Should We Consider Alternatives To Combined Cervical And Urethral Swabs For Detection Of Chlamydia trachomatis (CT) In Females ?
- Mrinalini Mahto (mrinalini.mahto{at}echeshire-tr.nwest.nhs.uk)
- Harry Mallinson (harry.mallinson{at}hpa.org.uk)
- Clinical Microbiology and HPA collaborating Laboratory, University Hospital, Aintree, Liverpool, United Kingdom
- Published Online First 4 July 2007
Abstract
Background:The optimum specimen considered for detecting Chlamydia trachomatis (CT) has been a combined urethral and cervical swabs.
Objective: Assess the contribution of female urethral swab in CT diagnosis and consider alternatives.
Method: Urethral and endocervical samples for CT were performed on 757 sexually active female patients, > 16 years, attending GUM clinic at Macclesfield District General Hospital from October 2005- November 2006. Swabs were collected and transported to the laboratory in separate AC2 sample collection tubes and were tested by AC2 assay (Gen-Probe, San Diego).
Results: Of the 757 patients tested simultaneously by both endocervical and urethral swab, a total of 90 had CT identified by either method giving a prevalence of 11.9%. Results for urethral and endocervical swabs were concordant in 77 patients (85.6%). Eighty-two (91.1%) would have been diagnosed by swabbing cervix only but an additional 8(8.9%) were picked up by urethral swab. Urethral symptoms had been mentioned by 1 of these 8 women.
Conclusion: 8.9% infected women were positive only on urethral swab.One of these would have been picked up on presenting symptom, hence reducing the extra yield to 7.8 % thus leaving only 7 positives on 757 urethral swabs with a detection rate of 1% of all urethral swabs. Considering only a 1% yield and the discomfort of urethral swabbing, an additional urethral swab appears unwarranted on grounds of both cost and patient care. Alternatives, of endocervical swabs in first catch urine or simpler vaginal swabs have been considered based on recent studies.
