People who regularly smoke crack cocaine have a significantly higher risk of becoming infected with HIV, warn Canadian researchers, who say use of the drug has risen dramatically across the country in the last several years.

In a nine-year study of drug users in Vancouver's Downtown Eastside, researchers found that those who reported smoking crack daily were four times more likely to become infected with HIV than drug-using peers who smoked crack less often or not at all.

"Approximately 10 years ago, about 10 per cent of drug users in the Downtown Eastside were using crack cocaine -- and by the end of the study period, 40 per cent were using crack cocaine daily," principal investigator Dr. Evan Wood of the B.C. Centre for Excellence in HIV-AIDS said Monday from Vancouver.

"So we've seen a massive increase in the use of crack cocaine," said Wood, adding that the findings point to an urgent need for innovative public-health programs targeted at crack smokers.

Startling results

To conduct their study, researchers looked at data from 1,048 people in the Vancouver Injection Drug Users Study, all of whom were HIV-negative at the time of enrolment. Nine years later, in 2005, 137 of those participants had contracted the virus that causes AIDS.

While researchers were not able to determine the exact link between crack smoking and the elevated risk for HIV, they say mouth wounds caused by crack pipes make people more vulnerable to infection and the association with a higher number of HIV-positive individuals could boost the likelihood of infection through sex and needle sharing.

Wood said drug users in Vancouver and elsewhere in Canada often smoke crack using homemade pipes that contain sharp metal that cuts the lips and mouth or glass that burns the area when heated to high temperatures for smoking.

"And, of course, this is the same population that's sharing pipes ... (and) engaging in sex-trade activity, so getting exposure to bodily fluids where HIV is present," he said.

Harm reduction and the European connection

Wood and his fellow researchers, whose study is published in this week's issue of the Canadian Medical Association Journal (CMAJ), say harm-reduction programs are needed to prevent the spread of HIV among the growing number of crack users.

Although controversial, those programs could include distribution of crack cocaine kits and provision of safe inhalation rooms for users.

In several European countries, inhalation rooms are operated as supervised health-care facilities that provide safe and hygienic conditions for drug use. Early reports suggest that bringing the drug-using population under the public-health umbrella creates opportunities for health workers to offer addiction treatment.

In contrast, Wood said, the United States has spent an estimated $1 trillion in its war on drugs and has more drug users per capita in prison than any other country in the world. Despite the incarcerations, the rate of drug use has not fallen, the crack supply has risen and its price has dropped dramatically, he said.

"I certainly look at the successes they've had in Europe and the problems with the U.S. approach and think this is something we should design a study to test in Vancouver," he said.

That could be a hard sell, especially to the federal government.

Fighting the battle

Vancouver is home to North America's only supervised centre for injection-drug users -- but the Conservative government under Prime Minister Stephen Harper is trying to shut its doors for good.

Ottawa has challenged a B.C. court ruling that would have allowed the Insite facility to remain open. The B.C. Appeals Court is expected to rule on the case soon.

In a CMAJ commentary, doctors David Celentano and Susan Sherman of Johns Hopkins Bloomberg School of Public Health write that "with the increasing proportion of injection drug users who are smoking crack cocaine, harm reduction programs need to address the unique needs of these people as part of a comprehensive HIV prevention strategy."

"Although controversial, the distribution of 'crack kits' (glass stem with mouthpiece, metal screen, lip balm and hand wipes) to this population has the potential to reduce HIV transmission."

Wood said a four-fold increased rate of HIV among crack smokers should be raising alarm bells in Canada -- especially for governments that set public-health agendas.

"The genie is out of the bottle in terms of this virus," he said. "It's no longer constrained to traditionally high-risk populations."

"And if we're going to put that genie back in the bottle, we need to start implementing pragmatic and evidence-based public health strategies."