Possible transmission of human herpesvirus-8 by blood transfusion in a historical United States cohort

BACKGROUND: Transmission of human herpesvirus-8 (HHV-8) by blood transfusion in the United States appears plausible but has not been demonstrated. The objective of this study was to evaluate evidence of HHV-8 transmission via blood transfusion. STUDY DESIGN AND METHODS: Serum specimens were collected before and 6 months after surgery from 406 patients who enrolled in the Frequency of Agents Communicable by Transfusion study (FACTS) in Baltimore, Maryland, from 1986 to 1990. The change in HHV-8 serostatus was measured by a lytic-antigen immunofluorescence assay. RESULTS: Of the 284 patients who were initially HHV-8-seronegative and who received transfusions, 2 seroconverted, 1 with a postsurgery antibody titer of 1:160 and the other with a titer of 1:1280. These patients received 12 and 13 units of blood, respectively. None of the HHV-8-seronegative patients who did not receive transfusions seroconverted. If seroconversion was caused by transfused blood, the transmission risk per transfused component was 0.082 percent. CONCLUSIONS: This is the first report suggesting transmission of HHV-8 via blood components in the United States. Because linked donor specimens were not available, other routes of transmission cannot be excluded; however, the evidence is consistent with infection being caused by transfusion. Future studies should include contemporary US populations with linked donor specimens and populations at higher risk for HHV-8 infection.