Background England’s National Chlamydia Screening Programme (NCSP) recommends that sexually active people <25 years test for Chlamydia trachomatis annually and on change of sexual partner. Since 2013, NCSP has also recommended re-testing three months after testing positive. We used a detailed dataset to investigate characteristics associated with repeated chlamydia testing.

Methods We used surveillance data of community-based chlamydia testing (excluding online testing and specialist sexual health services) among men and women aged 15–24 years in the Bristol area, January 2011-December 2017. Repeat-testing was defined as returning for further testing within the Bristol area, at least 42 days after initially testing. Initial tests <3 months from December 2017 were excluded. We used logistic regression to compare odds of repeat-testing by initial test result, testing service, residence, initial test result and sexual risk behaviour, adjusted for age and whether the 2013 guidance was operating.

Results 14.11% (n=76,758) of women and 7.81% (n=28,038) of men repeat-tested within the study period. Of those with a positive result, 31.21% (n=5,104) of women and 14.88% (n=2,386) of men repeat-tested. Repeat-testing was associated with positive initial tests (Females: Adjusted Odds Ratio 1.90, 95% Confidence Interval 1.76–2.05; Males: 1.98, 1.71–2.27), having ≥2 sexual partners in the last year (1.17, 1.11–1.23; 1.15, 1.02–1.31), having a new sexual partner in the last 3 months (1.31, 1.24–1.38; 1.55, 1.36–1.77), living in the city of Bristol (1.68, 1.57–1.80; 1.43, 1.25–1.65) and testing through Contraception and Sexual Health clinics, which can treat uncomplicated infections, rather than other settings (1.34, 1.28–1.41; 1.37, 1.23–1.53).

Conclusion It was encouraging that initial positive tests and riskier sexual behaviour, which mean individuals are more likely to be infected, were associated with re-testing. However, we observed low uptake of re-testing with disparities by residence and testing service. These results will inform strategies to increase the uptake of re-testing within the Bristol area.

Disclosure No significant relationships.