A comparison of self-taken vulvovaginal and cervical samples for the diagnosis of Chlamydia trachomatis infection by polymerase chain reaction

Abstract

Implementation of the National Chlamydia Screening Programme in Cornwall commenced in April 2003. Initially, women in community venues were screened using urine samples. However, many of these urine samples were inhibitory to polymerase chain reaction (PCR), resulting in a high recall rate for women in the programme. The decision to switch to self-taken vulvovaginal samples led us to carry out an in-house validation of this sample compared with endocervical samples. Data from 333 women were analysed. Of the endocervical samples, 15.9% were positive compared with 16.8% vulvovaginal samples. This difference between positivity rates in cervical and self-taken vulvovaginal samples is not significant. Equivocal results occurred with 4.7% of the vulvovaginal samples but were not seen with the endocervical samples. Self-taken vulvovaginal samples are acceptable to women, as sensitive as endocervical swabs and more suited to PCR testing with the Roche COBAS Amplicor system than urine samples.