Organ Transplants:

Current Organ Procurement and Transplantation Network (OPTN) policy requires that living donors be evaluated for risk of transmitting WNV to recipients. Since the majority of WNV infections are asymptomatic, clinical screening will not effectively identify infected donors. Laboratory screening is thus recommended during periods of human WNV activity where the donor lives, works, or travels. Establishing a relationship with local blood banks allow transplant centers to conduct testing only during periods of human WNV activity and reduce false positive results and as well as testing costs.

Seasonal testing during potential periods of WNV activity (May to November) is an alternative strategy but would potentially have a higher false positive rate and be less cost effective. While transmission of WNV from NAT negative (no viremia) but IgM positive donors has occurred, the performance of IgM assays as screening tests has not been validated and cannot be routinely recommended.

No proven cases of donor-derived WNV infection from living donors have been reported. However, 9 deceased donors have transmitted WNV to 18 of 26 (69%) recipients. In at least two cases, the source of the WNV was blood transfusions received by the donor. Disease in recipients typically developed soon after transplantation, and outcomes have been poor with encephalitis or other severe neurological disease commonly occurring. In some cases, transmission has occurred from NAT negative IgM positive donors, suggesting that WNV may be present in organs and transmissible after the virus has cleared from the plasma.

However, screening organs for WNV poses particular problems, so universal screening has not been recommended.  There are nucleic acid tests  (NATs) available for use in screening organ and tissue donors, but a number of factors makes this screening impractical in most cases:

Because of these problems, the Health Resources and Services Administration (HRSA) of the Organ Procurement and Transplantation Network has recommended the following:

For deceased donors, HRSA recommends transplanting an infected organ only if the potential recipient has an emergent, life-threatening illness and no other organs or life-saving measures are available.

Instant feedback:

WNV infected organs may be used for transplant under some conditions.


U.S. Department of Health & Human Services. Organ Procurement and Transplantation Network. Identifying Risk Factors for West Nile Virus (WNV) During Evaluation of Potential Living Donors. Retrieved 11/3/17.