The rapid scale up of highly active antiretroviral therapy (HAART) for HIV infection has been a global health success. On World AIDS Day (December 1, 2011), UNAIDS estimates we currently have 6.6 million HIV-infected people on antiretroviral agents (ARV), a number that was inconceivable less than a decade ago. Moreover, the rate of new infections has decreased substantially, by more than 25% in 33 countries, many in Africa. Finally, maternal-to-child transmission has dropped from an annual estimated 500,000 in 2001 to 390,000 in 2010.
Recently, the use of antiretroviral drugs for HIV prevention has commanded center stage.
The HPTN 052 landmark trial provided a jolt of optimism about how effectively ARVs can prevent HIV transmission. HIV-infected participants who received HAART had a 96% lower risk of transmitting HIV to their uninfected partner than those who delayed receiving HAART. Moreover, treated participants also suffered fewer HIV-related complications than those who delayed therapy. Talk about a win-win for both prevention and treatment.
So shouldn't we immediately ramp up access to HAART for everyone in the world who needs it? Of course we should. However, that's easier said than done. Providing universal ARV therapy globally will be expensive. By 2031, an estimated total of $35 billion will be needed to support HIV treatment services in low-resource settings. Even in the next three years, we will need another $6 billion (for a total of $22 billion) to meet the UNAIDS goal of universal access. Yet, in 2010, global AIDS funding was down nearly 10% from the previous year. In addition, the Global Fund for AIDS, TB, and Malaria just suspended awarding any new projects for 2011 because its coffers are low.
While resources dwindle, demand for ARVs continues to rise. Based on current WHO guidelines, nearly 8 million additional persons worldwide could benefit from being treated now. This implies that some form of implicit ARV rationing is already occurring. Our colleagues in resource-limited settings are currently facing ARV stock outs, and health systems are straining under the burden of caring for an increasing patient load. While we continue our utopian calls for universal access to ARV for all HIV-infected people, the world is faced with the grim realities of meeting the demands of present day clinical care.
So who gets the HAART? Right now, decisions are frequently made on a first-come, first-served basis. Many people learn they are HIV-infected when they already have HIV-related illness. They are put on treatment if the supply of drugs allows it. However, where supply is limited, we currently have no explicit guidelines to define criteria about who should be treated.
Thinking of ARV as prevention helps us establish such criteria. To optimize the impact of a limited supply of ARVs, policymakers should consider raising the priority for treatment of those individuals who both qualify clinically for ARV drugs and are most likely to spread HIV infection.
However, this approach raises moral, humanitarian and political problems. Those most likely to transmit HIV infection are frequently the most stigmatized populations in our society -- sex workers with many partners, men having sex with men in high-risk settings, migrant workers with multiple concurrent partners, injecting drug users in high-prevalence HIV injecting networks, and so on. Alternatively, those who society frequently perceive as "innocent" victims -- the HIV-positive monogamous sex partner or the HIV-positive young child -- are not as likely to transmit HIV infection to others.
In a public health model, to optimize limited ARV resources, we must proactively reach out to those HIV-infected persons most likely to transmit. Three specific advances can help achieve this. First, we need to do a far better job of identifying persons already HIV-infected. Second, we need better tools to diagnose acute HIV infection, when people are most infectious. Third, we need better protections for stigmatized, vulnerable HIV-infected populations, so they can play a more active role in prevention.
We must continue to advocate for raising the necessary funding to treat every infected individual. However, if we can't treat everyone, we must make hard choices with explicit criteria to determine who gets the HAART.