[Detection of endocervical chlamydia infections by comparing the Papanicolaou staining test and direct immunofluorescence].

The association of infection with Chlamydia trachomatis and cytologic changes on Papanicolaou smear was examined in 453 sexually active postmenarcal female subjects attending the cytology service for routine Papanicolaou smear. We described inflammatory and epithelial cell patterns that permit the detection of group of women with and without cervicitis at high risk for cervical chlamydial infection. We confirmed the infection by direct immunofluorescence using monoclonal antibodies. Ninety-five of 453 women had cervicitis (20.9%) chlamydial inclusions were noted by Papanicolaou in 26 patients with cervicitis and in 61 without cervicitis. Direct stain with fluorescein-conjugated monoclonal antibodies demonstrated elementary bodies of C. trachomatis in 42/453 women, 24 had cervicitis and 18 without cervicitis. One of two patients with cervical smears with chlamydial inclusions as "changes suggestive of chlamydial infection" by Papanicolaou was confirmed by inmmunofluorescence. We calculated the efficay of the Papanicolaou smear as a diagnostic technique: the sensitivity was 0.27, the specificity was 0.80, the predictive value of o positive test was 0.29. In order to compare the efficiency with immunofluorescence the sensitivity was 0.25, specificity 0.94 and the positive predictive value was 0.57. Using the epithelial changes interpreted as inflammatory, we had the highest sensitivity with both tests, 0.76 to Papanicolaou and 0.90 to immunofluorescence, specificity is near 100% for both tests, cytology tended to be more efficient in identifying women without infection than in identifying those with infection.