Chlamydia in colposcopy clinics: to screen or not to screen?

The objective of the study was to assess the prevalence of Chlamydia trachomatis in our colposcopy clinic. A total of 337 consecutive patients newly referred to the colposcopy clinic between May and November 2003 were screened for chlamydia trachomatis. All our patients were referred by their GPs and none of the patients had had a recent chlamydia test performed. Four patients screened positive, overall giving a prevalence of 1.2% [95% CI 0.04-2.36%]. Three of those with positive results were in the 21 - 30 year age group (139 in the group, which equals 2.2% prevalence [95% CI 0 - 4.6%]). The fourth positive result was in the group over the age of 60. None of those screened in the other age groups was positive (< or =20, 31 - 40, 41 - 50, 51 - 60 years). Numbers screened in each of those groups were: 14, 115, 53 and 12, consecutively. Our study, though small in sample size, supports the view that the prevalence of chlamydia is not high in all colposcopy clinic attenders. Women younger than 30 years old are more likely to be infected than older women; hence opportunistic screening should target this age group. The prevalence rate may be low due to the enzyme linked immunosorbent assay giving a poor detection rate for chlamydia screening.