TORONTO - A quarter-century after AIDS burst on the world's radar as it began ravaging gay male populations in North America, public health authorities in a number of developed countries are seeing a disturbing trend.

Rates of HIV infections among men who have sex with men are on the rise, reversing years of declining rates in that community.

As World AIDS Day approaches, several leading public health authorities raised the politically touchy topic in a commentary published Wednesday in the Journal of the American Medical Association, asking why infection rates among this group of individuals are rising and what can be done to stem the trend.

"The tragedy of the epidemic for an earlier generation of MSM must not be repeated," they argued, using the public health community's shorthand -- MSM -- for men who have sex with men.

The authors are Dr. Harold Jaffe, director of the department of public health at Oxford University, Dr. Kevin de Cock, head of HIV-AIDS at the World Health Organization and Dr. Ronald Valdiserri, chief consultant to the public health strategic health care group of the U.S. Department of Veterans Affairs.

The commentary looks only at trends in western countries, where men who have sex with men have always made up the lion's share of people living with HIV-AIDS.

They noted there was a 13-per-cent increase in American MSM living with HIV-AIDS between 2001 and 2005. A 10-fold increase in syphilis cases among MSM in the United States over the same period is further evidence of an increased frequency in unprotected sex, the authors said.

HIV-AIDS rates among men who have sex with men are also in the increase in Canada.

David Boulos, a senior epidemiologist with the Public Health Agency of Canada, said Tuesday that MSM accounted for only about 37 per cent of new HIV infections in this country in 1996, an all time low. But since then the rate has again begun to climb, reaching about 45 per cent in 2005.

Jaffe and his co-authors suggest the reversal is at least in part the product of complacency.

"Our feeling is that there's now a complacent attitude towards the epidemic in general and particularly in gay men. Somehow it's just being accepted that yes, of course, the epidemic is continuing," he said from Oxford.

They also note that breaththroughs in drug therapy for HIV-AIDS have lessened the panic that gripped the gay community in the early days of the epidemic.

Dr. Philip Berger, one of the original Toronto physicians who treated - and still treats - HIV patients, agreed.

"The availability of six classes of anti-HIV drugs represents a certain security and protection that people know is out there in case they became HIV infected," said Berger, who practises at Toronto's St. Michael's Hospital. Berger was not involved in the commentary.

"And therefore people might be less inhibited than they were in the days when there was no therapy."

A related contributing feature, Jaffe and others suggested, is the fact that gay men today don't see the physical toll AIDS extracted before the era of antiretroviral drugs. The wasting. The disfiguring Kaposi sarcomas that virtually branded many men dying from AIDS.

"The crushing consequences of the infection are not visable on the streets in the way they were in the 1980s, so that people are not constantly reminded of the devastating effects of AIDS in the way it was seen back then," Berger said.

"They don't see it now."

The authors suggested another part of the problem is the fact that too few people who are HIV positive know their status - a reality that concerns Dr. Julio Montaner, president-elect of the International AIDS Society and director of the B.C. Centre of Excellence for HIV-AIDS.

Montaner said that in Canada today, 20 to 30 per cent of people infected with HIV don't know they carry the virus. He suggested the problem persists because of a failing of political leadership - a shortcoming he believes is also responsible for a lack of effective HIV-AIDS prevention campaigns.

"The problem is that the safer sex message wears out," he said from Vancouver.

"Coca Cola sells because every six months they reinvent themselves," Montaner noted. "What about our safer sex campaigns? Hello! First, they are not there. Second, they are boring."

While Montaner believes the failure of leadership rests with elected politicians, Jaffe and his co-authors said it was time for gay community to step up HIV prevention efforts.

"The mid-80s were characterized by great activism within the gay community at a time where there was essentially no federal funding for AIDs. And the gay community took it upon themselves to say: 'We're killing ourselves. We have to do something.' And they did," Jaffe noted.

"And that activism isn't there anymore.... There really isn't much activism now for HIV prevention, even though the number of men getting infected . . . in the U.S. and western Europe is going up, not down."