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  • Blue Ocean l 17-01-25 00:00:00 l View : 1391

  • Science Magazine December 2016

    AIDS epidemic nears control

    in three African countries

    Massive new surveys show stunning progress

    By Jon Cohen


     Amidst the reams of statistics that pour out on every World AIDS Day on 1 December came one surpris­ing bit of good news this year. Three neighboring, cash-strapped countries in hard-hit southern Africa — Malawi, Zambia, and Zimbabwe — have had remarkable success against the virus, according to the most comprehensive study done to date.

     The new study, coordinated out of the Columbia University Mailman School of Public Health and led by epidemiologist Wafaa El-Sadr, collected massive amounts of on-the-ground data by visiting 80,000 randomly selected households in the three countries. The upshot: HIV-infected people in the region are getting treated and sticking with their drug regimen in numbers that have surprised and delighted experts. The survey found that up to two-thirds of HIV-infected people in the three countries have fully suppressed the virus, slashing the rate of new infections. (In the United States, the comparable figure is 30%.) “We’re getting very close to the number that shuts down epidemics,” says Deborah Birx, who heads the U.S. President’s Emergency Plan for AIDS Relief (PEPFAR) in Washington, D.C.

     Until now, the most authoritative estimates of new HIV infection rates, or incidence, and prevalence have come from the Joint United Nations Programme on HIV/AIDS (UNAIDS). Those are based on mathematical models that largely extrapolate from clinics and nonrandomized surveys. The UNAIDS estimates do not include the level of virus in each infected person, a key indication of how well interventions are working.

     The new population-based HIV impact assessments (PHIAs), which began in 2015 and are funded by PEPFAR, fill that gap. In addition to going door-to-door in cities, teams traveled to  the  remote countryside,  often pulling up to thatch-roofed homes and erecting popup tents in which nurses did blood draws. Social scientists also interviewed participants about their health and lifestyle. Blood was assessed on the spot for HIV and syphilis, with counseling and treatment referrals made for anyone in need. Then the teams took the vials back to cities to analyze viral levels. “We have to reach people we haven’t reached and know exactly where the crusade is failing,” El-Sadr said during a survey in Zimbabwe.

     The results, released in press releases and fact sheets, mostly confirm the UNAIDS esti­mates of HIV’s reach in the three countries— which each have a prevalence of more than 10% of the adult population. But they showed an annual rate of new infections in Zimbabwe and Zambia that was substantially lower than expected (see table, below). Peter Ghys, who directs strategic information and evalua­tion at UNAIDS in Geneva, Switzerland, says his team will incorporate the PHIA data in future modeling estimates.

     Across the region, the PHIA results sug­gest, the rate of new infections has fallen by half since 2003. Data on viral levels point to one factor: At least 86% of people in each country receiving antiretroviral treatment had “fully suppressed” HIV. This means they had such low levels of virus in their blood that the drugs not only are staving off AIDS, but making it highly unlikely that they will infect others. “We were amazed when we saw this,” El-Sadr says.

     The result helps assuage worries that many infected people in those countries are not sticking with their treatment. PEPFAR surveys of clinics had suggested that more than 20% of people who started treatment ended up dropping it. “We were misled at the program level about retention,” Birx says. The PHIA data’s high level of viral suppression suggests that instead, “people were moving from one clinic to another and it looked like they were lost to follow-up.”

     All three countries have received substan­tial international assistance for HIV/AIDS prevention and treatment: Since 2004, PEP­FAR has invested $4 billion, and the Global Fund to Fight AIDS, Tuberculosis and Ma­laria has provided $2 billion more. But fund­ing alone does not explain the gains against the virus, Birx says. “These programs and the people implementing them have done an extraordinary job of working with the community and the individual clients.”

     The new data have important implications for the global push to end HIV/AIDS epidemics by 2030. To achieve that, UNAIDS has set what is known as the 90-90-90 goal for 2020. UNAIDS modeling shows that epidemics will peter out if 90% of infected people know their HIV status, 90% of that group receives antiretrovirals, and 90% on treatment have undetectable viral levels. This translates to undetectable viral levels in 73% of all HIV-infected people in a population—including those who don’t know their status and have uncontrolled infections. The PHIA numbers suggest the goal is within reach: Malawi is already at 67.6%, Zimbabwe is at 60.4%, and Zambia is at 59.8%. The preliminary findings are “pretty doggone amazing,” Birx says. “This really shows why it is so important to get community-level survey data.”