West Nile Virus (WNV)
Individual at risk
Donor / Recipient
Guidance at RECRUITMENT for adult volunteer donor and maternal donor (cord blood donation)
Accept if fully recovered Defer if prior infection with residual organ/neurologic deficits
Guidance at CT/WORK-UP
Evaluate for deferral if:
Less than 120 days from diagnosis or onset of symptoms, whichever is later
History of infection with residual organ/neurologic deficits
Justification for guidance
FDA Guidance for Industry Eligibility Determination for Donors of Human Cells, Tissues, and Cellular and Tissue-Based Products (HCT/Ps), August 2008
West Nile Transmission via Organ Transplantation and Blood Transfusion---Louisiana, 2008: CDC MMWR 58(45):1263-67.
WNV has been transmitted via blood transfusions and, theoretically, can be transmitted via stem cell donation. It is an infection caused by a flavivirus commonly found in parts of Africa, western Asia, and the Middle East. It is also present in the United States since 1999. It can reside in animal hosts including birds, mosquitoes, horses, and some other mammals. In 2012 in the US, there were 5,387 cases with 243 deaths. WNV infection can be as short as a few days to as long as several weeks. About 80% of infections are asymptomatic. Because symptoms of WNV infection can be non-specific, FDA donor eligibility guidelines state that the following clinical evidence should be considered when evaluating a potential donor: fever, headache, body aches, or eye pain; occasionally, infections are manifest as truncal rashes or lymphadenopathy. It is estimated that 1 in 50 persons infected develop more severe disease resulting in encephalitis, meningitis, meningoencephalitis, and acute flaccid paralysis. Signs and symptoms of severe infection include headache, high fever, meningismus, altered mental status, coma, tremors, seizures, and muscle weakness.
Although there is limited data one the natural history of the disease, the FDA recommends a 120 day assessment period because of reports of prolonged viremia.