The life expectancy of Canadians and Americans who are HIV positive is closing in on that of the general population, a new study reveals.

It suggests that 20-year-olds diagnosed with HIV today can expect to live into their early 70s.

That is a sharp contrast to the early days of the AIDS epidemic, when a diagnosis of HIV was a death sentence.

People who contracted the disease often died within months or at best a few years, their bodies ravaged by opportunistic infections their demolished immune systems could not quell.

But with the discovery and improvement of antiretroviral drugs, HIV has become a chronic disease for most who have access to and can afford the medication.

The newer generation of drugs also has fewer side-effects, allowing them to be better tolerated and increasing the chances people prescribed the drugs take them as ordered.

They are “simpler and safer and better tolerated, so people are able to take these treatments better and also for a longer period of time,” said Dr. Julio Montaner, a leading HIV researcher.

Montaner is director of the B.C. Centre for Excellence in HIV/AIDS, which led the research collaboration that produced the study.

He said the longevity gains have been remarkable. In 2000, the average 20-year-old newly diagnosed with HIV could expect to live another 36 years. By 2006, that figure had climbed to 51 years.

“I don’t think, in all honesty, that there has been an area of medicine that has undergone (as big a) revolutionary evolution over our lifetime as HIV has,” Montaner says.

The substantial gains haven’t been made across the board.

HIV-positive injection drug users still have lower life expectancies than men who have sex with men. And non-whites have lower life expectancies than HIV-positive people who are white, the study said. Dr. Ann Stewart, medical director of Toronto’s Casey House, said the findings mirror what her staff sees in its patient population. Casey House started 25 years ago as a hospice for dying AIDS patients. As treatment has prolonged the lives of the community it serves, the facility has transitioned into a hospital that offers care for people living with HIV.

Stewart warned, though, that the picture is not an “unclouded” one, noting HIV-positive people often develop the health problems of age faster than those who are not infected.

So heart disease, cancers and the onset of cognitive decline that might be expected in the late 60s, 70s or even 80s in HIV-negative people can show up a decade or two earlier in HIV-positive people, she said.

“We see our folks at 50 feeling a lot older than the average population would feel at that age,” said Stewart, who added that conditions vary depending on how long people have been infected and how religiously they have taken their medication.