Transplants Seem Source of West Nile Virus Cases

By LAWRENCE K. ALTMAN

hree of the four recipients of organs from a single donor who had West Nile virus also developed West Nile encephalitis, strengthening the possibility that the virus can be transmitted through organ transplants or blood, federal health officials said last night.

Test findings from the fourth recipient, a 71-year-old woman in Florida, are not ready, the officials said in a news conference. The woman is recovering at home from a fever and mild illness that she developed after the transplant.

Tests performed over the weekend and yesterday provide "clear evidence that the organ transplant appears to be the source" of the West Nile encephalitis in the three recipients, said Dr. James M. Hughes, a top official of the Centers for Disease Control and Prevention in Atlanta.

But the new tests do not necessarily prove that the three patients acquired West Nile encephalitis from the organ transplants. Because the three recipients lived in Georgia and Florida, where infected mosquitoes have transmitted the virus to humans and birds, a remote possibility exists that all three acquired the West Nile virus through insect bites.

It is also unknown how the organ donor, a woman who died of complications from an automobile crash in Georgia, acquired the West Nile virus. She was not known to be ill before the crash, Dr. Hughes said.

The possibilities are that she acquired the virus either from a mosquito bite or from the many blood transfusions she received after the accident, Dr. Hughes said.

Detection last week of West Nile virus in one of the transplant recipients, a 63-year-old resident of Miami-Dade County, Fla., set off an intensive epidemiologic and laboratory investigation involving several dozen health officials in Florida, Georgia and the federal government.

Health officials said they were being aggressive in their investigation because of concern that the virus, which was first detected in this hemisphere in New York City in 1999, could be transmitted through a new route — organ transplants or blood. Because transplanted organs also contain some of the donor's blood, health officials said it may be impossible to determine whether the virus was present in only the organ or only the blood, or both.

Federal health officials are preparing to notify organ procurement agencies of the new developments and to maintain awareness of the possibility of West Nile virus transmission. But they said they were not prepared to recommend any new procedures at this time.

Dr. Jesse Goodman, an official of the Food and Drug Administration, the federal agency that regulates tests performed in blood banks and organ transplant centers, said that the government would not stop transfusions because of the theoretical possibility of transmission of West Nile virus.

Doing so, Dr. Goodman said, "would create a humongous shortage of blood in this country," and could hurt more people than it would help. The investigation is focusing on the blood that the organ donor received and other patients who received blood from the blood donors.

The organ donor was critically injured in an automobile accident and received blood and blood products donated by more than 60 people, Dr. Hughes said. Epidemiologists are trying to detect West Nile virus in the small portion of blood that is routinely kept after each blood transfusion.

Blood from the more than 60 donors has been given to about a dozen patients, Dr. Hughes said.

As a precaution, health officials said they have ordered a hold on any blood from the donors that has not been given to recipients.

In addition, epidemiologists are seeking to interview the blood donors and recipients of their blood. Health officials would also like to test them for the West Nile virus.

Detection of West Nile virus in anyone who donated blood to the organ donor would provide epidemiologic evidence that the virus was transmitted to the organ donor from a transfusion.

If no West Nile virus is found in tests of every blood donor and recipient, then scientists might presume that the organ donor was infected from a mosquito bite.

But if one or more blood donors are not tested, the source of the organ donor's West Nile virus might remain a puzzle.

Dr. Hughes said he expected that it would take two weeks or so to complete all the tests and interviews and to analyze the pertinent data.

Publicity and alerts to health departments over the weekend have not turned up any new suspect or confirmed cases of West Nile virus from organ transplants or blood transfusions, Dr. Hughes said.

Meanwhile, health officials moved to reassure the public about the relative safety of the blood supply. But they repeated their concern about the lack of a rapid test to screen donated blood for the West Nile virus.

It will take months at least to conduct the research to develop a reliable screening test, they said.

Because the government has been concerned about the theoretical risk of transmitting West Nile virus through blood transfusions, about two weeks ago health officials reminded blood banks to adhere to their usual standards to reject would-be donors who had a fever or an infection.

Dr. Goodman said he was not aware that blood centers had conducted research to randomly test donated blood for the West Nile virus. A concern is that most people infected with West Nile virus have no symptoms but could have the virus in their blood when they donate. But unlike H.I.V. and hepatitis, West Nile virus is an acute infectious disease and chronic carriers have not been detected, Dr. Goodman said.