HORMONAL FACTORS AND THE LABORATORY DETECTION OF CHLAMYDIA-TRACHOMATIS IN WOMEN - IMPLICATIONS FOR SCREENING

One thousand and fifty-six new and re-registered consecutive women att ending a genitourinary medicine clinic requiring speculum examination were screened for Chlamydia trachomatis by enzyme immunoassay (IDEIA, Dako Diagnostics Ltd). Of 1022 women who had results available for bot h cervix and urethra C. trachomatis was detected in 8.8% (89/1022) in any site, 2.3% (23/1022) in both sites, 4.9% (51/1022) at the cervix a lone and 1.5% (15/1022) at the urethra alone. Thus sampling at the ure thra increased detection by 17% (15/89). Analysis of 808 women with a regular menstrual cycle showed a significant association of combined o ral contraceptive use, age and ectropion with the detection of C. trac homatis. The detection of C. trachomatis showed a significant variatio n with the menstrual cycle (P=0.023) (relative risk (rr) 1.7 (95% conf idence intervals (CI) 1.0-2.8)). It was detected significantly more of ten in the latter part. Stepwise logistic regression analysis revealed that ectropion and age were the stronger determinants of C. trachomat is detection and not oral contraceptive use or menstrual cycle. The va riation in detection of C. trachomatis with the menstrual cycle was in dependently associated with combined oral contraceptive use and the la ck of a cervical ectropion. The increased detection at the cervix was present after the second week in combined oral contraceptive users (P= 0.008) (rr=2.3 (1.2-4.5)) but only after the 3rd week in women without an ectropion (P=0.004) (rr=2.7 (1.3-5.5)). Combined oral contraceptiv es, ectropion and youth are markers for the carriage of C. trachomatis in the lower gential tract of women. It is also detected significantl y more often in the latter part of the menstrual cycle in women who ar e oral contraceptive users.