The nation’s blood supply is about to become safer. Next week blood banks will begin phasing in new genetic tests designed to wipe out viral infections that occasionally slip into transfusions.
The vast majority of transfusions already are infection-free, but the new gene testing, which should encompass all blood transfusions by September, promises to make blood even safer.
The “nucleic-acid testing” can detect tiny amounts of a virus, such as liver-destroying hepatitis C or the virus that causes AIDS, before the blood donor’s body has recognized the infection. Some of the tests can detect as few as 10 copies of a viral gene.
Viral genes spread through blood faster than the immune system begins forming antibodies to fight them, a reaction that may not occur until 20 to 80 days after infection.
Today’s blood testing depends largely on tests that detect antibodies in an infected donor. So newly infected donors sometimes slip through. Nucleic-acid testing promises to close that gap.
It probably will eliminate the few cases of HIV annually caused by donated blood, said Dr. Celso Bianco of the New York Blood Center.
