Halting West Nile By Transfusion

Medical Author: Frederick Hecht, M.D.
Medical Editor: Barbara K. Hecht, Ph.D.

Sept. 18, 2003 -- A report on the transmission of the West Nile virus through blood transfusion during the 2002 epidemic was released online today by The New England Journal of Medicine. The study shows that transfused red cells, platelets, and fresh-frozen plasma can transmit the virus and proposes that screening potential donors with the use of RNA-based tests for the virus may reduce or even eliminate this risk.

In the study, there were 23 people who acquired the West Nile virus through transfusions. Ten of the 23 (43%) were immunocompromised because of a transplant or cancer. The immunodeficient recipients who acquired West Nile tended to have unusually long incubation periods before they became ill. Eight of the 23 (35%) people who acquired West Nile virus by transfusion were 70 or over.

Sixteen donors with evidence of viremia (virus in the blood) at the time of donation were discovered to be linked to the 23 infected recipients. Fever, new rash, and painful eyes were associated with being a donor with West Nile viremia. All 16 of these infected donors had been negative for West Nile virus using an antibody test.