Objective: To define utility of age and cervical findings in predicting infection with Chlamydia trachomatis and Neisseria gonorrhoeae among women universally tested for both infections, and to assess the independent contribution of Gram stain (GS) smear of endocervical secretions.
Methods: Visits by women to Seattle sexually transmitted diseases clinics from 1995 through 1999 were retrospectively reviewed. All women had endocervical GS and cultures for C trachomatis and N gonorrhoeae performed. Predictive values of age, cervical signs, and inflammation on GS (more than 30 polymorphonuclear leukocytes per 1000x field) were calculated.
Results: Among 6230 women, prevalence of C trachomatis and N gonorrhoeae was 6.9% and 2.1%, respectively; 520 women (8.3%) had either organism detected. Age, cervical signs (mucopus, induced bleeding), and inflammation on endocervical GS were independently associated with infection. However, the positive predictive value (PPV) of any cervical finding for infection was less than 19% in women 25 years and older. Inflammation on endocervical GS was the sole indicator of infection in 79 of 520 (15%) infections, but was insensitive in the absence of mucopurulent cervicitis (sensitivity, 26%; PPV, 21%).
Conclusion: Cervical signs suggesting chlamydial or gonococcal infection have higher positive predictive value (PPV) in younger women. The PPV of inflammation on endocervical GS is too low to recommend its use to direct empiric treatment in the absence of mucopurulent cervicitis, especially in women 25 years and older. Further, its low sensitivity in detecting infection in women without mucopurulent cervicitis does not justify routine use. Signs suggesting mucopurulent cervicitis should be interpreted in the context of age, and empiric treatment may not be indicated in women aged 25 years and older.