UNOS News Release

Status of Investigation Into West Nile Infection in Organ Transplant Recipients

Federal and state public health officials are vigorously investigating a recent case of possible development of West Nile viral infection among transplant recipients from a single organ donor. The Health Resources and Services Administration (HRSA) and the United Network for Organ Sharing (UNOS) want to ensure that transplant professionals, transplant candidates and recipients and the public know the status of this investigation. In addition, we want to provide resource information about West Nile virus to help transplant professionals be aware of its etiology and treatment options. HRSA has additionally issued an Advisory Alert, which is also available on this site.

The investigation stems from an incident where organs recovered from a single donor on August 1, 2002 were transplanted into four recipients. All four recipients demonstrated clinical symptoms and/or laboratory test results consistent with a West Nile infection, and now all have been confirmed to have contracted the West Nile virus. One recipient died, one has improved and returned home, and the other two remain hospitalized. The onset of illness for these recipients occurred as late as 17 to18 days post-transplant, which is longer than the typically observed incubation period of 3 to 14 days for the virus.

It is not known how these transplant recipients were infected. It is possible, but not definite, that the transplanted organs transmitted the virus. If so, the donor may have acquired West Nile through a mosquito bite or from blood transfusions that occurred prior to death. Laboratory testing is underway to determine whether the organ donor, and/or the blood donors whose blood products were used, had the virus present.

West Nile infection in organ transplant or blood transfusion recipients has not been previously reported, and the risk of acquiring the disease from these sources is not known; however, the risk is thought to be low. Clinicians caring for early-term post-transplant recipients with febrile illnesses associated with unexplained encephalitis or meningitis should consider West Nile infection as a possible cause of illness. The resources below provide additional details that may be helpful in assessing this possibility.

The OPTN/UNOS Organ Procurement Organization Committee discussed this issue at its meeting Sept. 9. Given the lack of any current FDA-approved test for the West Nile Virus, the committee agreed that for the immediate future, the best course of action is for organ procurement organizations to continue their thorough screening process for all types of infection including the extensive medical and social history, physical examination and medical testing currently in place.

We hope the public reporting of this case, while vital to protecting the public health, does not deter organ or blood donation. These donations save and enhance the lives of countless men, women and children every year. It is important to study this case to determine and minimize the risk of West Nile infection, but the far greater risk is that lives may be lost if public confidence in donation is shaken.

The following Internet-based resources provide additional information about West Nile and will continue to be updated as more becomes known in this ongoing investigation. Thank you for your attention and cooperation.

The most recent CDC Press Release and the updated status of its investigation can be found on its website: http://www.cdc.gov/od/oc/media/wnupdate.htm

The September 13 edition of the Morbidity and Mortality Weekly Report (available by preview) addresses investigation of West Nile among blood donors: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5136a5.htm

A full description of the clinical features and diagnostic test options for West Nile virus infection also can be found on the CDC web site: http://www.cdc.gov/ncidod/dvbid/westnile/resources/fact_sheet_clinician.htm

A Food and Drug Administration alert regarding West Nile virus and blood safety can be found on its web site: http://www.fda.gov/cber/safety/westnile.htm

The American Association of Blood Banks has issued a fact sheet regarding the investigation and the possible risk of transmission through blood transfusion: http://www.aabb.org/Pressroom/In_the_News/wnile0905.htm