The hypothesis is that a behavioral intervention tool adapted for the US military population will be acceptable and associated with a decrease in incident sexually transmitted infection (STI)/HIV rates and high-risk sexual behaviors, and increased self-reported condom use compared to the standard of care at the Joint Base Lewis-McChord (JBLM) Preventive Medicine clinic and the Fort Bragg Department of Public Health (part of Womack Army Medical Center).

This is the Execution Phase which will be conducted as a multi-site randomized controlled trial. A previous Formative Phase study was conducted under a separate protocol which has been completed with preliminary data indicating positive outcomes. Participants in both arms will meet the same inclusion/exclusion criteria and will be randomized into the intervention and control arms at a ratio of 1:1.

The intervention arm will receive the KISS (Knocking out Infections through Safer sex and Screening) intervention program in addition to standard STI prevention counselling routinely provided by military medical treatment facilities. The control arm will receive only standard STI prevention counselling. Both arms will receive follow-up educational messages via short message service (SMS)/text messaging monthly for 10 months, and have follow-up study visits at 6 months and 12 months.

The KISS intervention is a 2-hour, small group (6-12 individuals) class-based interactive, educational session based on Social Cognitive Theory and the Theory of Gender and Power. The intervention is an adaptation of the HORIZONS intervention, which has shown efficacy are reducing sexual risk behavior and incident STIs among adolescents in the USA. HORIZONS has been reviewed by the U.S. Centers for Disease Control (CDC) Prevention Synthesis Research team and designated a CDC top-tier (Tier I) evidence-based intervention (EBI).

To enroll in the study, participants must be categorized as "high risk" as determined by a positive test for an STI within the previous 180 days or has had STI screening during this time frame (specifically gonorrhea (GC), chlamydia (CT), M. genitalium, syphilis and/or HIV).

Study subjects will be recruited from Madigan Army Medical Center (Madigan) Preventive Medicine Clinic and the Womack Army Medical Center (Womack) Preventive Medicine Clinic in Ft. Bragg, North Carolina (NC). In addition, promotional flyers for recruitment will be placed in public areas on both bases, and will be promoted through approved social media channels. Subjects may also refer up to 5 friends or colleagues for screening.

Participants enrolled in the intervention arm will complete a total of four visits and those in the control arm will complete a total of three visits. Over the course of the study, participants in both groups will be asked to provide biological specimens and complete knowledge/behavioral surveys three times (at baseline, 6 and at 12 months). Those in the intervention group will also attend the KISS EBI (Evidence Based Intervention) program. Both arms will receive monthly (months 2-11) follow up text messages, but the content will defer between the two arms. Those in the intervention arm, will receive SMS/text messages targeting prevention maintenance interventions (PMI) messages reiterating information received during the EBI session. Those in the control arm, will receive SMS/text messages that will contain general health information.

Inclusion Criteria:

1. Age 18 - 30 years
2. Army active duty or Army medical beneficiary
3. Eligible to receive care at a military healthcare clinic for at least 12 months from enrollment
4. HIV negative
5. Not scheduled for military deployment or transfer within 3 months of enrolment
6. Not pregnant, regardless of marital status
7. Not trying to become pregnant or impregnate a partner, regardless of marital status
8. Be classified as "high risk" either through a positive STI diagnosis in the last 180 days or has had STI screening during this timeframe.
9. Self reports vaginal, oral, and/or anal sexual contact in the last 30 days.

Exclusion Criteria:

1. Under 18 or over 30 years of age
2. Not Army active duty or Army medical beneficiary
3. Not eligible to receive care at a military healthcare clinic for study duration (next 12 months)
4. HIV positive
5. Military deployment or transfer scheduled within 3 months of enrollment
6. Are pregnant, regardless of marital status
7. Are trying to become pregnant or impregnate someone, regardless of marital status
8. Has not had a positive STI diagnosis or STI screening within the last 180 days
9. Does not self-report vaginal, anal, and/or oral sexual contact in the last 30 days

Requests for data sharing may be considered on a case-by-case basis