By Martha Henry
The end of AIDS as a public health threat may not come from an effective vaccine, as many had hoped for decades, but from a collaborative effort across nations to prevent new HIV infections. The epidemic that spread mainly through sexual connections may be subdued not from a single breakthrough, but through long-term transnational collaborations.
According to the World Health Organization (WHO), since the beginning of the epidemic, 78 million people have been infected with HIV. About 39 million of those have died from AIDS-related causes. Today, 36 million people are living with HIV. Sub-Saharan Africa remains the area most severely affected, accounting for over 70% of people living with HIV worldwide.
In 1981, what would later be named AIDS was first mentioned in the medical literature as a strange illness killing gay men in Los Angeles. By the late 1990s, the epidemic was devastating Africa. “We are threatened with extinction,” said President Festus Mogae of Botswana at an AIDS conference in Durban in 2000. “People are dying in chillingly high numbers.” That year, Botswana had the highest rate of HIV in the world—a staggering 35% of adults were infected.
A lot has changed since then. We now know how to treat HIV effectively with antiretroviral treatment (ART). Drug costs have dropped dramatically. Botswana established a national ART program in 2001. “The Botswana MASA program is the best in sub-Saharan Africa from the standpoint that it gets the largest fraction of individuals who need ART on ART, keeping them on treatment and virally suppressed,” said Dr. Max Essex, Chair of the Harvard AIDS Initiative (HAI) and the Botswana Harvard AIDS Institute Partnership (BHP). Essex has worked in Botswana since 1996.
Though great strides have been made in HIV treatment, the rate of new infections remains high. About two million people worldwide became infected last year, including an estimated 15,000 in Botswana.
BCPP: What it is and why it might work
The Botswana Combination Prevention Project (BCPP) is designed to evaluate whether a combination of proven HIV-prevention measures introduced into a community can significantly reduce HIV incidence—the number of new infections over time. In other words, by rapidly implementing what’s been scientifically shown to work, the BCPP hopes to dramatically decrease new HIV infections throughout a village. If the BCPP strategy works and is implemented on a large scale, the AIDS epidemic, with fewer and fewer new infections to fuel it, will burn itself out over time.
Modeling studies have suggested that a rapid scale-up of several evidence-based HIV prevention interventions may significantly reduce population-level HIV incidence. But models are not the real world.
“The BCPP is a way to determine whether treatment as prevention can work at the population level in southern Africa,” said Essex. The best-case scenario is “that we demonstrate that transmission can be effectively stopped, and thus that the epidemic will no longer be an epidemic in 20 years.”
“We strongly believe that with this project we have the chance to make history in the fight against AIDS,” said Michelle Gavin, the U.S. Ambassador to Botswana at the time of the November 2013 launch of the project in Gaborone, the capital of Botswana. “If this combination prevention strategy is shown to be effective and affordable, Botswana will be a global leader in providing scientific evidence needed to turn the tide on this epidemic.”
Ambitious in scope, the BCPP will track the number of new HIV infections in 16–64 year olds in 30 villages in Botswana over a three-year period.
The study format is a pair-matched community randomized trial, meaning that the 30 study communities are matched, based on similarities, into 15 pairs. In each pair, one village is randomly assigned to receive the combination prevention package and the other village receives the standard of care, as well as enhancements to its clinics, labs, and data management systems.
A Baseline Household Survey (BHS) of approximately 20% of randomly selected households is conducted in all 30 villages. From those households, an HIV incidence cohort of HIV-negative individuals is established. After the baseline survey is completed, the package of combination prevention interventions is rolled out in one of the villages in each pair. The villages that don’t receive the combination prevention interventions act as a control, but receive extra support in the way of HIV testing and referral for the survey participants. Residents of non-intervention communities can access free ART in the government treatment program.
The combination-prevention package includes:
- Rapid scale-up of HIV testing and counseling services
- Rapid scale-up of ART for adults eligible under government guidelines
- Rapid scale-up of ART for adults with high viral load who otherwise don’t qualify for treatment under government guidelines
- Beginning in 2016, rapid scale-up of ART for all HIV-infected individuals
- Rapid scale-up of Voluntary Male Circumcision
- Rapid scale-up of Prevention of Mother to-Child-Transmission services
The people in the HIV incidence cohort will be retested annually. At the end of the study, researchers will compare the number of new HIV infections in villages that received the combination prevention package with the villages that did not. The hypothesis is that new HIV infections will be significantly lower in the villages that received the package of interventions.
Who’s Doing What?
The BCPP is a joint effort of the Botswana Ministry of Health, the Harvard T.H. Chan School of Public Health AIDS Initiative (HAI), the Botswana Harvard AIDS Institute Partnership (BHP), and the U.S. Centers for Disease Control and Prevention (CDC).
The Ministry of Health and the CDC lead the Intervention Protocol, rapidly rolling out the combination prevention package. The Harvard team leads the Evaluation Protocol, conducting a baseline survey before the interventions are rolled out, then returning at 12, 24, and 36 months to evaluate the impact of the interventions in the participating communities. Funding for the BCPP is provided by the U.S. State Department’s Office of the Global AIDS Coordinator (OGAC) through the CDC. Results from the BCPP are expected in 2018.
Title photo by Dominic Chavez. BCPP field team members and villagers in Shakawe