INTEGRATION OF STI PREVENTION INTERVENTIONS WITHIN PrEP SERVICE DELIVERY: IMPACT ON STI RATES AND ANTIBIOTIC RESISTANCE

Abstract

The integration of sexually transmitted infection (STI) prevention interventions within pre-exposure prophylaxis (PrEP) service delivery represents a transformative advancement in contemporary sexual health and HIV prevention frameworks. This systematic review aims to evaluate the impact of integrated PrEP–STI services on infection rates, behavioral outcomes, and antimicrobial resistance, offering a comprehensive understanding of how unified care models influence global sexual health outcomes. Following the PRISMA 2020 guidelines, a total of 104 studies published between 2010 and 2021 were systematically reviewed across databases including PubMed, Scopus, Web of Science, CINAHL, and Embase, complemented by gray literature from WHO, UNAIDS, and CDC repositories. The included studies encompassed quantitative (n=68), qualitative (n=22), and mixed-methods (n=14) designs, spanning North America, Europe, sub-Saharan Africa, Latin America, and the Asia-Pacific. Key outcomes were synthesized around clinical effectiveness, behavioral dynamics, digital innovation, and antibiotic stewardship within integrated delivery frameworks. Findings indicate that the integration of STI prevention within PrEP services enhances early detection, treatment coverage, and patient engagement, leading to a 25–40% reduction in bacterial STI prevalence and 20–35% improvement in PrEP adherence and retention. While some studies reported an initial rise in STI case detection, these increases were largely attributable to intensified surveillance rather than genuine incidence escalation. Behavioral adaptations, such as reduced condom use or increased partner concurrency, were context-dependent and mitigated by motivational interviewing and counseling interventions embedded within integrated care. The incorporation of Doxycycline post-exposure prophylaxis (Doxy-PEP) further strengthened bacterial STI control, demonstrating up to 70–85% reductions in chlamydia and syphilis incidence, although necessitating ongoing antibiotic stewardship to curb resistance. Digital health tools and decentralized service models—such as telemedicine, mobile outreach, and peer-led interventions—emerged as critical enablers of accessibility, particularly in stigmatized or geographically marginalized communities. Integration reduced structural barriers, shortened treatment delays, and improved care satisfaction by consolidating services into a single, patient-centered continuum. However, significant limitations persist: research remains concentrated in high-income countries, with only 22% of studies conducted in low- and middle-income countries (LMICs), and most designs remain observational rather than randomized.