Background The bacterial load of Chlamydia trachomatis (CT) infected individuals may indicate the likelihood of further transmission and development of sequelae. For the first time, we compared the urogenital CT-load of men and women diagnosed by general practitioners (GPs), hospital physicians and the STI clinic.

Methods All urogenital nucleic acid amplification tests (NAAT) CT-positive samples (n=3, 588) from the Maastricht Medical Microbiology Laboratory were included in the analyses (2012–2016). The cycle quantification (Cq)-value of the NAAT was used as an inversely proportional measure for CT-load (Cq-values and CT/ml values were highly correlated, Pearson’s r:-0.8). Multivariable linear regression analyses were used to compare urogenital Cq-values between STI care providers (GPs, hospital physicians, STI clinic) and assess potential associated demographic- and coinfection determinants, stratified by sex. Adjusted mean differences of Cq-values are presented using betas (B) and 95% confidence intervals (95%CI).

Results Urogenital Cq-values were similar in men visiting the GPs (B:0.2;95%CI: −0.3 to 0.7) and hospital physicians (B:0.4;95%CI: −0.8 to 1.6) compared to the STI clinic. Women visiting the GP had significantly lower urogenital Cq-values (B:-1.0;95%CI: −1.6 to −0.3) compared to the STI clinic. Women visiting the hospital had higher urogenital Cq-values (B:1.1;95%CI: 0.2–2.0) compared to the STI clinic. Among women visiting the STI clinic, urogenital Cq-values were lower in women with concurrent anorectal CT (B: −3.1;95%CI: −3.8 to −2.3) compared to anorectal CT-negative women.

Conclusion Male patients visiting different STI care providers had similar CT-loads. The higher CT load of women visiting the GP compared to STI clinic women could be indicative for higher transmission potential and sequelae. Women visiting hospital physicians had lower CT loads likely due to time of diagnosis. Notably, STI clinic women with concurrent anorectal CT had substantially higher urogenital CT-loads. This finding indicates a missed opportunity in GP and hospital physician patient management, as they rarely test anorectally, while anorectal CT is common among women.

Disclosure No significant relationships.