The blood-donation deferral period for gay and bisexual male donors is dropping from one year to three months in Canada.

Health Minister Ginette Petitpas Taylor made the announcement on Parliament Hill in a move that was foreshadowed late last year.

"Today, we're taking a major step towards a fair, evidence-based blood-donation system by reducing the deferral period to three months and moving towards behavioural-based screening." said Petitpas Taylor.

The new guideline means that a gay or bisexual man has to abstain from sex with other men for three months before he can donate blood.

Today, we’re taking a major step towards a fair, evidence-based blood donation system by reducing the deferral period to three months and moving towards behavioural based screening. —@GinettePT

The announcement marks the latest change in the Health Canada and Canadian Blood Services (CBS) policy, which was introduced in 1992 as an outright ban on blood donation by gay and bisexual men after thousands of Canadians were infected with HIV and hepatitis C through tainted blood products.

The lifetime ban was lifted in 2013 when Canada moved to a policy that allowed donations from men who said they had abstained from sex with other men for five years. In 2016, the deferral period was reduced to one year.

The blanket deferral for men who have sex with men has been criticized by a number of groups and individuals, including lawyer Christopher Karas, who filed a human rights complaint about the matter in 2016.

Christopher Karas says today's announcement by Health Canada is nothing to cheer about because the blood donor screening process remains fundamentally flawed. (Evan Mitsui/CBC)

Karas said Wednesday the news is nothing to cheer about, because the underlying premise of CBS donor screening is fundamentally flawed.

"We've seen incremental steps that, frankly, don't get to the heart of the matter, which is that these policies are not based on behaviour. These policies target groups and don't allow those groups to donate blood for discriminatory reasons," said Karas.

Kat Lanteigne, head of the safety watchdog group Blood Watch, says the best way to protect Canada's blood supply is to screen for behaviours that might put individuals at risk of HIV infection, rather than labelling entire groups as high risk donors. (Kat Lanteigne)

Karas points to the CBS blood-donation questionnaire, which asks under the heading "lifestyle" if a potential male blood donor has had sex with another man.

"I find that very discriminatory and homophobic," he said.

Independent watchdog group BloodWatch.org said although it supports Wednesday's announcement, it's also asking Health Canada and CBS to change the donor-screening process.

"Our perspective is that if you have a behaviour-based donor deferral in place, that is the safest way to operate a public health system," said BloodWatch.org executive director Kat Lanteigne.

"It would change what currently happens, in that there wouldn't be a blanket ban on [men who have sex with men] and a blanket deferral of three months. It would mean that any individual — whether they are MSM [men who have sex with men] or trans [transgender] or a single woman or a married person — gets asked the same questions and are deferred based on their behaviour."

CBS considers men who have sex with men a high-risk group, as they account for the largest proportion of new HIV infections reported in Canada.

In 2017, MSM accounted for 46.4 per cent of the 2,402 new HIV cases reported in Canada.