The prevalence of HIV in Vancouver is estimated to be about 1.21 percent, roughly six times higher than Canada's national prevalence, with some groups in the city having HIV at radically higher rates, according to a new study. Among the city's female sex workers, HIV prevalence is 26 percent, and prevalence was 17 percent among injecting drug users, according to researchers with the British Columbia Center for Excellence in HIV/AIDS. Among gay men, HIV prevalence was estimated at 15 percent.

The study is based on 2006 Statistics Canada data and other sources, population surveys, and UNAIDS and World Health Organization estimation and projection software.

"Drugs and sex are the preferred routes for transmission," said study co-author Dr. Julio Montaner, president of the International AIDS Society and head of the division of HIV/AIDS at the University of British Columbia. "Female sex trade workers get paid more money for having unprotected sex with johns."

"We always knew we had a significant problem, because of factors like our benign climate causing people to drift here, being a port city, and having so much poverty and so many homeless people on the Downtown Eastside," Montaner said.

HIV experts have suggested to provincial officials seeking out and treating HIV-positive people who are not yet taking antiretroviral drugs, Montaner said. Less than a third of the estimated 13,000 British Columbia residents with HIV are on treatment. Boosting the treatment number to about 7,500 would reduce the number of new HIV infections annually from 400 to 300, he said.

"The premier, the health minister, and other government officials have been very supportive about this kind of progressive approach," said Montaner. "But now with the economic downturn, we are in a waiting mode."

The study, "HIV/AIDS in Vancouver, British Columbia: A Growing Epidemic," was published in Harm Reduction Journal (2009;6(5):doi:10.1186/1477-7517-6-5