Chlamydia trachomatis cervical infection: prevalence and determinants among women presenting for routine gynecologic examination.

OBJECTIVE: To determine the prevalence of and risk indicators for Chlamydia trachomatis cervical infection among women presenting for a periodic medical examination. DESIGN: Prevalence study. SETTING: Centre local de services communautaires (CLSC) Saint-Louis du Parc, Montreal. PATIENTS: 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). OUTCOME MEASURES: 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. MAIN RESULTS: 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). CONCLUSIONS: 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.

Comparison of three techniques for detection of Chlamydia trachomatis in endocervical specimens from asymptomatic women.

Culture in DEAE-dextran-treated HeLa 229 cells, a solid-phase enzyme immunoassay (EIA) (Chlamydiazyme; Abbott Laboratories, North Chicago, Ill.), and a direct immunofluorescence test (DFA) (MicroTrak; Syva Co., Palo Alto, Calif.) were compared for the detection of Chlamydia trachomatis in endocervical specimens from 715 asymptomatic women. Response to antibiotic therapy was also monitored at least 4 weeks after completion of therapy. An additional sample was collected at a control visit, and a second culture was performed if discrepancies were observed between the three tests. A total of 48 infections were diagnosed, for a prevalence of 6.7%. At the first visit, 37 specimens were positive by culture. The respective sensitivities of EIA and DFA were 78.4 and 81.1% and the respective specificities were 96.8 and 97.9% when compared with the cell culture technique. The positive predictive values were 56.9 and 68.2%, respectively. When the additional 11 infections detected by the second culture were included to establish a new standard of positivity, the sensitivity of the first culture was estimated at 77.1%. The positive predictive values of EIA and DFA increased to 77.6 and 83.7%, respectively. EIA and DFA performed as well as culture for control of therapy; a 100% agreement among the three techniques was observed.