FDA spokeswoman Karen Riley defended the government agency's decision, saying that epidemiological data from the U.S. Centers for Disease Control and Prevention indicates "men who have sex with other men have the highest risk of transfusion-transmitted diseases like HIV and hepatitis."

"We acknowledge that not everyone in a high risk group is indeed at risk and, as science advances, we periodically review our policy," she said. "We continue to be open to reviewing new information and any new scientific studies that would support a change in policy."

In 1983 when AIDS was spreading mainly among white gay men, the FDA decided to put a ban on all men who had or had had sex with other men since 1977 as they were considered to be at higher risk of contracting and transmitting HIV and hepatitis which could prove dangerous to the health of the blood recipients.

Testing for HIV and other infectious diseases, as the Red Cross and the America's Blood Centers experts told the FDA, has improved enormously since 1983. The strict testing of today will screen out their blood if it is infected with HIV.

The only exception is men newly infected within three weeks prior to donating. Admittedly this "window period" during which someone can be infected with HIV and not test positive even with the best of tests is a risk. But the right response is to exclude anyone who has engaged in any risky sexual or drug behavior for a month prior to donating blood.

"If you look at the risk of contracting HIV or hepatitis C, for example, from a blood transfusion, the risk is one in 2 million or less," an infectious disease specialist with the Mississippi Valley Regional Blood Center in Davenport Iowa said. "In fact, the rates are so low, we can only do statistical models to determine the odds."

The policy adopted by FDA has been criticized on the grounds that it not only prevents potential healthy donors to contribute to the blood banks, despite the desperate need for it, but also discriminates against the gay community.