HIV-2 Blood Screening Not Urged by FDA

America’s blood supply will not be screened for an AIDS-like virus known as HIV-2 because a study of blood tests found no trace of it, the Centers for Disease Control reported Friday.

The Food and Drug Administration decided not to recommend testing of the blood supply for HIV-2 after the CDC study found no instances of HIV-2 infection in blood donated over a two-year period.

“There is no doubt in my mind that the blood supply will have to be screened for HIV-2 some day. The question is when,” said Dr. Lyle Petersen, an epidemiologist with the CDC who participated in the study.

AIDS, or acquired immune deficiency syndrome, is caused by a virus called human immunodeficiency virus, or HIV-1. Although much less prevalent in the United States, HIV-2 causes an almost identical disease.

While HIV-2 infection is widespread in western parts of Africa, only 18 people in the United States have been found to be infected with the virus and only one of those attempted to give blood.

In that instance, the standard AIDS test for HIV-1 detected the HIV-2 infection. “In 60% to 90% (of tests of HIV-2-contaminated blood), the standard HIV-1 test will cross-react with the HIV-2 virus,” Petersen said.

When the exhaustive test of the U.S. blood supply was made, Petersen said, no blood was found that was positive for HIV-2.

To test for HIV-2 in the blood supply would cost about $60 million a year, the epidemiologist said.

Ultimately, a test will probably be developed that can reliably detect both HIV-1 and HIV-2, Petersen said.