Missed HIV Prevention Opportunities: Multilevel Determinants of PrEP Uptake Among STI Clinic Attendees in Zambia

Abstract

Background: Individuals with sexually transmitted infections (STIs) are at elevated risk of HIV acquisition, yet uptake of HIV pre-exposure prophylaxis (PrEP) in STI service settings remains suboptimal, especially in high-burden countries. This study evaluated PrEP uptake and determinants among STI clinic attendees in Lusaka and Livingstone, Zambia.

Methods: A retrospective observational study of 720 laboratory-confirmed, HIV-negative STI patients seen from January to December 2020 was conducted. Data were extracted from STI clinic records and PrEP files. Further, a cross-sectional survey of 45 healthcare workers (HCWs) working in STI delivery points was conducted to assess PrEP- related knowledge and training. Logistic regression was employed to identify factors associated with PrEP uptake, reported as adjusted odds ratios (AORs).

Results: PrEP was initiated by 34% of STI clinic attendees. Uptake was higher among those with multiple sexual partners (AOR 2.24, 95% CI 1.23–4.07), self-perceived HIV risk (AOR 2.48, 95% CI 1.47–4.19), prior PrEP use (AOR 2.09, 95% CI 1.22–3.58), and key population status (AOR 2.32, 95% CI 1.31–4.12). Lower uptake was observed among those formally married (AOR 0.25, 95% CI 0.13–0.45), with negative PrEP attitudes (AOR 0.18, 95% CI 0.10–0.33), or alcohol use (AOR 0.16, 95% CI 0.09–0.27). Only 38% of HCWs were formally trained in PrEP.

Conclusion: PrEP uptake in Zambian STI clinics is shaped by behavioural risk, perceived vulnerability, social context, and provider capacity. Optimizing HIV prevention requires integrating PrEP delivery in STI clinics with targeted interventions to address attitudinal barriers, and expanded HCW training.