To determine the prevalence of and risk indicators for Chlamydia trachomatis cervical infection among women presenting for a periodic medical examination.
Centre local de services communautaires (CLSC) Saint-Louis du Parc, Montreal.
All women presenting for a routine gynecologic examination from May 1985 to July 1986. Of the 773 (99%) who agreed to participate 56 were excluded because of inadequate diagnostic tests (34), antibiotic intake in the preceding 6 weeks (19) or loss to follow-up after the initial visit (3).
Culture was the diagnostic standard, but rapid diagnostic tests were also used. From the identified cases logistic regression analysis was used to evaluate the following risk indicators: age, place of residence, use of oral contraceptives, sexual partners and frequency, history of sexually transmitted disease (STD) and abnormalities found on genital examination.
Fifty-one of the women were found to have C. trachomatis infection, for a prevalence rate of 7.1%; 32 (63%) were completely asymptomatic. Three independent indicators were found: age of 25 years or less (odds ratio [OR] 3.2, 95% confidence limits [CL] 1.8 and 5.9), cervical erythema, contact bleeding or mucopurulent exudate (OR 2.5, 95% CL 1.4 and 4.5) and residency in the CLSC area (OR 2.3, 95% CL 1.1 and 5.1). A history of STD or vaginitis had a significant protective effect in women 30 years of age or more (OR 0.2).
Case-finding for chlamydial infection could be an effective public health measure among women 25 years of age or less and among those with signs of cervicitis when they present for a Papanicolaou test.
Cites: Sex Transm Dis. 1978 Apr-Jun;5(2):51-610328031
TThe Syva MicroTrak Chlamydia enzyme immunoassay (EIA; Syva Company, San Jose, Calif.) with cytospin and direct fluorescent-antibody assay (DFA) confirmation was evaluated on 43,630 urogenital specimens over a 1-year period in the Provincial Laboratory in Regina, Saskatchewan, Canada. This was a two-phase study intended to define a testing algorithm for Chlamydia trachomatis that would be both highly accurate and cost-effective in our high-volume (> 3,000 tests per month) laboratory. The prevalence of C. trachomatis infection in our population is moderate (8 to 9%). In phase 1, we tested 6,022 male and female urogenital specimens by EIA. All specimens with optical densities above the cutoff value and those within 30% below the cutoff value were retested by DFA. This was 648 specimens (10.8% of the total). A total of 100% (211 of 211) of the specimens with optical densities equal to or greater than 1.00 absorbance unit (AU) above the cutoff value, 98.2% (175 of 178) of the specimens with optical densities of between 0.500 and 0.999 AU above the cutoff value, and 83% (167 of 201) of the specimens with optical densities within 0.499 AU above the cutoff value were confirmed to be positive. A total of 12% (7 of 58) of the specimens with optical densities within 30% below the cutoff value were positive by DFA. In phase 2, we tested 37,608 specimens (32,495 from females; 5,113 from males) by EIA. Only those specimens with optical densities of between 0.499 AU above and 30% below the cutoff value required confirmation on the basis of data from phase 1 of the study. This was 4.5% of all specimens tested. This decrease in the proportion of specimens requiring confirmation provides a significant cost savings to the laboratory. The testing algorithm gives us a 1-day turnaround time to the final confirmed test results. The MicroTrak EIA performed very well in both phases of the study, with a sensitivity, specificity, positive predictive value, and negative predictive value of 96.1, 99.1, 90.3, and 99.7%, respectively, in phase 2. We suggest that for laboratories that use EIA for Chlamydia testing, a study such as this one will identify an appropriate optical density range for confirmatory testing for samples from that particular population.