HIV Prevention Efforts and Incidence of HIV in Uganda

Abstract

Background: To assess the effect of a combination strategy for prevention of human immunodeficiency virus (HIV) on the incidence of HIV infection, we analyzed the association between the incidence of HIV and the scale-up of antiretroviral therapy (ART) and medical male circumcision in Rakai, Uganda. Changes in population-level viral-load suppression and sexual behaviors were also examined.

Methods: Between 1999 and 2016, data were collected from 30 communities with the use of 12 surveys in the Rakai Community Cohort Study, an open, population-based cohort of persons 15 to 49 years of age. We assessed trends in the incidence of HIV on the basis of observed seroconversion data, participant-reported use of ART, participant-reported male circumcision, viral-load suppression, and sexual behaviors.

Results: In total, 33,937 study participants contributed 103,011 person-visits. A total of 17,870 persons who were initially HIV-negative were followed for 94,427 person-years; among these persons, 931 seroconversions were observed. ART was introduced in 2004, and by 2016, ART coverage was 69% (72% among women vs. 61% among men, P<0.001). HIV viral-load suppression among all HIV-positive persons increased from 42% in 2009 to 75% by 2016 (P<0.001). Male circumcision coverage increased from 15% in 1999 to 59% by 2016 (P<0.001). The percentage of adolescents 15 to 19 years of age who reported never having initiated sex (i.e., delayed sexual debut) increased from 30% in 1999 to 55% in 2016 (P<0.001). By 2016, the mean incidence of HIV infection had declined by 42% relative to the period before 2006 (i.e., before the scale-up of the combination strategy for HIV prevention) - from 1.17 cases per 100 person-years to 0.66 cases per 100 person-years (adjusted incidence rate ratio, 0.58; 95% confidence interval [CI], 0.45 to 0.76); declines were greater among men (adjusted incidence rate ratio, 0.46; 95% CI, 0.29 to 0.73) than among women (adjusted incidence rate ratio, 0.68; 95% CI, 0.50 to 0.94).

Conclusions: In this longitudinal study, the incidence of HIV infection declined significantly with the scale-up of a combination strategy for HIV prevention, which provides empirical evidence that interventions for HIV prevention can have a population-level effect. However, additional efforts are needed to overcome disparities according to sex and to achieve greater reductions in the incidence of HIV infection. (Funded by the National Institute of Allergy and Infectious Diseases and others.).

Figure 1.. Sexual Behaviors in the Rakai Community Cohort Study, 1999-2016.

Figure shows proportion of HIV-negative men and women by age-group and overall ages reporting the following sexual behaviors A-B) never initiating sex (i.e. delayed sexual debut), C-D) multiple sexual partnerships among sexually active persons, and E-F) consistent condom use among those reporting casual (i.e. non-marital) sexual partnerships. The most substantial changes in sexual behaviors occurred among adolescent men and women aged 15-19 years reporting never initiating sex and adolescent men reporting multiple partnerships.

Figure 2.. Scale-up of antiretroviral therapy, viral suppression in HIV-positive participants and male circumcision, 1999-2016.

2A shows scale-up of ART coverage measured by selfreport in men, women and all HIV-positive RCCS participants beginning in 2006. Figure 2B show the proportion of all HIV-positive persons by gender and overall virologically suppressed (<1000 HIV copies/ml) in 2009 and 2016. 2C shows scale-up of MC coverage in men irrespective of religion by HIV status and overall beginning in 2004. 2D shows community-level MC coverage vs. community-level ART coverage for all 30 communities at each survey during CHP scale-up. A smoothing-spline was fit to the smooth curve to assess trend. Scale-up of interventions occurred simultaneously and increased significantly in all communities.

Figure 3.. HIV incidence and prevalence trends in the Rakai Community Cohort Study, 1996-2016.

Trends in HIV incidence and prevalence over the analysis period among all initially HIV-negative men and women in the incidence cohort (3A), women only (3B), men only (3C), and in men by circumcision status (3D). HIV incidence is only shown for circumcised men ginning in 2007 after the WHO recommendation for MC for HIV-negative men for HIV prevention. HIV prevalence is shown in red and HIV incidence and 95% CI for each visit interval are shown in blue (green for circumcised men). The ART and MC coverage plots are also included to show the temporal association between scale-up of CHP and declines in HIV incidence.