Problem Solved? West Nile Virus and Transfusion Safety

In 2002, just three years after its appearance in the Western Hemisphere, West Nile virus caused the largest outbreak of arboviral encephalitis ever recorded in the United States.1 Epidemiologic investigations that year revealed that West Nile virus could be transmitted by blood transfusion,2 and mathematical models suggested that hundreds of transmissions had occurred.3 By July 2003, shortly before a second seasonal outbreak of similar magnitude began, collaborations among blood-collection organizations, test-kit manufacturers, and government agencies culminated in near-universal screening of U.S. blood donations for West Nile virus with the use of newly developed nucleic acid amplification tests.In this issue . . .