Once somebody asked me why we can’t eradicate malaria by treating every person in malaria-endemic countries with an effective ant-malarial drug at the same time. As long as they all stay on the drug for as long as it takes for the current generation of infected mosquitoes to die (1-2 weeks on average, maybe a month maximum), then the human reservoir will be eliminated, no new mosquitoes will become infected, and that would be the end of malaria. It was an interesting idea, but who, exactly, was going to take on the task of putting every African on the same drug at the same time and making sure they stick with it long enough?
Now we are beginning to hear talk of a similar solution to AIDS. Can we eliminate AIDS without having either a vaccine or a cure? Some are starting to think the answer is yes.
Discussion has begun to gather momentum on an ambitious idea – eliminating AIDS through mass testing and early treatment. The idea, which was put forth in the Lancet journal by some experts at the World Health Organization is predicated on evidence that transmission of HIV is greatly reduced in people who are on anti-retroviral therapy (ART).
Basically the idea is as follows: If we start testing everybody routinely and frequently, then we can get a large proportion of carriers of the virus tested and on treatment quickly. If treatment is started soon after people have been infected, they will have little chance to transmit the virus, since the drugs will have reduced their viral load to levels that make transmission extremely difficult. If this is continued until the current group of carriers dies, for whatever reason, then the virus will be largely be eliminated from the population.
After years of frustration and failures, optimism is starting to grow. Funding for the disease has risen dramatically in recent years, a man may have recently been cured of AIDS, effectiveness of ART has started people thinking of HIV as a manageable chronic disease, and infection rates have begun to stabilize in many countries. This optimism has allowed researchers and policy-makers to begin thinking on a more ambitious scale.
But there are huge obstacles yet to overcome. Health systems in Africa continue to be in a miserable state. Delivering care to rural populations in countries with poor infrastructure has been notoriously difficult. With only 20% of HIV positive people in developing countries aware of their status, the task of testing them all would be an enormous (some would say impossible) undertaking. And what about treating them? Even with more funds for fighting global HIV/AIDS than we have ever seen and impressive increases in access to ART, only an estimated 13% of people needing treatment in Africa are receiving it. And as access to drugs increases, so does the specter of drug resistance.
There are still a lot of questions surrounding this proposal – on the science (Will transmission truly be cut if people are on ART? What about in places with high rates of other sexually transmitted infections?), on the feasibility (Where will the money for all these new tests and treatments come from? Can countries with extremely weak health care systems implement such an undertaking?), and on individual rights (Will people be coerced into taking the test without informed consent? What if testing is scaled up, but treatments are not available?). However, as long as we do not lose sight of other prevention interventions that have showed some results (such as public education on transmission of HIV, condoms, male circumcision, and treating other sexually transmitted infections), the potential benefits of using treatment as a tool for prevention are too promising to ignore.