The United States Food and Drug Administration (FDA) has lifted a 30-year-old ban on blood donations by gay men, but only if they have not had sexual contact with another man within the last 12 months.

An article on scientificamerican.com says the agency overturned the ban that was put in place as a way of preventing the transmission of HIV, the virus that causes AIDS.

The agency plans to continue to ban people with blood clotting disorders, such as hemophilia, primarily because of the harm that could be caused to the donors by the large needles needed to collect the blood.  Previously the FDA had banned those individuals due to an increased risk of transmitting HIV as well.

Several countries, including Australia and the United Kingdom, have similar 12-month waiting periods in place already.  Studies done on over 8 million units of donated blood were performed and the findings revealed no change in risk to the blood supply by using the 12-month deferral.  The agency said similar data for shorter periods of time were not available at this time.

In announcing the change in policy, the FDA said it has worked with several other governmental agencies, as well as considering input from outside advisory bodies.  The agency said it had carefully examined the most recent available scientific evidence to support their decision.

The agency has also implemented an safety monitoring system for the supply of blood donated, and it expects to provide critical information to better inform policy changes by the FDA in the future.

The FDA said the policies it has in place have helped to reduce the HIV transmission rates from blood transfusions from one of 2,500, to a rate now of one in every 1.47 million transfusions.

An advocacy group, Gay Men’s Health Crisis (GMHC), was critical of the 12-month delay part of the new policy, according to thetimesgazette.com.  The group CEO, Kelsey Louie, said modern measures in HIV testing have been ignored while perpetuating the thinking that all bisexual and gay men were inherently dangerous.