Introduction Oropharyngeal Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are not routinely tested for in STI clinic attendees. Although oropharyngeal infections are often asymptomatic, they contribute to transmission in the population. Routine systematic oropharyngeal testing was implemented in men who have sex with men (MSM) in 2010, and on behavioural indication in heterosexuals, but it is unknown whether this was successful in practice. Moreover, data on oropharyngeal testing and CT/NG positivity in heterosexuals is limited.
Methods Men and women aged >16 years attending our STI-clinic between 2009- 2015 were included (n=47317). Specimens were tested using NAATs. Data were collected on demographics and sexual behaviour. Multivariable backward logistic regression analyses were used to test associations with oropharyngeal testing and oropharyngeal CT and NG. Tested determinants were age, sex, symptoms, number of sex partners and warned by (ex) partner.
Results Oropharyngeal testing in heterosexuals increased yearly from 13% in 2009 to 16% in 2015 (OR 1.3, 95% CI 1.2–1.3). In MSM, testing increased from 88% to 98% (OR1.6, 95% CI 1.5–1.8). Oropharyngeal CT positivity varied between 1.0%–1.6% in women (54/4198), between 0%–1.3% in heterosexual men (13/2226) and between 0.8%–1.5% in MSM (79/8158), but was not associated with year of testing. Oropharyngeal NG positivity varied between 1.5%–3.4% in women (123/4201), between 0.6%–4.1% in heterosexual men (61/2226) and between 2.8%–6.4% in MSM (406/8156). Oropharyngeal NG positivity increased with year of testing in heterosexual men (OR 1.2, 95% CI 1.01–1.4) and MSM (OR 1.2 95% CI 1.1–1.2).
Conclusion Routine oropharyngeal testing in MSM was successfully implemented in practice. Oropharyngeal CT positivity remained stable after increased oropharyngeal testing in all groups, and in women also for oropharyngeal NG. In heterosexual men and MSM, increased oropharyngeal testing led to increased oropharyngeal NG positivity. This justifies routine oropharyngeal testing in MSM, and warrants careful monitoring in heterosexuals.