The value of tests of cure following cervical chlamydial infection

Test of cure (TOC) was performed 2, 4 and 6 weeks after treatment for cervical chlamydia infection with 10-14 days of Deteclo one tablet twice daily, erythromycin 500 mg twice daily or doxycycline 100 mg twice daily. Testing was by chlamydia culture and IDEIA (DAKO diagnostics Ltd). Discrepant results were subsequently checked by immunofluorescence (Syva MicroTrak) of both sets of left over transport media. Two hundred and three patients attended on at least one occasion; 189, 146 and 107 at 2, 4 and 6 weeks respectively. Of these 127, 70 and 34, respectively, denied sexual intercourse or had consistently used condoms. Fourteen were positive over the study period by either or both methods of detection. Of 8 culture positive results 3 were negative by IDEIA. Two of these had elementary bodies (EBs) on immunofluorescence of both sets of saved transport media. One had EBs on immunofluorescence of the saved culture transport medium only. None of the 6 IDEIA positive, culture negative patients had immunofluorescent EBs in the IDEIA transport media although one had EBs in the saved culture transport medium. One IDEIA suspicious, culture negative patient had EBs in both sets of saved transport media. There was no significant difference in the rate of chlamydia detection from patients admitting to or denying unprotected intercourse. TOC has a low yield in cases of cervical chlamydial infection when there has been careful contact tracing and treatment has been completed. If TOC is performed culture should be used if available and where antigen detection methods are used confirmation should be sought for any positive results.