Risk Remote for West Nile Infection Via Transplants, Transfusions

The Centers for Disease Control and Prevention in Atlanta recently confirmed West Nile virus infection, a virus that sometimes causes a form of encephalitis, in three of four individuals who recieved organs from a single, female donor who died in a Georgia car crash. The CDC reports that an infected donor organ likely resulted in the Aug. 29 death of one recipient.

Although CDC officials are still determining the organ donor's cause of infection, they believe the cases are the first in which humans contracted the disease through something other than a mosquito bite. Approximately 60 people, who officials are locating for more testing, donated blood which was transfused in an attempt to save the woman's life. Unused blood and blood products processed from the donations were immediately recalled until further testing can be performed, but about a dozen people had already received transfusions.

Currently, the West Nile virus testing process takes about 15 days, and is based on patients' immune response, or production of antibodies, to fight the virus. Those with weakened immune systems, such as organ transplant recipients who received drugs to combat the rejection of a transplanted organ, may be especially susceptible to the virus. At this time, the CDC is working on a quicker blood test for individuals already showing signs of West Nile infection. Currently, there are no plans to screen all blood, organ or tissue donors for the virus.

Locally, representatives from both Gulf Coast Regional Blood Center and LifeGift Organ Donation Center are working to ensure the safety of patients receiving services and support from these organizations. Presently, the blood center supplies blood and blood components to more than 200 hospitals and health care facilities in a 24-county southeast Texas region; LifeGift serves 109 Texas counties, including Harris.

A thorough screening process is conducted by each organization. The Blood Center, adhering to federally established and mandated Food and Drug Administration guidelines, conducts approximately a dozen tests on every unit of blood collected. A normal temperature is required of each donor, and a series of general health questions are asked.

Although there is no current West Nile blood donor test, there is only a miniscule risk for virus transmission.

Susan Rossmann, M.D., the blood center's medical director, said the time the virus stays in the blood varies from person to person, but averages about six days. She emphasized that many people who have been infected never develop symptoms. For those who develop the flu-like symptoms, the incubation period averages three to 14 days after infection.

"I am concerned that people who need blood transfusions, and their families, may be unnecessarily worried about West Nile virus. The West Nile risk is tiny compared to the tremendous benefits of patient transfusion," Rossmann said, "and blood donation does not put one at risk for contracting the virus. Despite the concern, the number of people who actually have West Nile appears to be small."

LifeGift's medical and social history questionnaire for potential organ and tissue donors includes topics ranging from drug and alcohol use, to travel and health history.

Sean Conley, LifeGift's tissue recovery and communications manager, said the organization also accounts for how much blood potential donors have received. He said organ and tissue procurement personnel do an exhaustive investigation into the potential donor's cause of death, and assessment questions are asked of family members and others close to the deceased individual, including primary care physicians, caregivers, and emergency medical technicians and doctors who treated the patient at the time of death.

"The questions cover disease symptoms caused by high-risk behaviors," Conley said, "but also point to other possible diseases such as West Nile."

However, organ and tissue procurement organizations are also challenged by the fact that there is no available West Nile blood test.

Similar to the Blood Center, Conley said LifeGift also follows strict FDA donation guidelines. Potential donors are screened for numerous diseases such as HIV, AIDS, hepatitis and cancer. Tissue such as bone, skin, corneas, heart valves and veins, are scrutinized carefully before transplantation.

Organ and tissue procurement organizations must keep written or electronic records that document donor testing for 10 years, and the FDA may inspect the facilities at any time to ensure compliance.

Charles Van Buren, M.D., LifeGift's executive vice president and chief medical officer, said that immunosuppressive drugs pose the highest illness risk the first four weeks following transplant. However, not all transplant patients are the same, and must be handled on a case-by-case basis.

"As time goes by, I'm sure we'll find transplant patients who contracted the West Nile virus, and their bodies were able to handle the illness similar to the way a normal, healthy person not taking immunosuppressants would," Van Buren said.

WEST NILE FACT AND FICTION

The following Q & A fact sheet was prepared by the Centers for Disease Control and Prevention, and distributed through their Health Alert Network.

Is West Nile virus transmitted by blood transfusion?

To date, there are no documented instances where West Nile virus was transmitted through transfusion. However, the virus may be transiently present in the blood of those infected, so it is possible that this could occur.

What is being done about this possibility?

On Aug. 17, the Food and Drug Administration issued an alert to blood banks and organizations to be vigilant in excluding individuals who may have early symptoms of West Nile virus from donating blood. In addition, the FDA and the Centers for Disease Control and Prevention have asked that blood banks and others report cases where a blood recipient develops West Nile virus for investigation of whether transfusion could have been involved. An investigation is now being conducted by the CDC to determine whether blood transfusion or donor organs were the West Nile sources for the current transplant recipient cases.

What else can be done to protect people against this possible threat?

As a precaution in this case, blood banks are recalling any remaining units of blood products from all donors whose blood was administered to the organ donor. There is currently no validated blood test to screen donated blood. If it is shown that people without symptoms can transmit West Nile virus through donating blood, public health partners will work with others to help facilitate availability of such a test.

Should people avoid donating blood or getting blood transfusions?

Blood is a lifesaving necessity and is currently in short supply. Donating blood is safe and donations are always encouraged. For patients who need a blood transfusion, the benefits far outweigh any risks.

How can blood banks avoid collecting blood from donors who may have West Nile virus?

Most people who have West Nile virus do not show symptoms making it difficult to defer them from donation. However, some individuals develop minor symptoms, such as fever and headache. Blood banks will be vigilant and defer all of those who may have minor illnesses, especially in areas where West Nile virus is most active.

If a person has had West Nile virus, can they still donate blood?

With West Nile virus infection, the viremia usually is transient and people recover quickly. Blood centers will take precautions to be sure that donors who have been diagnosed with West Nile virus have fully recovered before donating.

If I recently had a transfusion, should I be concerned about getting West Nile virus?

Although there have been no cases where transmission by blood transfusion has been documented, if infection were to set in, it could be expected in three to14 days. It is unknown what incubation period would be expected if transmission were transmitted by transfusion. Those with West Nile virus symptoms or other concerns should contact their physician.

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©2006 Texas Medical Center

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