Barbara Moscicki

The use and limitations of endocervical Gram stains and muco urulent cervicitis as predictors for Chlamydia trachomatis in female adolescents

We evaluated the presence of polymorphonuclear cells on endocervical Gram stains and clinical indices of cervicitis as predictors of Chlamydia trachomatis infection in 193 sexually active female adolescents; 148 (77%) subjects had no complaints. C. trachomatis was isolated from 34 (18%) subjects. The incidence of C. trachomatis differed by race: it was isolated from 30% of black subjects and 7% of nonblack subjects. Polymorphonuclear cells on Gram stains were found to be associated with the presence of C. trachomatis (chi 2 = 33.2, p less than 0.0001). The sensitivity, specificity, and positive predictive value for polymorphonuclear cells to predict the presence of C. trachomatis were 91% (31/34), 65% (103/159), and 36% (31/87), respectively. When examined by ethnicity, polymorphonuclear cells remained significantly associated with C. trachomatis for black subjects (chi 2 = 24.3, p less than 0.001) but not for nonblack subjects (chi 2 = 2.49, p less than 0.1). Mucopurulent discharge, friability, or erythema-edema of ectopy were not reliable indicators for C. trachomatis. Endocervical Gram stains alone are useful to identify populations at risk for C. trachomatis infection. Caution must be advised when interpreting data from different population groups because of the variability in C. trachomatis prevalence.

Evaluation of fluorescein-conjugated monoclonal antibody test to detect Chlamydia trachomatis endocervical infections in adolescent girls

We evaluated the fluorescein-conjugated monoclonal antibody (FA) test for screening for Chlamydia trachomatis endocervical infection in a general adolescent clinic. Three hundred sixty-three consecutive adolescent girls, ages 13 to 20 years (mean 17.3 years) were examined. Forty-five (12%) FA smears had insufficient cells. Reason for visit included non-lower genital tract-related disorders in 241 (76%) girls, and lower genital tract-related disorders in 77 (24%). C. trachomatis was isolated by tissue culture in 46 (14%) patients, and Neisseria gonorrhoeae by culture in 22 (7%), and Trichomonas vaginalis was identified by wet mount in 13 (5%). Compared with our tissue culture technique, the performance of the FA test was as follows: sensitivity 61% (28 of 46), specificity 97% (264 of 272), positive predictive value 78% (28 of 36), and negative predictive value 94% (264 of 282). There was no significant difference in test performance by race, although the sensitivity rate (64%) of the test in blacks was twice that (30%) in nonblacks. This apparent difference in test performance by race may actually represent variations in group characteristics, including exposure rate, susceptibility, and number of inclusion forming units available for tissue culture of Chlamydia in blacks compared with nonblacks. In our adolescent clinic, the tissue culture is superior to FA in detecting Chlamydia. We recommend that the FA test be used where tissue culture isolation for Chlamydia is not readily available, where known or predicted chlamydial infection rates are high, and where known or predicted numbers of inclusion forming units of Chlamydia in tissue culture are high.

Trypan blue staining to determine vaginal exposure in two types of plastic vaginal applicators containing two different microbicide formulations.

Dye staining of applicators has been shown to be a reliable and objective method to test vaginal insertion in clinical microbicide trials, but different plastics, dyes, and product formulations may impact the accuracy of this method. Reportedly used applicators returned from 3 clinical trials were stained with 1% trypan blue. In a phase 1 study (VivaGel), using gel-filled HTI polypropylene applicators, 1271 (97%) of applicators stained positive. In a phase 1 and a phase 2a study (LACTIN-V) using linear low-density polyethylene applicators to deliver a dry powder formulation, 57 (95%) and 135 (86%) tested positive, respectively. Dye staining of vaginal applicators is an objective low-cost measure suitable for low-resource settings.

17 USE OF CHLAMYDIAL MONOCLONAL ANTIBODY TEST TO DETECT C. TRACHOMATIS ENDOCERVICAL INFECTIONS IN ADOLESCENT FEMALES

We compared the immunofluorescent monoclonal antibody, Microtrak (MT) for screening for C.trachomatis (CT) endocervical infection in a general teen clinic population. 360 consecutive subjects aged 13–19 yrs (x = 17.0) were studied. 50(14%) smears had insufficient cells for MT and 4 CT cultures were not evaluable yielding 306 paired results for comparison. GU related problems were the stated “reason” in 110 (36%) visits. There were 40 (13%) culture (+) and 36 (12%) MT (+). Results are:Conclusions: Neither the sensitivity, specificity, or predictive value (+) of the MT suggest it will be useful in screening for CT in a general teen clinic population. These results indicate that MT would be best used in testing for CT in a high risk population where culture is not available.