The impact of opioid agonist treatment on the incidence of bacterial sexually transmitted infection notifications among people with a history of opioid dependence in New South Wales, Australia: A retrospective data linkage study.

Abstract

Opioid dependence is a risk factor for bacterial sexually transmitted infections (STIs). The role of STI screening in opioid agonist treatment (OAT) services has not been evaluated. We conducted a retrospective cohort study of all OAT recipients in New South Wales, Australia between 2001 and 2022 (N = 51,549), using linked administrative data. The main outcome was notification for chlamydia, gonorrhoea or infectious syphilis. Negative binomial regression models with generalised estimating equations were used to test whether STI notification rate was higher during periods on OAT. There were 2099 STI notifications among 1635 individuals (3.2 % of the cohort), equivalent to 4.30 (95 % confidence interval [CI]: 4.29-4.31) per 1000 person-years. There were more notifications for chlamydia (2.86 per 1000 person-years; 2.85-2.86), than gonorrhoea (1.30; 1.30-1.31) and syphilis (0.14; 0.14-0.14). Notifications increased over the study period and females experienced higher incidence than males (rate ratio: 1.69, 95 % CI: 1.55-1.84) Compared to periods off OAT, the incidence rate of STI notifications was elevated during the first 28 days of OAT (adjusted incidence rate ratio: 1.48, 95 % CI: 1.17-1.87) and lower during the remainder of time on OAT (0.58; 0.52-0.64). STI notification incidence was also elevated during incarceration (1.78; 1.55-2.06) and among people with meth/amphetamine recorded as a drug of concern (2.18; 1.86-2.55). OAT services are well-positioned to offer STI screening to people with opioid dependence and detect undiagnosed or untreated infections early during treatment. Subsequent testing to identify further, incident infections should be informed by individual risk factors, including sex and meth/amphetamine use.