How HIV Treatment and Prevention Programs Succeed Together

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When public health officials debate the most effective HIV programs, generally two broad camps emerge: prevention and treatment. Test-and-treat programs seem to offer a catchall benefit to society. Researchers have clearly established that the benefit of antiretroviral treatment go beyond the individual -- patients on treatment with low viral count are unlikely to transmit the virus, or what's known as treatment as prevention.

For this reason, it can be tempting to focus public health efforts on test-and-treat programs, and neglect traditional prevention such as condoms, male circumcision and behavior change. While test-and-treat programs should be encouraged, they should compliment, not replace, traditional prevention programs.

During a presentation at IAS 2015, Francois Venter, M.D., from the Wits Reproductive Health and HIV Research Institute, described implementations and challenges of various biomedical interventions, and detailed his own work in South Africa.

Highlighting Areas of Focus

There are about a half-dozen biological interventions that public health officials typically employ to combat HIV. One of the most successful models is called test and treat, in which every effort is made to identify HIV-positive individuals and start them on antiretroviral therapy right away. Pre-exposure prophylaxis (PreP) has also been a runaway success story in terms of its efficacy, but the drugs remain inaccessible for many patients because of the high cost. Male circumcision is also an effective preventative measure, but Venter calls it, "a bit of an orphan" that needs more attention. There are others, including post-exposure prophylaxis (PEP), condoms and needle exchange -- but these were not among the interventions highlighted by Venter in his presentation.

Test and Treat Works

The concept of test and treat started off with a simple observation: viral load is correlated with infectiousness. In fact, Venter pointed out that if antiretroviral threapy was boosted by just 1% among HIV-positive adults, this would translate into a 1.7% decline in the risk of HIV acquisition in the rest of the population. As studies, such as HPTN 052, have shown -- risk of HIV transmission during condomless sex is extremely low when the HIV-positive individual's viral load is suppressed with antiretroviral therapy. The currently available drugs are so powerful that multiple randomized controlled trials found a statistically significant benefit of test and treat as a public health initiative, according to Venter.

PrEP Alters the Prevention Mindset

PrEP has "electrified" the HIV community, Venter said. The stunning success of this once-daily pill proved that condoms were simply not good enough to halt the spread of the virus. PrEP falls under the traditional purview of "prevention" public health initiatives, but it carries with it a certain connotation. As the treatment becomes increasingly available across the globe, Venter warns that stigma may be associated with PrEP, and stigma is a significant barrier to effective prevention initiatives. But today, PrEP remains out of reach because its hefty price tag is prohibitive to many prevention programs around the world.

Circumcision, an Orphan Prevention

Even though male circumcision tends to be overlooked, the data overwhelmingly shows that the procedure is an effective way to reduce the risk of HIV transmission. Thankfully, this practice is being adopted in the 14 priority African countries. In 2014 alone, 3.3 million men in these countries were circumcised -- a 22% increase over 2013. However, the HIV fund PEPFAR has a slight decrease in funds available for circumcision. If a program is working, it should not be curtailed, Venter said.

Test and Treat vs. Traditional Prevention

There are many reasons to emphasize test and treat over traditional prevention programs. First, administering antiretroviral therapy to infected patients as a prevention method fits perfectly within current healthcare infrastructure. It doesn't require public health officials to establish new schools or clinics -- test and treat can be carried out in the same treatment clinics that already exist. The problem? Test and treat is not as effective alone. "Data shows that different interventions together pack a powerful punch," said Venter. In fact, it is dangerous to rely on test and treat alone. Because antiretroviral therapy is a life-long treatment, patients often drop out, and test and treat only works if viral load stays below a certain threshold. Retention is the "Achilles heel" of test and treat, Venter said.

Case Study: TAPS

The concept of test and treat paired with other prevention programs is being tested in Venter's TAPS project which stands for "Treatment and prevention for female sex workers in South Africa." The straightforward program offers free HIV tests to sex workers in South Africa for HIV. If the test is positive, the patient will be offered antiretroviral therapy. If the test is negative, the patient will be offered PrEP. Venter said retention has not been a problem in TAPS -- at the time of his presentation at IAS 2015, TAPS had not lost a single patient to follow up. The reason? "When you treat people with humanity and respect, you don't have to try that hard," Venter said.