Because NAT looks directly for the genetic material of viruses, either DNA or RNA, the test can detect an infectious agent's presence much earlier than current screening tests. Most available tests detect the antibodies formed as part of the immune response to a virus, often 20 days to 11.5 weeks after infection. NAT may decrease the time after initial donor exposure to when detection is possible. For HIV, this time is usually six to 10 days after exposure, which NAT should reduce by 30 to 50 percent and for HCV, about 41 days, which NAT should shorten by 50 to 98 percent.
While the Red Cross' testing of NAT focuses on HIV and HCV, the test can be tailored for future use to screen for other blood-borne pathogens and for newly emerging viruses, bacteria or fungi for which genetic material has been identified.
The Red Cross estimates that rates of NAT-reactive donations among those volunteer donors that test negative by currently performed screening tests for HIV and HCV are one per million donations for HIV and one per 100,000 for HCV.
"By adapting technologies like NAT, the American Red Cross is continuing in its mission to develop ways to improve the safety of the U.S. blood supply and reduce the risk of disease transmission through blood products," says Richard Davey, M.D., chief medical officer of the Red Cross.
Approximately 4 million people annually receive blood or blood products as part
of their medical or surgical care in the United States. Blood centers have
implemented several overlapping strategies to safeguard the nation's blood
supply-- including screening of the donor and viral testing of donations-- to
reduce the transmission of virally infected blood. However, a small risk of
transmission of viral infection through blood transfusion remains because of
donations during the so-called "window period" in which antibodies have not yet
formed despite the donor's exposure to the virus.
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Contact: Ernie Knewitz
ernie.knewitz@noonanrusso.com
212-696-4455 x204
Noonan/Russo Communications
8-Apr-1999