The cost-effectiveness of Pre-Exposure Prophylaxis in HIV Prevention: Analysis from A Multicentre Intervention in Northern Nigeria

Abstract

Background: Pre-exposure prophylaxis (PrEP) is recommended for people at substantial risk of acquiring HIV to prevent new infections. The Nigeria PEPFAR program through USAID funded the implementation of PrEP for Key Population (KP) groups including Men Who Have Sex with Men (MSM), People who inject drugs (PWIDS), and Female sex Workers (FSW) in July 2020. We assessed the number of new infections averted and the financial resources saved because of this intervention. Methodology: HIV-negative clients from the key population community in North- East Nigeria eligible for PrEP were enrolled over a 7-month period (July 2020 – February 2021). Eligibility criteria used include being at substantial risk for HIV infection based on a screening test administered. The person-month was calculated by using the duration the participants were retained on PrEP. The incidence 15.4/100 person-years of HIV among MSM at high risk of HIV infection in the TRUST study conducted in Nigeria was used to calculate the expected positive cases if PrEP was not provided for those enrolled using the formula (15.4/100 * X) where X is number of person-years. We compared the expected positive to the actual positive seen among KPs while on PrEP within the study period. The cost-effectiveness of being on PrEP was calculated by multiplying the standard cost per HIV infection averted ($13, 267 per HIV infection averted) by the No of HIV averted. Results: We enrolled a total of 1,197 eligible HIV-negative KPs within the study period (189 were retained for seven months, 407 for four months, 585 for 3 months, and 18 for 1 month). A total of 4722 person-months (394 person-years) were accumulated over the period of the study. Using the incidence of 15.4/100 person-years, the expected positive cases if PrEP was not provided was 61 (15.4/100 *394). With the use PrEP, no client seroconverted to be HIV positive. This means that within the 7-month period, 61 HIV infections were averted. At the cost of $13,267 per HIV infection averted for PrEP, the project saved $809,287 for averting 61 HIV infections in seven months of using PrEP among HIV-negative KPs involved in high-risk behaviors. Conclusion: This study shows that PrEP is effective in averting new infections among key population groups. Placing high-risk groups such as KPs on PrEP is cost-effective due to the money saved from new infections averted. Increased funding for proven and innovative strategies on PrEP enrolment, retention, and adherence of eligible clients should be expanded for KPs.