More evidence organ donations may spread West Nile

ATLANTA, Georgia (CNN) -- Three of four people who received organ transplants from a single donor last month have West Nile virus, and the donor also had the illness, evidence the virus could have been transmitted through the donated organs, the Centers for Disease Control and Prevention announced Tuesday.

One of the transplant patients has died. The others are recovering.

The CDC and other health authorities stressed their investigation of the cases is continuing, and they said findings so far have not proven the organ donor was the source of the virus in the organ recipients.

The key of the investigation may be the source of the virus for the organ donor, a Georgia woman who was fatally injured in a car accident July 30. Her kidneys, heart, and liver were donated and implanted in the four patients after her death.

The woman received blood transfusions from more than 60 people before she died. Health authorities are trying to figure out whether the woman was infected through the donated blood or by a mosquito bite, which so far is the only known cause of human contamination.

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If the human-to-human transmission is confirmed, it would be the first known case of its kind.

"That's the focus of the active, ongoing investigation," said Dr. James Hughes, director of the CDC's National Center for Infectious Diseases.

Patients lived in active West Nile areas

Of the four transplant patients, three of the four had encephalitis brought on by West Nile. One died and the other two are recovering. Samples from the fourth patient, whose only symptom is a fever, are still being tested for the virus.

The CDC advises that most people never know they have been infected by the virus, one of five develop mild flu-like symptoms, while less than one percent develop severe neurological disease.

Two of the organ recipients live in Florida; the other two, including the one who died, are from Georgia.

"In this cluster of three confirmed cases of West Nile virus infection, with the possibility that there'll be a fourth, there's clear evidence that organ transplantation appears to be the source," Hughes said.

"Having said that, these patients all live in areas where mosquito-borne transmission of West Nile virus is occurring and is continuing to occur," he said. "This is complicated. It's important that we not jump to conclusions."

Authorities are unaware of any other "clusters" of West Nile virus infection involving organ donors and recipients, he said.

The organ donor was not the only one to receive blood from those 60-plus people. Health authorities said Tuesday that "roughly a dozen" others got blood from those blood donors.

If the Georgia woman got West Nile virus from the blood transfusions after the accident, health authorities said, it will be crucial to track down those recipients as well.

No test to screen blood for West Nile

"In terms of how did the donor acquire this West Nile virus infection, the two possibilities are a mosquito bite before the time that the person was injured in the automobile accident, or received a blood product immediately after being injured," Hughes said. "I think we have to aggressively pursue the possibility that a blood product is responsible for this."

While the idea of West Nile virus being transmitted through donated blood is frightening, Dr. Jesse Goodman of the Food and Drug Administration pointed out the risks for such a scenario -- if it is proven to occur -- are still small.

"That doesn't mean it's acceptable, but we need to keep the risk in perspective," Goodman said.

Hughes said no one should fear seeking a blood transfusion if they need it, again stressing there is no evidence the nation's blood supply is or can be contaminated with West Nile.

Blood from the 60-plus donors that has not yet been administered is now being recalled, Hughes said.

There are currently no FDA-approved tests that could be used to screen blood products or organs for West Nile. But Hughes and Goodman said the risk is low enough that there is no need for a moratorium on blood transfusions.

The West Nile epidemic in the United States exploded this summer, three years after it was first detected in birds, horses, and eventually humans in the northeastern United States.