December 11, 2017HIV/AIDS
Combination HIV Prevention Reduces New Infections by 42%% In Ugandan District NIH-supported study provides evidence for implementing approach broadly.
According to a study published in the New England Journal of Medicine (29 November 2017), a combination of proven HIV prevention measures across communities can substantially reduce new HIV infections in a population. The study found that HIV incidence dropped by 42% among nearly 18,000 people in Rakai District, Uganda, during a seven-year period in which the rates of HIV treatment and voluntary medical male circumcision increased significantly.
The HIV prevention strategy whose impact was observed in the study is based on earlier findings by the National Institutes of Health and others demonstrating the protective effect of voluntary medical male circumcision for HIV-uninfected men, and of HIV-suppressing antiretroviral therapy (ART), for halting sexual transmission of the virus to uninfected partners. The strategy is also based on studies showing that changes in sexual behavior, such as having only one sexual partner, can help prevent HIV infection.
The study involved nearly 34,000 people ages 15 to 49 years residing in 30 communities that participate in the Rakai Community Cohort Study (RCCS) conducted by the Rakai Health Sciences Program in Uganda. This program promoted HIV testing, ART and voluntary medical male circumcision to study participants. Every one or two years from April 1999 until September 2016, participants were tested for HIV and surveyed about their sexual behavior, use of HIV treatment, and male circumcision status. Results showed that the proportion of study participants living with HIV who reported taking ART climbed from zero in 2003 to 69% in 2016. The proportion of male study participants who were voluntarily circumcised grew from 15% in 1999 to 59% in 2016. While levels of condom use with casual partners and the proportion of people reporting multiple sexual partners remained largely unchanged, the proportion of adolescents ages 15 to 19 who reported never having sex rose from 30% in 1999 to 55% in 2016.
As an apparent consequence of these increases, particularly in ART use and voluntary male circumcision, the annual number of new HIV infections in the cohort fell from 1.17 per 100 person-years in 2009 to 0.66 per 100 person-years in 2016, a 42% decrease. Person-years are the sum of the number of years that each cohort member participated in the study. The researchers calculated the annual number of new HIV infections using data from nearly 18,000 of the almost 34,000 total participants. In addition, the proportion of cohort members living with HIV whose treatment suppressed the virus increased from 42% in 2009 to 75% in 2016, showing the feasibility of meeting the goal of the UNAIDS 90-90-90 initiative to achieve 73% viral suppression.
According to the authors, these findings are extremely encouraging and suggest that with sustained commitment to increase the number of people who use combination HIV prevention, it may be possible to achieve epidemic control and eventual elimination of HIV.
HIV incidence dropped the most among circumcised men (57%), likely because both their own circumcision and ART taken by their female sexual partners living with HIV protected these men from the virus. HIV incidence declined by 54% among all men but by only 32% among all women. According to the authors, this difference probably occurred because a greater percentage of women living with HIV than men living with HIV took ART, and because nearly two-thirds of men chose the extra preventive benefit of circumcision. The authors also suggest addressing this gender imbalance by influencing more men living with HIV to take ART and by giving HIV-uninfected women HIV prevention tools that they can control unilaterally, such as pre-exposure prophylaxis (PrEP). The authors anticipate that the RCCS will add PrEP to its combination HIV prevention package as the study continues.
The Rakai Health Sciences Program is an independent research organization whose collaborators include the Uganda Virus Research Institute of the Ministry of Health in Kampala, the NIAID Division of Intramural Research-supported International Center for Excellence in Research in Rakai, the U.S. Centers for Disease Control and Prevention partnership with Uganda (CDC-Uganda), Makerere University and the Johns Hopkins University Bloomberg School of Public Health.