The journal Science named it the breakthrough of 2011 and Time magazine ranked it among its Top 10 medical breakthroughs of the year, so you may have heard of the term "treatment as prevention" by now. If not, we can fill you in. It has at its core the idea that HIV treatment can reduce the risk of HIV transmission, and it is set to mark a historic shift in how we think about the HIV epidemic.
When effective antiretroviral treatment became available in 1996, forward-thinking researchers began speculating that the drastic drops in viral load that occur when people with HIV take treatment might reduce the risk of passing the virus to others. But there was no evidence to back up the idea. In the past few years, as more and more studies confirm this theory, the distinction between treatment and prevention has become increasingly blurred. Last year the strongest evidence supporting the use of treatment as prevention was announced: A study known as HPTN 052 demonstrated that starting antiretroviral treatment earlier could dramatically reduce the risk of HIV transmission among serodiscordant heterosexual couples (in which one partner is HIV positive and the other is HIV negative) -- by 96 percent. Some researchers now say that treatment IS prevention, and we are hearing bold claims that the end of the epidemic is within sight.
In real-life terms, treatment as prevention involves getting more people with HIV diagnosed and on treatment. While ending the epidemic is a laudable goal, what does this mean for individual people with HIV -- the people who face every day the reality of living with the virus and being on HIV treatment? There are concerns that these public health efforts may come at the cost of the rights of HIV-positive people. At the same time, treatment as prevention could improve access to the services needed for people with HIV to live healthy lives.
We can think of treatment as prevention in two ways: as a prevention strategy for individuals and as a public health strategy. Both have implications for people living with HIV and each raises its own set of issues.
A prevention strategy for individuals -- An HIV-positive individual may want to use treatment to reduce his or her risk of passing HIV to others. Research shows that people living with HIV who are on treatment and have an undetectable viral load are, on average, less likely to pass HIV to others. However, there are several caveats and gaps in the research, which make it difficult to know exactly how well this strategy would work for each individual. (For more on viral loads and the biology of HIV transmission, check out "Sex, Drugs and Viral Load" in the Winter 2008 issue of The Positive Side.)
A public health strategy -- Since we know that treatment can reduce the risk of an individual transmitting HIV to his or her partner, it follows that increasing the number of people on treatment in a community prevents a large number of transmissions. The overall goal of treatment as prevention from a public health perspective is to increase the number of HIV-positive people with an undetectable viral load in a population and thereby decrease the number of new infections.
A major challenge to the success of such a public health strategy is the large number of people who are HIV positive but don't know it. In Canada, about one quarter of people living with HIV are unaware of their status. If people don't know they are HIV positive, then they can't consider starting treatment and are unlikely to have an undetectable viral load.
To tackle this issue, health officials have developed a "seek, test and treat" strategy, whose goal is to seek out undiagnosed individuals, test them for HIV, and treat those who test positive and are ready to start antiretroviral therapy.
Increasing the number of people who get tested is good for both the health of people with HIV and for HIV prevention. For people living with HIV, it can mean getting diagnosed sooner and getting the treatment and support they need. (Many people in Canada aren't learning about their status until they are in the late stages of HIV infection and this often means worse health outcomes.) For HIV prevention, more testing can mean diagnosing more people at an earlier stage of infection. People can then take steps to prevent passing the virus.
Reactions on the ground have been mixed: Treatment as prevention has been hailed as a "game-changer" but some worry about the potential for coercion and that services may focus exclusively on testing and treatment.
Ken Monteith, the executive director of COCQ-SIDA in Montreal who was diagnosed with advanced HIV in 1997, has concerns that a treatment as prevention strategy could potentially pressure or mislead people into getting tested and starting treatment for the sake of broader public health goals. "When I hear 'seek, test and treat,' it sounds aggressive to me. We need to make sure that a person consents to being tested and to starting treatment," he says. "People must have the right to say no. We need to make sure that measures are in place for people to have their decisions respected and to make those decisions based on complete information about the advantages and disadvantages of being tested and starting treatment."
The Canadian HIV/AIDS Legal Network's executive director, Richard Elliot, is worried about the shift to routine testing and about "opt-out" testing (where a healthcare provider tests unless the client or patient refuses). "The healthcare provider should always ask if you would like to be tested and testing should only be done if the person accepts that offer, rather than just presuming that someone consents to an HIV test unless they specifically say they don't want one. This is an ethical obligation and a human right."
Elliott also stresses that informed consent requires that people be aware of the possible negative consequences of testing positive for HIV. For example, he notes that people with HIV can be criminally prosecuted for not disclosing their HIV status to sexual partners and that there is a possibility for health information, including a person's HIV status, to be shared. He says that these "are things people need to understand in order to make an informed decision."
Even when testing is "opt-in," the issue of informed consent isn't always straightforward. For example, the four major acute-care hospitals in Vancouver now offer an HIV test to each and every person who is admitted. As Marcie Summers, executive director of the Positive Women's Network in BC, points out, "If you've been admitted with a case of acute appendicitis, are writhing around in pain, and someone offers you an HIV test, how informed will your consent be?"
To further the aims of the public health approach to treatment as prevention -- increasing the number of people on treatment -- another strategy is to have people with HIV start treatment earlier than current treatment standards.
Many guidelines in developed countries currently recommend starting treatment when a person's CD4 count drops below 500. However, in light of the recent evidence that starting treatment earlier may improve the health of people living with HIV and lower the risk of transmission, the U.S. Department of Health and Human Services, which produces the granddaddy of HIV treatment guidelines, recently changed its guidelines to recommend starting treatment in all HIV-positive people who are ready to start. In the UK, guidelines released earlier this year do not recommend earlier treatment but advise clinicians to discuss with everyone who tests positive the potential for treatment to reduce HIV transmission. Quebec's HIV treatment guidelines acknowledge that treatment could be considered for lowering the risk of HIV transmission, and updates to the guidelines, currently underway, are expected to address in greater depth the concept of treatment as prevention.
This movement toward recommending treatment earlier has been met with some criticism. "The worry is that treatment is being suggested earlier than is generally indicated for the benefit of the patient," says Monteith. "Putting someone on treatment for the benefit of the public, and not primarily for the benefit of the person living with HIV, is ethically questionable."
Murray Jose, executive director of the Toronto People With AIDS Foundation and living with HIV for 21 years, is also concerned. "These changes represent a fundamental shift toward a public health approach to treatment instead of focusing on the well-being of the person living with HIV," he says. "The evidence isn't conclusive that the health of a person with HIV is going to be improved by starting treatment earlier. In fact, it's possible that the opposite is true because these drugs can be toxic and we don't know a lot about their long-term side effects, particularly for the newer medications."
Despite these concerns, Jose recognizes that giving people the option to start treatment earlier to reduce their risk of transmitting HIV to their sex partner(s) is important. "People living with HIV should absolutely be given all the options. But I worry that newly diagnosed individuals may feel unduly pressured to start treatment in order to reduce their risk of passing HIV to others."
AIDS service organizations from coast to coast to coast have long known the value of providing holistic care to people with HIV. Testing and treatment are crucial pieces of the puzzle but not the whole story. Many people with HIV look for different kinds of support when they are first diagnosed and also when they decide to start treatment. A holistic approach can help people stay connected to their care team, stick to their pill-taking schedules, provide emotional support and ensure that more people achieve an undetectable viral load.
Jose believes that engagement in care needs to improve in Canada. "There is just no excuse for the poor access to prevention and treatment services that exists in Canada, particularly among Aboriginal populations, prisoners and newcomers to Canada," he says. "If we can use this new evidence on treatment as prevention to push for improved access to services, then that's great, but the focus and motivation needs to be the health and well-being of the person living with HIV, not just prevention."
Dr. Julio Montaner, director of the BC Centre for Excellence in HIV/AIDS and a lead proponent of treatment as prevention, has been a driving force behind a pilot project in BC called STOP HIV/AIDS. The project, focused on Vancouver and Prince George, aims to cut HIV transmissions by expanding HIV testing, treatment and support services.
Marcie Summers has had the opportunity to learn about STOP HIV/AIDS and to see treatment as prevention in action. "One of the main goals of the project is not just to increase HIV testing but also to engage people living with HIV in care. Quite a few of the initiatives that are part of the STOP HIV/AIDS project are improving engagement in care quite effectively, particularly for people who have fallen through the cracks of our healthcare system. This includes people who have tested positive and haven't accessed healthcare or people who were on meds and went off them for some reason. There was initially a lot of skepticism about STOP, and there still is, but there are some really good initiatives going on."
STOP HIV/AIDS is a concrete example of the momentum that is building toward a shift in HIV policies and programs. Promising research on treatment as prevention has led to strong arguments for better integrating treatment and prevention services, but the rights of people living with HIV need to be at the centre of this new approach.
The Legal Network's Richard Elliott thinks this is possible: "Public health goals and human rights are largely complementary. Achieving the highest attainable state of health for the individual and for all individuals are human rights goals. In the big picture, if you go about pursuing public health goals without protecting and respecting the human rights of individuals, then people's trust in the health system will erode and achieving HIV prevention goals is going to be more difficult. Scaling up treatment should be done both because it's good for individuals who need treatment and because we know that treatment is a way to protect public health more generally."
Read more about the HPTN 052 study in CATIE's TreatmentUpdate 185.
Illustrations by Kelly Schykulski.