Canadians win international recognition with new HIV test

Tests de résistance aux médicaments du VIH

The NGS-based platform for HIV drug resistance testing developed in Canada with the support of GRDI funding is already being rolled out for use in sub-Saharan Africa and other regions. Here, participants in a workshop at the Uganda Virus Research Institute in Entebbe, co-sponsored by the PHAC National HIV and Retrovirology Laboratories, receive hands-on training in the new test.
(Photo credit: J. Nazziwa, UVRI)

In Canada—assuming early diagnosis and access to proper treatment—the life expectancy of a person infected with HIV is now almost the same as an uninfected person.

This is not to say HIV—the human immunodeficiency virus that leads to AIDS—is to be taken lightly.

There is still no cure for AIDS and the number of people infected with HIV continues to rise. According to the Public Health Agency of Canada (PHAC) there's a new HIV infection in Canada every three hours Footnote 1. Globally, the World Health Organization (WHO) estimates that another two million people around the world were infected with HIV in 2014 alone, and more than 1.2 million people died of AIDS-related illnesses Footnote 2.

Progress, but significant challenges

At the same time, the rate at which HIV is spreading has slowed considerably—the number of new HIV infections in 2014 was 35 percent lower than it was in 2000 Footnote 3. The WHO has determined to end the epidemic and eradicate HIV/AIDS by 2030.

Achieving that goal means overcoming a number of barriers, not least of which, as Dr. Paul Sandstrom explains, is tracking and addressing drug resistance in HIV.

"This has been the difficulty with HIV from the beginning," says Dr. Sandstrom, Director of the PHAC National HIV and Retrovirology Laboratory in Winnipeg. "You can treat it successfully with one set of drugs, but the virus can mutate and may become resistant to those drugs. Understanding the emergence and transmission of drug resistance virus will be critical for countries to achieve UNAIDS treatment targets by the year 2020.

Canada part of global network

Dr. Sandstrom's labs in Winnipeg and Ottawa are part of the WHO's HIV ResNet. This global network is developing new strategies to monitor for and respond to drug resistance in the virus before it becomes established in a population, setting off a new epidemic of untreatable HIV.

The challenge is especially great in sub-Saharan Africa, where a lack of resources, poor public health infrastructure and other barriers make it difficult to provide appropriate HIV treatment consistently—which increases the likelihood of HIV developing drug resistance. These barriers also make it harder to do the ongoing testing needed to identify drug resistance in HIV at an early stage.

Canadian researchers, funded by the Government of Canada's Genomics Research and Development Initiative (GRDI), have taken a large step toward resolving this problem—a DNA-based test platform for identifying drug resistance in HIV that is faster, more sensitive and less expensive than anything now available. The new test is already being rolled out in Africa and other parts of the world.

How it works

"You can test for HIV drug resistance by taking a blood sample from a patient, freezing the plasma and delivering that to a specialized lab for testing," says Dr. Sandstrom. "In Canada, that's easy to do. In sub-Saharan Africa, where the transportation network is nothing like what we have here, freezing plasma and keeping it frozen until you find a lab with the resources to do the testing can be extremely difficult."

Dr. Sandstrom's team first pioneered a test that used a spot of dried blood instead of plasma. Then, with the advent of next-generation sequencing for DNA, the team was able to move to the next level.

"With NGS, you can test dozens of samples at once, so it's faster and less expensive," says Dr. Sandstrom. "It is also much more sensitive, allowing you to diagnose drug resistance far earlier in the process. With the old method, 25-30 percent of the HIV virions would have to show drug resistant mutations for the test to pick up on it. With NGS, even if only 1-2 percent of the virus has mutated, you'll see it."

The bioinformatics capacity developed in tandem with the test means the Canadian team has also provided the WHO with a more effective way to monitor drug resistance in different populations and take action before it reaches a critical level.

Proud for Canada

Dr. Sandstrom says the NGS test platform for HIV drug resistance has brought international recognition to Canada, with special praise for the leaders of the project, Dr. Hezhao Ji and Tracy Taylor from the National HIV and Retrovirology Laboratory in Winnipeg.

"This a great example of the kind of positive influence Canada can have in the world," says Dr. Sandstrom. "It's going to make a real difference in peoples' lives and play an important part in the global effort to eradicate HIV."

Footnotes

Footnote 1

extrapolated from PHAC publication Summary: Estimates of HIV incidence, prevalence and proportion undiagnosed in Canada, 2014 (new infections in 2014 estimated as high as 3,200)

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Footnote 2

ONUSIDA. Fact Sheet 2015

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Footnote 3

ibid.

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