and on the probability of a seropositive donation during an eight-week "window period." We recently reported the interim results of a large, prospective seroepidemiologic study of patients undergoing cardiac surgery in hospitals in Baltimore and Houston.³ A single seroconversion to HIV-1 positivity was found among 4163 patients who had received 36,282 units of blood or blood components — equivalent to a risk of 0.0028 percent (1 in 36,282) per unit given in transfusion, with the upper limit of the 95 percent confidence interval equal to 0.013 percent. The serum samples were collected before and approximately six months after surgery.