Modeling the impact of different PrEP targeting strategies combined with a clinic-based HIV-1 nucleic acid testing intervention in Kenya

Background: Up to 69% of adults who acquire HIV in Kenya seek care for acute retroviral symptoms, providing an important opportunity for early diagnosis and HIV care engagement. The Tambua Mapema Plus (TMP) trial tested a combined HIV-1 nucleic acid testing, linkage, treatment, and partner notification intervention for adults with symptoms of acute HIV infection presenting to health facilities in coastal Kenya. We estimated the potential impact on the Kenyan HIV epidemic of providing PrEP to individuals testing negative in TMP, if scaled up. Methods: We developed an agent-based simulation of HIV-1 transmission using TMP data and current Kenyan statistics. PrEP interventions were layered onto a model of TMP as standard of care, to estimate additional potential population-level impact of enrolling HIV-negative individuals identified through TMP on PrEP over 10 years. Four scenarios were modeled: PrEP for uninfected individuals in disclosed serodiscordant couples; PrEP for individuals with concurrent partnerships; PrEP for all uninfected individuals identified through TMP; and PrEP integrated into the enhanced partner services component of TMP. Findings: Providing PrEP to both individuals with concurrent partnerships and uninfected partners identified through enhanced partner services reduced new HIV infections and was efficient based on numbers needed to treat (NNT). The mean percent of infections averted was 2.79 (95%SI:−10.83, 15.24) and 4.62 (95%SI:−9.5, 16.82) when PrEP uptake was 50% and 100%, respectively, and median NNT was 22.54 (95%SI:not defined, 6.45) and 27.55 (95%SI:not defined, 11.0), respectively. Providing PrEP for all uninfected individuals identified through TMP averted up to 12.68% (95%SI:0.17, 25.19) of new infections but was not efficient based on the NNT: 200.24 (95%SI:523.81, 123.23). Conclusions: Providing PrEP to individuals testing negative for HIV-1 nucleic acid after presenting to a health facility with symptoms compatible with acute HIV adds value to the TMP intervention, provided PrEP is targeted effectively and efficiently. Funding: National Institutes of Health, Sub-Saharan African Network for TB/HIV Research Excellence