An HIV epidemic may be about to hit indigenous Canadians, an analysis of government data suggests.

Worldwide, HIV infection rates are higher among indigenous people than others – like many socially disadvantaged groups, indigenous populations are more likely to use intravenous drugs, and so more likely to catch the virus from contaminated needles, says Neil Andersson of CIET Canada, an epidemiological research and training organisation based in Ottawa, Ontario.

Andersson and colleagues’ analysis suggests that among indigenous Canadians, however, the virus has now moved beyond drug injectors, increasing the likelihood of an epidemic within the wider indigenous population.

The researchers studied over 13,000 new cases of HIV recorded by the Australian, Canadian and New Zealand governments across two time periods – 1999-2003 and 2004-08. The records document each patient’s sex, age, indigenous status, and how they were exposed to the virus.


Not just drug users

In Australia and New Zealand, rates of HIV diagnosis were similar among indigenous and non-indigenous people – although indigenous Australian women were three times (1999-2003) and six times (2004-08) as likely to be diagnosed with HIV as non-indigenous women. But the largest differences between the indigenous and non-indigenous populations were in Canada. Here, rates of diagnosis were four times higher in indigenous men than in non-indigenous men, and 14 times (1999-2003) and 20 times (2004-08) higher in indigenous women than in non-indigenous women.

“Many of the aboriginal [Canadian] women who became HIV positive were not intravenous drug users,” says Andersson. “The concern is what will happen next in indigenous communities there.” In Botswana and Swaziland, where the virus has advanced to the general population, 35 to 40 per cent of young women now have HIV.

Although indigenous Australian women were diagnosed with HIV at higher rates than non-indigenous women, the numbers are “very small”, says Frank Bowden at the Australian National University in Canberra, who was not involved with the study. For example, between 2004 and 2008 only 21 indigenous women were diagnosed with HIV. During the same period 460 indigenous Canadian women were diagnosed. “In Canada the situation is striking,” he says.

Bowden suspects that Canada indigenous drug users are “conduits” and are spreading the virus through sex with non-users. In Australia and New Zealand, by contrast, HIV rates are relatively low amongst this risk group, he says, thanks to widespread needle exchange programmes that began in the mid-1980s.

Journal reference: International Health, DOI: 10.1016/j.inhe.2011.03.010