Screening for Chlamydia infection in a sexually transmitted infection clinic: a missed opportunity?

Chlamydia trachomatis (CT) infection is the most common sexually transmitted infection (STI) reported in Europe. We aim to evaluate the overall prevalence of CT infection and the rate of asymptomatic infection in an STI clinic over a 5-year period. We will also discuss screening strategies with reference to attendees diagnosed with an STI and their sexual partners, and attendees with a non-infectious genital dermatosis.

Clinical and laboratory data for all attendees at a university hospital STI clinic over a 5-year period were reviewed. Diagnosis of CT infection was made upon polymerase chain reaction (PCR) performed in first-void urine.

The overall prevalence of CT infection was 4.0% (53/1310); the rate of asymptomatic infection was 84.9% (45/53). The prevalence of CT infection among attendees with an STI diagnosis and their sexual partners was 5.2% (50/963), whereas that among attendees with a non-infectious genital dermatosis was 0.9% (3/347; P < 0.001). Infected attendees were younger than attendees without CT infection (median age: 31 years vs. 40 years; P < 0.001). In 39.5% (17/43) of CT-infected attendees, it was possible to notify a sexual partner; CT infection was subsequently diagnosed in 58.8% (10/17) of partners.

Asymptomatic CT infection had a representative frequency, which was more pronounced among young attendees with an STI diagnosis and their sexual partners, to whom screening should be offered. Issues of age limits for screening and whether screening should be directed to males in non-STI clinic settings should be carefully assessed.