A Randomized Controlled Trial of a Texting Intervention to Maintain Sexual Risk Reduction with Clients Among Female Sex Workers in Tijuana and Ciudad Juarez, Mexico.

: Mobile phone technology may help sustain reductions in HIV/STI transmission risk behaviors among female sex workers (FSWs). We examined the efficacy of a text messaging intervention designed to maintain behavioral improvements in safer sex practices among 602 FSWs in Tijuana and Ciudad Juarez, Mexico. We hypothesized that FSWs who received brief risk reduction counseling and theory-based safer sex maintenance text messages over a 24-month period would have fewer incident HIV/STIs and report greater maintenance of safer sex practices compared to FSWs who received counseling and texts on maintaining general health. Theory-based texts did not change the odds of becoming infected with HIV/STIs in either study site. However, they did lead to significant, sustained protected sex in Tijuana. Theory-based text messaging interventions may help sustain reductions in sexual risk behavior among FSWs.Trial Registration Clinical Trials.gov. Identifier: NCT02447484.