A blanket ban on blood donation by gay men is unjustified and untenable, one of the world's leading AIDS researchers says.
Mark Wainberg, head of the McGill University AIDS Centre, said the prohibition, which has been in place since 1983, needs to be refined to reflect scientific evidence.
Practically, that would mean deferring blood donations by those with multiple sex partners, whether they are homosexual or heterosexual.
That would mean allowing blood donations from gay men in a stable, monogamous relationship, Dr. Wainberg said in an article published in Wednesday's edition of the Canadian Medical Association Journal.
"The 1983 ban has hung on so long, unfortunately, because many people became infected by HIV in the early 80s through blood transfusions, and they have mounted continuing pressure on the blood agencies to maintain the ban," he wrote.
"While we can sympathize with them, this no longer makes sense in 2010, and with each passing year it makes less sense."
Ron Vézina, national director of media relations at Canadian Blood Services, said the ban has remained in place because uncertainty remains and the agency has an obligation to err on the side of safety.
"The key for us is that there isn't medical consensus on the matter," he said.
"Patient safety comes first and we won't make any policy changes that would put the blood supply at risk," Mr. Vézina said.
Just over half of the 65,000 Canadians infected with HIV-AIDS are men who have had sex with men, according to data from the Public Health Agency of Canada.
An estimated 5.4 per cent of gay men are infected with HIV-AIDS, compared to 0.08 per cent of heterosexuals - a 67-fold difference.
However, Dr. Wainberg noted, more than 94 per cent of men who have had sex with men are HIV-negative. The sweeping ban in place now means that a lot of potential donations from healthy gay men are being lost, he said.
When the ban on blood donation was first adopted, there was not yet a test to detect HIV. It was subsequently upheld because of fears that an infected unit could go undetected.
Dr. Wainberg said improvements in testing mean the chances of an infected unit slipping through are slim. He noted too that there has not been a single case of a Canadian contracting HIV from a blood transfusion in more than 15 years.
Aside from Canada, the U.S., France and Germany all maintain lifetime bans on blood donation by men who have had sex with men. But other countries, such as Australia, Japan and Sweden, impose only a one-year deferral on those who have had multiple homosexual partners. That means if a gay man has had only one sexual partner in the past year, he can give blood. (Canada has such a policy only for heterosexuals.)
The issue of gay men donating blood is currently the subject of an important civil lawsuit in Ontario.
In 2002, Kyle Freeman told Canadian Blood Services in an anonymous e-mail that he was a gay man who had donated blood on 18 occasions between 1990 and 2002.
The blood agency tracked down his identity and sued him for having lied on the blood donor questionnaire, specifically to question 19: "Male donors: Have you had sex with a man, even one time, since 1977?"
Mr. Freeman countersued, arguing that the question violated his right not to be discriminated against based on sexual orientation, which is guaranteed under section 15 of the Canadian Charter of Rights and Freedoms. He also asked the court to strike down the ban.
A ruling is expected this summer.