Abstract
BACKGROUND: The rising prevalence of extramarital sexual networking has led to increasing susceptibility to HIV infection among married couples. This study aimed to determine the prevalence of extramarital sex among married individuals in Mbarara Regional Referral Hospital, the factors linked to it and its relationship with HIV. METHODS: Data were collected using an interviewer-administered questionnaire. Participants were clients seeking HIV testing at a tertiary hospital in southwestern Uganda between June and September 2025. All clients received standard pre- and post-test counselling. Data was analyzed using Stata version 17. RESULTS: The study included a sample of 384 participants, with an almost equal distribution across the genders (50.3% female; 49.7% male). The prevalence of extramarital sex was 58.1% (95% CI: 0.51-0.65) among men and 8.2% (95% CI: 0.05-0.13) in women. Among those who reported extramarital sex, the prevalence of HIV was 10.5% (95% CI: 0.07-0.16) and 5.1% (95% CI: 0.03-0.13) for men and women respectively. An equal number (8) of men and women who denied involvement in extramarital sex were also diagnosed with HIV. The results suggested no relationship between extramarital sex and HIV (OR 0.9, 95% CI: 0.38-1.90, p = 0.7). However, women were found to be at an increased risk of acquiring HIV (RR = 2.02, 95% CI: 0.91-4.47) compared to men. Multivariate logistic regression identified the following factors to be linked to extramarital sex: being male (aOR = 16.4, 95% CI: 9.13-29.41, p < 0.001), monogamous marriage status (aOR = 3.2, 95% CI: 1.51 - 6.93, p = 0.002), marital duration exceeding 19 years (aOR = 3.8, 95% CI: 1.92 - 7.56, p < 0.001), being Muslim (aOR = 2.4, 95% CI: 1.04 - 5.49, p = 0.04), alcohol consumption (aOR = 3.5, 95% CI: 2.14 - 5.58, p < 0.001), sexual dissatisfaction among females (aOR = 11.1, 95% CI: 3.82-15.14, p < 0.001) and sharing workplace (aOR = 7.6, 95% CI: 0.96-61.01, p = 0.05). Conversely, factors negatively linked to extramarital sex in this study included identifying as female (aOR = 0.7, 95% 0.03-0.14, p < 0.001), and having no formal education (aOR = 0.3, 95% CI: 0.09 - 0.63, p = 0.003). CONCLUSION: The study observed a high rate of extramarital sex in the study setting. This was a baseline study. Therefore, subsequent research is needed to identify the underlying reasons for seeking extramarital affairs in Southwestern Uganda.