Some Canadian university groups are speaking out over what they feel are outdated and discriminatory screening practices for blood donors.

Several student groups and gay rights activists say they're particularly concerned about Canadian Blood Services' lifetime ban against blood donations from gay men. Their concerns largely stem from sections of a lengthy questionnaire potential donors need to fill out.

Question No. 18 of the blood agency's questionnaire asks potential male donors if they have had sex with a man, even once since 1977. If the answer is yes, even if the person has practised safe sex and is in a monogamous relationship, he or she is instantly deemed ineligible to donate.

"It makes people believe that, yes, gay men are likely to have HIV, likely to have AIDS," Andrew Brett, advocacy and outreach co-ordinator at the University of Toronto's student union in Mississauga, told CBC News. "It kind of makes it official, and it's like official discrimination."

The student federation doesn't condone banning blood drives on campuses although Brett noted that some student groups, including at York University in Toronto, have done so in the past.

Lorna Tessier, director of public relations with Canadian Blood Services in Ottawa, said she hasn't heard of any cancellations. "We collect regularly at those sites," she told CBC News on Wednesday.

Canadian Blood Services said it's reliant on student donations. "We are very dependent on being able to do blood donor clinics in universities," said Dr. Margaret Fearon, executive director of medical microbiology at the blood agency. She said students are mistaken to see the policy as a gay rights issue.

"People who receive blood have a right to safe blood. People do not have a right to donate blood. It's a privilege, really."

Many countries are struggling with the issue, in addition to Canada. In the U.S., a lifetime ban on men who have had homosexual encounters was upheld earlier this year, even though the American Red Cross recommended a change.

According to Tessier, Canadian Blood Services has begun research into whether more specific questions about risky behavior would be a better addition to the screening process.

Dr. Steven Klinman, senior medical advisor with the American Association of Blood Banks, said that a lifetime ban isn't necessary because HIV testing is so accurate now. But he said recent sex between men still presents a risk blood agencies can't ignore.