Background Few studies have assessed patients’ sexual behaviours during the period immediately following a new diagnosis of a curable sexually transmitted infection (STI).

Methods Data were analysed from a behavioural study nested within the Safe in the City trial, which evaluated a video-based STI/HIV prevention intervention in three urban STI clinics. We studied 450 patients who reported having received a new STI diagnosis, or STI treatment, 3 months earlier. Participants reported on whether they seriously considered, attempted and succeeded in adopting seven sex-related behaviours in the interval following the diagnostic visit. We used multivariable logistic regression to identify, among men, correlates of two behaviours related to immediately reducing reinfection risk and preventing further STI transmission: sexual abstinence until participants were adequately treated and abstinence until their partners were tested for STIs.

Results Most participants reported successfully abstaining from sex until they were adequately treated for their baseline infection (89%–90%) and from sex with potentially exposed partners until their partners were tested for HIV and other STIs (66%–70%). Among men who intended to be abstinent until they were adequately treated, those who did not discuss the risks with a partner who was possibly exposed were more likely not to be abstinent (OR, 3.7; 95% CI 1.5 to 9.0) than those who had this discussion. Similarly, among men who intended to abstain from sex with any potentially exposed partner until the partner was tested for HIV and other STIs, those who reported not discussing the risks of infecting each other with HIV/STIs were more likely to be sexually active during this period (OR, 3.5; 95% CI 1.6 to 8.1) than were those who reported this communication.

Conclusions Improved partner communication could facilitate an important role in the adoption of protective behaviours in the interval immediately after receiving a new STI diagnosis.

Trial registration number NCT00137670.