The use of cervical cytology to identify women at risk for chlamydial infection.

Testing asymptomatic women for chlamydial infection is advocated for high-risk populations, but testing criteria in low-risk settings are less clear. To determine whether findings from Papanicolaou (Pap) smears could identify women at risk for Chlamydia, we studied 512 women, 18 to 50 years of age, seeking routine gynecologic care. The prevalence of positive cultures for Chlamydia was 4.7%. Three cytologic findings were independently associated with Chlamydia on logistic regression: transformed lymphocytes, polymorphonuclear leukocytes, and squamous metaplasia. The sensitivity and the specificity of the presence of any two of these three findings were 75% and 73.6%, respectively. The prevalence of Chlamydia if two findings were present was 12.2%, nearly three times the population prevalence. Certain findings on cervical cytology may be useful as an adjunct in preventive care for chlamydial cervicitis.