Lack of evidence for human herpesvirus-8 transmission via blood transfusion in a historical US cohort

Background: Recent studies have found evidence of occasional human herpesvirus (HHV)-8 transmission via blood transfusion. However, because these studies were conducted outside the United States or did not have linked donor-recipient pairs, they have a limited ability to inform US blood-banking policy.

Methods: We investigated HHV-8 transmission via blood transfusion in the United States by conducting HHV-8 serologic testing among participants of the Transfusion-Transmitted Viruses Study (TTVS), who enrolled during the 1970s.

Results: HHV-8 seroprevalence was 2.8% (29/1023) among blood donors, 7.1% (96/1350) among transfusion recipients, 7.7% (46/599) among surgical control patients who did not receive transfusions, and 96.3% (77/80) among control patients with Kaposi sarcoma. One transfusion recipient seroconverted (0.08% [1/1259]), but this patient did not receive any HHV-8-seropositive blood units, suggesting that the infection was not related to blood transfusion. One of the surgical control patients who did not receive transfusions also seroconverted (0.18% [1/556]). Rates of seroconversion were 1.6 per 1000 person-years (95% confidence interval [CI], 0.04-8.9 per 1000 person-years) for the transfusion recipients and 3.6 per 1000 person-years (95% CI, 0.09-20.1 per 1000 person-years) for the surgical control patients who did not receive transfusions (P = .61).

Conclusions: Rates of HHV-8 seroconversion in the transfusion and nontransfusion groups were not statistically different, and the historical nature of the cohort (e.g., before leukoreduction) suggests that any current transmission via blood transfusion is rare.