Questions and Answers
about Blood Transfusions
This fact sheet is adapted from information
from the U.S. Centers for Disease Control and Prevention (CDC).
Is West Nile virus (WNV) transmitted by
blood transfusion or organ donation?
A recent investigation has identified
transplanted organs as the source of WNV infection in four recipients of organs
from a single donor. How the organ donor became infected is unknown. The organ
donor might have become infected from a mosquito bite or possibly acquired the
infection through transfusion; an investigation of the numerous transfusions
received by the organ donor is ongoing. Since the report of these cases, CDC
has been informed of other patients who developed WNV infection within several
weeks of receiving blood products or organs. Investigations are ongoing to
determine whether WNV was transmitted by transfusion or transplantation in any
of these cases.
What is being done about the possibility of
transfusion-related WNV transmission?
CDC, FDA, blood collection agencies, and state
and local health departments are investigating possible cases of WNV
transmission through blood transfusion and organ transplantation. For cases
currently under investigation, any remaining blood products from donors whose
blood was transfused to patients with confirmed or suspected WNV infection have
been withdrawn and efforts are underway to contact these donors as well as
other recipients of blood products from these donors for follow up.
As part of the investigation, CDC has asked
that physicians notify public health authorities of any patients who develop
symptoms of WNV infection within 4 weeks of receiving a blood transfusion or
organ transplantation. In addition, patients with WNV infection whose symptoms
begin in the weeks preceding blood or organ donation should also be reported.
Prompt reporting of these persons will help facilitate withdrawal of
potentially infected blood components.
Should people avoid donating blood or
getting blood transfusions or organ transplants?
Blood is lifesaving and is currently in short
supply. Donating blood is safe, and we encourage blood donation now and in the
future. Approximately 4.5 million persons receive blood or blood products
annually. Although persons needing blood transfusions or organ transplants
should be aware of the risk for WNV infection, the benefits of receiving needed
transfusions or transplants outweigh the potential risk for WNV
How can blood banks avoid collecting blood
from donors who may have West Nile virus?
On August 17, FDA 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. 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 of fever and
headache. Blood banks need to be vigilant to defer all of those who may have
minor illnesses, especially in areas where West Nile virus is most
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 clear the virus very quickly. Blood centers
will take precautions (see preceding question and answer) to be sure that
donors who have been diagnosed with West Nile virus have fully recovered before
If I recently had a transfusion or
transplant, should I be concerned about getting West Nile virus?
You should be aware of the potential risk for
WNV infection and the need to monitor your health. If you have symptoms of West
Nile virus or other concerns you should contact your physician. However, it is
important to remember that a large number of WNV infections due to mosquito
bites have occurred among persons in the United States this year. By chance
alone, some of these persons will have received blood transfusions and/or organ
transplantations. Recent receipt of a blood transfusion or organ
transplantation by a person with WNV infection does not necessarily implicate
the transfusion/transplantation as the source of infection.