GAITHERSBURG, Md. - Government scientists narrowly rejected a proposal to ease the ban on gay male blood donors Thursday, citing concern that there wasn't enough evidence about how the move might affect the AIDS risk to the nation's blood supply.
All men who seek to donate blood are asked if they have had sex, even once, with another man since 1977. Those who admit they have are permanently banned from donating blood.
The Food and Drug Administration asked its scientific advisers Thursday whether it should change the blood-donation rule to ban only men who had sex with another man within the last five years.
But the advisers voted 7-6 that there was not enough evidence that it was safe to make that change. The FDA is not bound by its advisers' decisions but typically follows them.
Changing the policy would have resulted in about 62,300 gay men - or men who had experimented with homosexual activity only once - seeking to donate blood, estimated FDA medical officer Dr. Andrew Dayton. From them, 1.7 HIV-infected units of blood might sneak into the blood supply, he said.
The issue has split the blood industry, with half of the nation's blood banks supporting easing the policy even more - to one year instead of five - while the American Red Cross opposes any change.
All donated blood undergoes strict testing for the AIDS virus and other blood-borne diseases - that would not have changed. But testing isn't perfect. Of the nation's 12 million units of donated blood, about 10 HIV-infected units slip through each year, causing about two to three HIV infections a year, said Dr. Michael Busch of the University of California-San Francisco.
So as an extra precaution, the FDA also requires blood banks to question potential donors about their risks for HIV and other diseases and refuse the blood of high-risk people. The hope is people will not lie, although studies show many do.
The ban on gay male donors was adopted in 1985 because the deadly AIDS virus first appeared here as an epidemic in the gay community. Later, other high-risk people were barred from donating, such as intravenous drug users and prostitutes.
But now - with the nation bracing for blood shortages and new genetic testing that promises to eliminate the rare cases of HIV still caused by donated blood - many blood banks are asking why they have to turn away thousands of potentially healthy men.
''I don't think there's enough information to make a decision at this point in time,'' said John Boyle, a Maryland blood safety consultant for the FDA.
But even panelists who voted against the change did encourage the FDA to continue to study how to change what several called a discriminatory policy that mandates no gay men can give blood even though doctors are only worried about a subset of that populations.
About 8 percent of gay men have HIV, the government estimates.
''We cannot change our procedures in a way that would result in increased numbers of infectious donation in our blood supply,'' said Dr. Rebecca Haley, the Red Cross's chief medical officer.
The FDA considered easing the ban partly because the nation is facing an increasingly tight blood supply.
Only 8 million Americans donate blood, just 5 percent of currently eligible donors. Blood donations are decreasing about 1 percent a year, while demand for blood is increasing by 1 percent a year.
Already, some cities routinely experience blood shortages during holidays and the summer, when regular donors go on vacation, and blood banks are bracing for more serious shortages if donations continue to decline.
Until recently, all donated blood was tested for immune system cells that fight HIV. But those antibodies may not appear until 80 days after an infection, so newly infected donors have sometimes slipped through. Last year, however, blood banks began using a new genetic test that they believe can largely eliminate that risk. Nucleic acid testing, or NAT, can detect tiny amounts of a virus before the donor's body has even recognized the infection, 11 days after a person is infected.
That means the test could easily catch HIV infection in a man who had sex with an HIV-infected man a year ago, much less five, said some blood banks that urged the FDA to go with a one-year policy instead.
Last spring, a human rights commission in South Africa ruled that gay men have a constitutional right to donate blood.