September 11, 2002 |
Contact:
HRSA Press Office
301-443-3376 |
HRSA ALERT: POSSIBLE WEST NILE VIRUS TRANSMISSION
THROUGH ORGAN TRANSPLANTATION
The Health Resources and Services Administration, (HRSA) Office of
Special Programs, is issuing this alert to organizations associated
with organ transplantation about a suspected case of transmission of
West Nile virus through organ transplantation. In addition, this
alert notice provides a summary of the current status of the ongoing
investigation of this case.
The investigation has focused on a cluster of cases of West Nile virus
infection through transplantation of organs from one donor. The
organ donor received multiple blood transfusions prior to death and
testing of the donor demonstrated evidence of West Nile virus infection.
All four of the persons who received organs from the single donor became
infected with the West Nile Virus; one died and two remain hospitalized
and one is recuperating at home.
Organ transplantation has not been confirmed as the route of
the recipients’ West Nile virus infection. However, the Centers
for Disease Control and Prevention (CDC) has confirmed infection in
all four recipients in this case. CDC has indicated that the donor
most likely became infected with the West Nile virus through a mosquito
bite or via blood transfusion shortly before organ donation. HRSA
recommends all organizations associated with organ transplantation keep
current on this matter and be prepared to implement precautionary procedures
that may be recommended by federal and state health authorities.
- To date, CDC and the Food and Drug Administration (FDA) have
found insufficient information to recommend changes to existing organ
or blood donor screening and testing practices. As a precaution,
the remaining blood products from blood donors whose blood was given
to the organ donor have been voluntarily withdrawn from use.
- Clinicians caring for organ transplant patients with febrile
illnesses – particularly patients with unexplained meningitis or encephalitis
in the weeks following transplant -- should consider West Nile virus
infection as a possible cause of the illness.
- West Nile infection can be detected by IgM antibody in cerebrospinal
fluid (CSF) or serum samples by MAC-ELISA. Laboratory evaluation
of the CSF in the organ recipients may not be consistent with common
findings in patients with encephalitis (such as pleocytosis and elevated
protein). According to CDC, clinicians who suspect West Nile
Virus can obtain rapid testing at State laboratories through State
and local health departments.
Status of Investigation:
The CDC, the FDA, the Georgia State Division of Public Health, and
the Florida Department of Health are continuing to investigate how the
four organ recipients became ill. All four showed symptoms of
viral infection after the transplant. The onset of their illness
occurred 17 to 18 days after transplant, which is longer than the typically
observed incubation period of 3 to 14 days for the West Nile Virus.
Each of the four organ recipients demonstrated clinical symptoms and/or
laboratory test results consistent with a West Nile infection.
It is not known how the donor was infected. It is most likely
that the donor may have acquired the West Nile virus through a mosquito
bite or through blood transfusions that she received prior to removal
of the organs. It is also not certain how the organ recipients
were infected. The organ recipients were most likely infected
through mosquito bites or through the transplanted organs. Laboratory
tests are underway to determine whether West Nile Virus was present
in the organ donor or in the blood of donors whose blood products were
used in the transfusions. West Nile Virus infection in organ transplant
or blood transfusion recipients has not been previously reported and
the risk for acquiring West Nile Virus infection from donated organs
or blood is not known. As stated above, present information is
insufficient to indicate changes to existing organ or blood donor screening
and testing practices.
Additional information from CDC and FDA about the West Nile Virus
and organ transplantation:
- Although there are no data about the stability of West Nile Virus
in refrigerated blood or blood components, flaviviruses such as West
Nile in general are known to survive over long periods in fluids with
high protein content and would be expected to have good stability
in blood.
- West Nile Virus is a lipid-enveloped virus and is expected to be
destroyed during the viral inactivation procedures used in the plasma
derivative manufacturing process. Therefore, there should be
minimal risk of transmission to recipients of manufactured plasma
products.
- Most West Nile Virus infections are mild and present no symptoms
to the infected person. In the general population, 20 percent
of those infected develop a mild illness and approximately 1 in 150
infections result in severe neurological disease. Organ transplant
recipients, however, have weakened immune systems and may be at greater
risk of severe disease if infected. The risk of infection by
West Nile Virus for organ transplant recipients has not been calculated.
- As stated earlier, the typical West Nile incubation period is thought
to range from 3 to 14 days, but the onset of illness for the four
transplant recipients began as late as 17 to 18 days after transplantation
of the organ.
- Symptoms in the four transplant patients under investigation started
as fever unresponsive to antimicrobial therapy, headache, backache
and non-specific respiratory symptoms. Three patients developed
progressive decline in mental status and required mechanical ventilation.
The patient who died succumbed from brain stem herniation. Although
not observed in recent outbreaks, myocarditis, pancreatitis and fulminant
hepatitis have been described in West Nile Virus infections.
- Treatment is primarily supportive. Ribavirin in high doses
and interferon alpha-2b were found to have some activity against West
Nile Virus in vitro, but no controlled studies have been completed
on these drugs or other medications in the management of West Nile
Virus encephalitis.
HRSA is advising all OPOs and transplant centers to be alert to the
risks of West Nile Virus and to be aware of all daily updates provided
by the CDC and FDA.
Resources for Updated Information:
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.
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
A full description of the clinical features and diagnostic test options
for West Nile virus infection can be found on the CDC web site:
http://www.cdc.gov/ncidod/dvbid/westnile/resources/fact_sheet_clinician.htm
A transcript of a Sept. 3 CDC telebriefing on the investigation is
also available on its site:
http://www.cdc.gov/od/oc/media/transcripts/t020903.htm
A FDA 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/industry_news.htm
HRSA will continue to monitor the situation with the CDC and the
FDA and provide periodic updates to the transplant community.
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