| Issue/Objective |
Malawi's oral PrEP programme has expanded rapidly since 2021, but national evidence on whether it is preventing HIV infections among people who report PrEP use is limited. We used routine HIV testing services (HTS) register data to estimate HIV incidence among people reporting PrEP use and to assess whether HTS data can provide surveillance signals to identify geographic priorities for national PrEP programming. |
| Methodology/Approach |
We conducted a cross-sectional analysis of digitized national HTS registers from November 2022 to October 2025, which include self-reported time since PrEP use at each encounter. Eligible encounters required a prior professional HIV-negative test, a current HIV test result, and recorded time since last PrEP use, with no linkage to an external PrEP database. Incident infections were defined as positive results at the current HIV test. Person-time was the inter-test interval, with seroconversions contributing half the interval under a midpoint assumption. PrEP timing patterns were classified as very recent use (≤28 days), recent use (29-90 days), use greater than 90 days prior, use before the last negative test, or same-day or uncertain ordering. We estimated HIV incidence per 100 person-years with exact Poisson 95% confidence intervals overall, by timing pattern, and by district among very recent PrEP users. |
| Results |
PrEP-reporting encounters (n=204,289) contributed 103,839 person-years with 1,104 incident diagnoses (1.06 per 100 person-years; 95% CI 1.00-1.13), compared with 1.25 per 100 person-years among encounters not reporting PrEP use. Incidence was lowest with very recent PrEP use (≤28 days: 0.60 per 100 person-years; 95% CI 0.51-0.70) and substantially higher with 29-90 days (1.67) and greater than 90 days (1.92) since last use. Among very recent users, incidence was notably higher in women than men (0.92 vs. 0.29 per 100 person-years). District-level incidence varied markedly, ranging from 0.45 in Blantyre and Mulanje to 1.23 in Mzimba North. |
| Discussion/Conclusion |
PrEP is reaching very high-risk individuals in Malawi, but incidence remains high when use is not recent, indicating critical gaps in adherence. Lower incidence with very recent use suggests partial protection, yet persistent high incidence underscores the need to strengthen adherence support and rapidly scale long-acting PrEP and complementary prevention strategies. |
| Presenters and Affiliations |
Gashaija Absolomon Centre for Impact, Innovation and Capacity building for Health Information Systems and Nutrition (CIIC-HIN), Kigali, Rwanda |
