To assess the pooled prevalence of self-reported sexually transmitted infections (STIs) and their associated factors among adults in South and Southeast Asia, using the Demographic and Health Survey data collected between 2015 and 2023.

A community-based cross-sectional study design was conducted using a multistage cluster sampling approach. Multilevel multivariable logistic regression analysis was employed to identify predictors of self-reported sexually transmitted infections (STIs). Model selection was guided by Akaike’s information criterion, and adjusted odds ratios (AORs) with 95% CIs were estimated to determine statistically significant associations.

South and Southeast Asia.

This analysis included a weighted sample of 791 019 adults aged 15–49 who reported ever having had sexual intercourse. The majority of the participants were female (n=6 87 880; 87%), and most were from Southeast Asia (n=7 00 539; 89%).

The pooled prevalence of self-reported STIs among adults in South and Southeast Asia was 12.94% (95% CI 7.73% to 18.14%). At the individual level, higher odds of reporting STIs were associated with being female (AOR 1.84; 95% CI1.68 to 2.02), having middle (AOR 1.11; 95% CI 1.04 to 1.19) or high wealth status (AOR 1.15; 95% CI 1.07 to 1.24]), being employed (AOR 1.14; 95% CI 1.07 to 1.22), having multiple sexual partners (AOR 2.79; 95% CI 2.22 to 3.52) and having undergone HIV testing (AOR 1.10; 95% CI: 1.02 to 1.20). Conversely, lower odds of self-reported STIs were observed among individuals aged 35–39 years (AOR 0.78; 95% CI 0.66 to 0.92), 40–44 years (AOR 0.68; 95% CI 0.58 to 0.82) and 45–49 years (AOR 0.61; 95% CI 0.52 to 0.73); those who had ever been in a union (AOR 0.71; 95% CI 0.62 to 0.83); individuals with higher education (AOR 0.84; 95% CI 0.76 to 0.93); and those with comprehensive HIV knowledge (AOR 0.82; 95% CI 0.77 to 0.87). At the community level, high illiteracy rates (AOR 1.25; 95% CI 1.15 to 1.35) and high media non-exposure (AOR 1.11; 95% CI 1.02 to 1.20) were positively associated with STIs, while rural residence (AOR 0.81; 95% CI 0.74 to 0.89) and living in Southeast Asia (AOR: 0.47; 95% CI 0.42 to 0.53) were linked to lower odds of self-reported STIs.

A substantial prevalence of self-reported STIs was observed among adults in South and Southeast Asia. Both individual- and community-level factors influence STI risk. The individual-level determinants include socio-demographic characteristics, sexual behaviours, HIV-related knowledge and testing history, while community-level factors reflect disparities in geographic location, educational attainment and media exposure.