Date Published: October 24, 2018
Publisher: Public Library of Science
Author(s): Sikhulile Moyo, Simani Gaseitsiwe, Terence Mohammed, Molly Pretorius Holme, Rui Wang, Kenanao Peggy Kotokwe, Corretah Boleo, Lucy Mupfumi, Etienne Kadima Yankinda, Unoda Chakalisa, Erik van Widenfelt, Tendani Gaolathe, Mompati O. Mmalane, Scott Dryden-Peterson, Madisa Mine, Refeletswe Lebelonyane, Kara Bennett, Jean Leidner, Kathleen E. Wirth, Eric Tchetgen Tchetgen, Kathleen Powis, Janet Moore, William A. Clarke, Shahin Lockman, Joseph M. Makhema, Max Essex, Vlad Novitsky, Alana T. Brennan.
Botswana is close to reaching the UNAIDS “90-90-90” HIV testing, antiretroviral treatment (ART), and viral suppression goals. We sought to determine HIV incidence in this setting with both high HIV prevalence and high ART coverage.
We used a cross-sectional approach to assessing HIV incidence. A random, population-based sample of adults age 16–64 years was enrolled in 30 rural and peri-urban communities as part of the Botswana Combination Prevention Project (BCPP), from October 2013 –November 2015. Data and samples from the baseline household survey were used to estimate cross-sectional HIV incidence, following an algorithm that combined Limiting-Antigen Avidity Assay (LAg-Avidity EIA), ART status (documented or by testing ARV drugs in plasma) and HIV-1 RNA load. The LAg-Avidity EIA cut-off normalized optical density (ODn) was set at 1.5. The HIV-1 RNA cut-off was set at 400 copies/mL. For estimation purposes, the Mean Duration of Recent Infection was 130 days and the False Recent Rate (FRR) was evaluated at values of either 0 or 0.39%.
Among 12,610 individuals participating in the baseline household survey, HIV status was available for 12,570 participants and 3,596 of them were HIV positive. LAg-Avidity EIA data was generated for 3,581 (99.6%) of HIV-positive participants. Of 326 participants with ODn ≤1.5, 278 individuals were receiving ART verified through documentation and were considered to represent longstanding HIV infections. Among the remaining 48 participants who reported no use of ART, 14 had an HIV-1 RNA load ≤400 copies/mL (including 3 participants with ARVs in plasma) and were excluded, as potential elite/viremic controllers or undisclosed ART. Thus, 34 LAg-Avidity-EIA-recent, ARV-naïve individuals with detectable HIV-1 RNA (>400 copies/mL) were classified as individuals with recent HIV infections. The annualized HIV incidence among 16–64 year old adults was estimated at 1.06% (95% CI 0.68–1.45%) with zero FRR, and at 0.64% (95% CI 0.24–1.04%) using a previously defined FRR of 0.39%. Within a subset of younger individuals 16–49 years old, the annualized HIV incidence was estimated at 1.29% (95% CI 0.82–1.77%) with zero FRR, and at 0.90% (95% CI 0.42–1.38%) with FRR set to 0.39%.
Using a cross-sectional estimate of HIV incidence from 2013–2015, we found that at the time of near achievement of the UNAIDS 90-90-90 targets, ~1% of adults (age 16–64 years) in Botswana’s rural and peri-urban communities became HIV infected annually.
Botswana has been hard hit by the HIV-epidemic, with the third highest HIV prevalence worldwide among adults age 15–49, after Lesotho and Swaziland . Botswana appears to be approaching the UNAIDS “90-90-90” HIV testing, treatment, and viral suppression targets . These high levels of coverage have led to significant reductions in HIV-related mortality [1, 3–5]. In June 2016 Botswana adopted the World Health Organization (WHO) recommendation to provide Universal Test and Treat (UTT) . The success of UTT could be measured by reduction in HIV incidence [7–25]. Monitoring of HIV incidence is a critical tool for assessment and evaluation the impact of HIV prevention and treatment programs.
A total of 3,596 (29%) individuals from 30 communities in Botswana were HIV positive among 12,570 adults 16–64 years old with definitive HIV status during the baseline household survey of the BCPP from 2013 to 2105 . Table 1 presents basic socio-demographic and clinical characteristics of individuals participating in the baseline household survey. The median (IQR) age was 40 (33–48) years. The majority of participants were females (73%). Among HIV-positive participants, 3,581 (99.6%) were tested by the LAg-Avidity EIA.
HIV incidence in a population-based sample of adults 16–64 years old residing in 30 communities across Botswana was estimated at about 1% from cross-sectional sampling that occurred in 2013–2015. Estimated HIV incidence was slightly higher (0.90–1.29%, depending on the FRR) in a subset of younger 16–49-year-old adults. Results of our study corroborate the recent UNAIDS estimates of HIV incidence in Botswana (0.93%) , and suggest a declining trend from previously estimated HIV incidence among 15–49 year old adults in Botswana (3.5% in 2000, 2.4% in 2007 and 1.7% in 2008 ). Our results support the observation that new HIV infections across sub-Saharan Africa continue to decline, although HIV incidence in Botswana remains unacceptably high .
In summary, using cross-sectional sampling and MAA based on LAg-Avidity EIA, ART status (either documented or by testing ARV drugs in plasma) and HIV-1 RNA measurements, we estimated the HIV incidence in 30 rural and peri-urban Botswana communities in 2013–2015 at about 1%. A higher proportion of recent infections were among participants less than 30 years of age. A reduction from this relatively high estimated HIV incidence may take several years to be realized despite the impact of widespread ART and other on-going interventions. Targeted interventions are required to reach individuals who have not yet sought HIV testing or treatment services.