Environmental Extremes and Sexual Health: A Study of Floods and STIs in India

Background: Sexually transmitted infections (STIs) remain a significant global public health burden. According to the World Health Organization (WHO), approximately one million new STI cases occur daily worldwide. Previous studies have shown that exposure to extreme environmental conditions is positively associated with STI prevalence, but the specific effect of floods remains underexplored. Aim: This study aims to examine the association between flood exposure and STI prevalence among men. Data and Methods: This study utilized the men recode dataset from the National Family Health Survey (NFHS-5) and district-level flood data from the annual report of the Central Water Commission, Ministry of Jal Shakti, Government of India. Statistical analyses included chi-square tests to assess STI prevalence across covariates, and binary logistic regression to estimate the risk of STIs associated with flood exposure. Results: Findings indicate that men exposed to floods have a 15% higher risk of acquiring STIs (AOR: 1.15; 95% CI: 1.04–1.27). Risky sexual behaviours such as having more than one intimate partner (AOR: 1.74; 95% CI: 1.47–2.06) and engagement in paid sex (AOR: 2.56; 95% CI: 2.24–2.92) further increase STI risk. A higher prevalence of STIs was observed among unmarried men aged 15–24 years exposed to floods (13.94%, p < 0.001; 13.6%, p < 0.001, respectively) as compared to their counterparts. Population attributable fraction analysis suggests that over 1.7 million STI cases could be prevented with effective mitigation measures. Conclusion: Flood exposure increases the risk of STIs by disrupting daily activities and healthcare services. Timely implementation of appropriate mitigation strategies during and immediately after floods is essential to reduce the STI prevalence.