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West Nile and Transplants May Take Weeks
By
LAWRENCE K. ALTMAN
 t
will take at least two weeks to determine whether the West Nile
virus was transmitted through organ transplants or blood
transfusions to a cluster of four transplant recipients in whom
encephalitis has been diagnosed or suspected, federal health
officials said yesterday.
But the unproved yet real possibility that transfusions had
transmitted the disease had the officials yesterday acknowledging
this concern: there is no rapid test to screen donated blood for the
West Nile virus. It will take at least months to conduct the
research to develop a reliable test, they said.
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Until there is a test, they said, blood donors and recipients
will have to consider the theoretical risk that receiving a
transfusion or transplant could expose them unwittingly to West
Nile.
The officials insisted, however, that the nation's blood supply
was safe, and that the risk of acquiring the virus was surely the
least concern for anyone needing blood or a new organ. The risk of
transmitting the virus through blood transfusions is calculated to
be low — in the range of 1 to 2 cases per 10,000 transfusions,
officials from the Centers for Disease Control and Prevention in
Atlanta and the Food and Drug Administration in Washington said.
About 13 million units of blood are collected each year in the
United States.
Because blood is involved in the natural transmission of West
Nile — through mosquito bites — doctors have theorized that West
Nile could be transmitted through transfusions and organ
transplants. Two weeks ago, health officials said they reminded the
nation's blood banks to enforce a standard procedure — rejecting
donations from patients with fever and flulike symptoms, which could
be symptoms of mild West Nile fever.
But the chief executive of the New York Blood Center, Dr. Robert
L. Jones, said that if transfusion transmission of West Nile virus
was confirmed, blood bank officials might have to ask about a
history of mosquito bites. That step could vastly reduce, if not
deplete, the number of donors, and aggravate an already serious
shortage of blood in the country. Dr. Jones and the officials urged
the public to donate blood.
The concern arose in recent days when health officials learned
that a transplant recipient had developed West Nile encephalitis.
That case sparked an investigation that has found the cluster in
Georgia and Florida from a single organ donor, raising suspicion
that the virus could be transmitted through organ transplants or
blood transfusions or both.
This year, the nation is experiencing its worst outbreak of West
Nile fever since the virus was first detected in this hemisphere, in
1999 in New York City. Over the weekend, the total number of cases
has risen to 638, including 31 deaths.
Preliminary tests of a patient who died with encephalitis after
receiving a kidney from the donor show evidence of infection with a
mosquito-borne virus. Further tests are needed to prove it is West
Nile virus.
On Friday night, the C.D.C. director, Dr. Julie L. Gerberding,
said her agency was taking the situation seriously because of
significant concern about the possibility of transmission of virus
through blood. But as of yesterday it was premature to conclude that
blood transfusions were the source of the donor's infection.
In recent days, the centers asked doctors and hospitals to report
possible cases of West Nile fever through blood and organ
transplants to their local health departments. A concern is that
because most people who are infected with the virus experience no
symptoms, they could donate blood without knowing they have it.
If so, the period of transmissibility is likely be short, "a few
days to a couple of weeks at the most," Dr. Jesse Goodman, an F.D.A.
official said. But, he added, "in an unfolding situation, we don't
want to be speculative or pretend that we have exact or precise
information."
Dr. Goodman said he would not expect people who have recovered
from an infection to have West Nile virus in their blood for long
because by the time symptoms develop, the virus is difficult to
detect. In such cases, evidence of West Nile infection is based on
detecting the specific antibodies that a patient's immune system
develops in response to the infection. "It is very important to
recognize that unlike H.I.V. or hepatitis, West Nile virus is an
acute infectious disease and we are unaware of any kind of chronic
carrier state," Dr. Goodman said.
Asked if health officials could assure Americans that the
nation's blood supply is safe from West Nile virus, Dr. James M.
Hughes, a top C.D.C. official, said: "We can't give guarantees. We
think we have a very safe blood supply."
He also said: "If I were a person with severe chronic disease and
I needed an organ transplant, concern about this would be right at
the bottom of my list of things that I was worried about. Similarly,
if I needed a transfusion this would be at the bottom of the list of
my concerns. If I lived in an area where West Nile was circulating,
which is much of the country at the moment, my greatest concern
about West Nile would be to take precautions to minimize my risk of
being bitten by mosquitoes."
Dr. Jones of the New York Blood Center said the threat of
transfusion-borne West Nile virus had to be taken seriously. The New
York area relies on blood imported from Europe and elsewhere in the
United States, including the South, where West Nile is a particular
problem this year.
Federal officials have urged blood centers to exclude donors who
lived in England and other foreign areas where mad cow disease has
occurred. Such exclusions have depleted donations in New York City
by 25 percent this summer, Dr. Jones said.
He added that every medical procedure carried risks. "If we were
to guard against every risk, theoretical or otherwise, we would have
no blood supply, and patients who need blood would suffer the
consequences," Dr. Jones said.
Available tests for West Nile virus are intended to detect
infections in symptomatic patients and have not been rigorously
assessed for their ability to detect the virus in people without
symptoms, which would become important if the organ donor became
infected through a blood transfusion, Dr. Goodman said.
National Briefing | Science And Health: 25 Contract West Nile Virus
This Year (October 5, 2001)
METRO NEWS BRIEFS: NEW YORK; West Nile Virus Caused Encephalitis
(October 22, 1999)
Exotic Virus Is Identified In 3 Deaths (September 26, 1999)
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Hot Weather Cited In Spread of a Virus (August 9, 2002)
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