Cervical wet mount as a negative predictor for gonococci- and Chlamydia trachomatis-induced cervicitis in a gravid population.

OBJECTIVE

The purpose of this study was to determine whether a wet mount preparation of endocervical secretions from obstetric patients can accurately rule out the presence of gonococci and Chlamydia trachomatis.

STUDY DESIGN

Gravid patients were screened for gonococci and C trachomatis with a deoxyribonucleic acid probe and a wet mount preparation of endocervical secretions. The number of polymorphonuclear lymphocytes was counted and averaged per x400 high-power field. A count of <10 polymorphonuclear lymphocytes per high-power field was defined as predicting the absence of gonococci- and C trachomatis -induced cervicitis. A chi(2) analysis was used to compare the wet mount results to the deoxyribonucleic acid probe.

RESULTS

Between January and March 1998, 341 patients were enrolled in the study. Wet mount results showed 32% (108/341) of patients had <10 polymorphonuclear lymphocytes per high-power field. The incidence of infection with gonococci and C trachomatis in this population, as determined by deoxyribonucleic acid probe, was 10 of 341 (2.9%) and 30 of 340 (8.8%), respectively. The sensitivity values for gonococci and C trachomatis were 90% and 87%, respectively. The negative predictive value of the wet mount for gonococci-induced cervicitis was 99%, and that for C trachomatis -induced cervicitis was 96%.

CONCLUSION

In this population the wet mount accurately predicted the absence of gonococci- and C trachomatis -induced cervicitis. Use of this screening protocol in gravid patients has the potential to reduce the cost of screening for these 2 diseases.