HIV strains mutating in Saskatchewan
Strains of the HIV virus have mutated in Saskatchewan, placing individuals who contract HIV in the province in danger of quickly progressing to life-threatening, AIDS-defining illnesses if they are not taking HIV antiretroviral therapy.
HIV incidence rates in Saskatchewan are among the highest in North America, with 2016 rates in some regions more than tenfold higher than the Canadian national average. And Saskatchewan physicians have been reporting an unusually rapid progression from HIV to AIDS among those who have not sought treatment. AIDS is the last and most severe phase of HIV infection.
These reports sparked the first molecular epidemiological study of HIV in Saskatchewan, with findings presented today at the AIDS Conference in Amsterdam.
SFU Health Sciences professor Zabrina Brumme led the study with researchers from the BC Centre for Excellence in HIV/AIDS, SFU, the Public Health Agency of Canada (PHAC), as well as Saskatchewan physician-researchers.
The study’s findings show that HIV strains circulating in Saskatchewan have adapted to evade and undermine host immune responses. These genetic mutations are being transmitted frequently and, when HIV is left untreated, can accelerate the disease’s progress.
The multi-year analysis compared more than 2,300 anonymized HIV sequences from Saskatchewan with data sets from sites across the United States and Canada. Genetic analyses of HIV strains in Saskatchewan showed high levels of clustering—indicating that viruses with similar mutations are being frequently and widely transmitted. Seventy-eight per cent of Saskatchewan HIV strains reside within transmission clusters compared with only 15 per cent of HIV strains found elsewhere in North America.
Brumme says the researchers were startled by the prevalence of immune-resistant mutations. One key mutation was found in more than 80 per cent of Saskatchewan HIV strains, compared with only about 25 per cent of HIV strains found elsewhere in North America. The pervasiveness of such mutations is increasing over time: more than 98 per cent of the HIV sequences most recently collected in Saskatchewan (between 2015 and 2016) harboured at least one major immune-resistant mutation.
Saskatchewan's HIV epidemic is unique in that nearly 80 per cent of infected persons self-identify as having Indigenous ancestry. As well, according to the Saskatchewan Health Authority, 60 per cent of people who have HIV in Saskatchewan either inject, or have injected, drugs.
“The study’s findings are concerning, but individuals can take action to protect their own health,” says Brumme. “It is important for everyone to get tested regularly for HIV and to seek and receive HIV care and treatment if they test positive.
“If taken correctly, antiretroviral therapy prevents the virus from mutating and from being transmitted. With antiretroviral therapy, people with HIV can live long and healthy lives.“