Dr. Micheal Rekart wants to take advantage of new blood tests that detact HIV DNA and that become positive within days - photo by Martin Dee
UBC Reports | Vol. 54 | No. 1 | Jan. 3, 2008
NBT: Saying Goodbye to HIV in Canada
By Dr. Michael Rekart
Clinical Professor, Director, STI/HIV Prevention and Control, British Columbia Centre for Disease Control
At the risk of sounding like a cockeyed optimist, I can see a time in the not too distant future when the human immunodeficiency virus, HIV, has been all but eliminated from Canada. And the weapons that we need to win this long-running war against this elusive adversary are not still “under development” in the research laboratory -- they’re actually already at hand.
HIV is a lifelong infection during which the virus levels in the blood stream and other bodily fluids ebb and flow, in much the same way that a patient’s symptoms can vary from time to time. However, it’s clear that the largest viral loads occur during the early and late stages of infection. Since the risk of transmission to someone else correlates with the amount of virus, an infected person poses the greatest risk of spreading HIV during the early and late stages. It would be logical, therefore, to target these highly infectious individuals with an enhanced focus on preventing such transmission. But that’s not such an easy thing to do.
During the late stages of infection, most patients qualify for free anti-retroviral (ARV) treatment which lowers their viral load and risk to others. But half of these individuals, currently, are not actually taking ARVs. Drug cocktails (commonly called HAART -- highly active retroviral treatment) can be difficult to take, cause serious side effects and generate drug resistance. Furthermore, many people who require treatment have significant problems in accessing the health care system in the first place. Many of them struggle with more immediate difficulties like drug addiction, poverty, poor housing, discrimination and abuse.
Dr Julio Montaner, Director of the BC Centre for Excellence in HIV/AIDS, believes that it’s possible to improve this situation through directly-observed therapy and once-a-day HAART regimens which are less toxic but currently more expensive.
On the other end of the continuum, HIV levels in a person during the first few weeks of infection, the acute phase, can be 28 times higher than during the latent phase which lasts eight to 10 years. Since the standard HIV blood test measures antibodies against HIV and thus takes four weeks to turn positive, you might think that this critical period is unassailable. But you would be wrong, because blood tests that detect HIV DNA and that become positive within just a few days of infection have been approved in Canada for several years now.
These diagnostics are called the nucleic acid amplification tests (NAATs) and these are what Canadian Blood Services uses to screen blood and tissue donations. The Sexually Transmitted Infection (STI) and HIV Prevention and Control Division at the British Columbia Centre for Disease Control (BCCDC) has just been awarded a $2.5 million grant from the Canadian Institutes for Health Research (CIHR) to pilot the use of NAAT to identify and intervene for acute infections in Vancouver.
Imagine how the current HIV infection/transmission scenario could be turned around if we were able to identify infections within days rather than weeks. People who do get infected would be aware of their status much, much sooner, allowing them to take precautions against infecting others at a much earlier point in time as well -- and ultimately empowering them to begin taking better care of their health overall, to live healthier and longer lives.This push to ensure early detection also ties in with overall HIV prevention advocacy, especially when it comes to getting people to get tested.
On a related note, it appears that the role of herpes simplex virus type 2 (HSV-2) as a cofactor in up to 40 per cent of HIV transmissions can be mitigated by scaling up HSV-2 education, diagnosis, treatment and prophylaxis programs with new lab tests and generic drugs already available. HIV doesn’t exist in a vacuum -- and by better recognizing and addressing this, we can make significant progress in reducing HIV infection and transmission.
By aggressively targeting the early and late phases of HIV infection and by dealing more proactively with HSV-2 infection, I believe we can -- and will -- make HIV a thing of the past.