Update: Investigations of West Nile virus infections in recipients of organ transplantation and blood transfusion.

An investigation involving CDC, the Food and Drug Administration (FDA), the Health Resources and Services Administration (HRSA), the Georgia Division of Public Health, and the Florida Department of Health identified West Nile virus (WNV)-associated illnesses in four recipients of organs from the same donor. Although the transplanted organs were the source of infection for the four organ recipients, the source of the organ donor's infection remains unknown; an investigation of the numerous transfusions received by the organ donor is ongoing.