Sexually transmitted infections and sexual behaviour of deploying shipboard US military personnel: a cross-sectional analysis

Objectives Sexually transmitted infection (STI) prevalence and risk behaviour may differ at different phases of deployment. We examined STI prevalence and sexual behaviour in the predeployment time period (12 months prior) among recently deployed shipboard US Navy and Marine Corps military personnel. Methods Data were collected from 1938 male and 515 female service members through an anonymous, self-completed survey assessing sexual behaviours and STI acquisition characteristics in the past 12 months. Cross-sectional sex-stratified descriptive statistics are reported. Results Overall, 67% (n=1262/1896) reported last sex with a military beneficiary (spouse, n=931, non-spouse service member, n=331). Among those with a sexual partner outside their primary partnership, 24% (n=90/373) reported using a condom the last time they had sex and 30% (n=72/243) reported their outside partner was a service member. In total, 90% (n=210/233) reported acquiring their most recent STI in the USA (88%, n=126/143 among those reporting >= 1 deployments and an STI >= 1 year ago) and a significantly higher proportion (p<0.01) of women than men acquired the STI from their regular partner (54% vs 21%) and/or a service member (50% vs 26%). Conclusions Findings suggest a complex sexual network among service members and military beneficiaries. Findings may extend to other mobile civilian and military populations. Data suggest most STI transmission within the shipboard community may occur in local versus foreign ports but analyses from later time points in deployment are needed. These data may inform more effective STI prevention interventions.