Risk factors associated with sexually transmitted infections in Nigeria: a systematic review

Sexually transmitted infections (STIs) pose a major public health challenge globally, with Nigeria experiencing a significant burden. Despite on-going sexual health interventions, the determinants of STI risk across diverse Nigerian populations remain insufficiently understood. This systematic review synthesizes current evidence to inform policy and intervention strategies. A comprehensive search of PubMed, Web of Science, EMBASE, and AJOL used Boolean operators and STI-related keywords. Eligible peer-reviewed studies, conducted in Nigeria between 2014 and 2023, examined STI risk factors and used qualitative, quantitative, or mixed-methods designs. Studies were screened using predefined criteria, appraised with JBI tools, and synthesized through narrative and thematic approaches. Twenty-three studies met the inclusion criteria and highlighted multiple influences on STI risk in Nigeria. Socioeconomic conditions, including education and employment, shaped access to contraceptives and sexual health services. Cultural expectations and gender norms affected attitudes and behaviours related to protection. Structural challenges such as condom unavailability and limited sexual health information were more pronounced in rural settings. Interpersonal dynamics, including partner communication and decision-making capacity, influenced protective behaviour, while substance use and low risk perception increased STI vulnerability. STI risk in Nigeria is shaped by interconnected socioeconomic, cultural, structural, interpersonal, and behavioural factors. Strengthening sexual health education, addressing gender disparities, improving contraceptive access, and integrating mental health support are critical for reducing STI burden. The review is registered with PROSPERO (CRD42024551254).