Chlamydia trachomatis among patients infected with and treated for Neisseria gonorrhoeae in sexually transmitted disease clinics in the United States.

BACKGROUND For two decades, treatment guidelines for sexually transmitted diseases (STDs) have recommended empirical co-treatment for chlamydia when patients are treated for gonorrhea. Because the epidemiology of and diagnostic testing for STDs have changed over time, co-treatment may no longer be needed as a clinical or public health strategy. OBJECTIVE To assess the prevalence of chlamydia among patients at STD clinics who are infected with and treated for Neisseria gonorrhoeae and to determine whether co-treatment recommendations are still justified. DESIGN Cross-sectional analysis of data from a multisite study. SETTING Five public STD clinics (Baltimore, Maryland; Denver, Colorado; Long Beach, California; Newark, New Jersey; and San Francisco, California), July 1993 through October 1995. PATIENTS 3885 heterosexual patients (2184 men and 1701 women) who agreed to participate in a trial of counseling interventions and had conclusive results from diagnostic tests for gonorrhea and chlamydia performed routinely as part of the trial. MEASUREMENTS Infection with Chlamydia trachomatis as determined by polymerase chain reaction. RESULTS Chlamydia trachomatis was detected in 20% (95% CI, 16% to 24%) of 411 men and 42% (CI, 35% to 50%) of 151 women with laboratory-confirmed N. gonorrhoeae. Chlamydia trachomatis was detected in 19% (CI, 15% to 22%) of 410 men and 35% (CI, 28% to 43%) of 154 women with treatment indications for gonorrhea who would not otherwise have been treated for chlamydia: chlamydia prevalence among these patients was significantly higher than among patients without treatment indications for either gonorrhea or chlamydia: 7% in men and 9% in women (relative risk, 2.58 [CI, 1.92 to 3.47] and 4.12 [CI, 3.05 to 5.57], respectively). CONCLUSION The frequent presence of chlamydia among patients at STD clinics who received treatment for gonorrhea, including sex partners of gonorrhea-infected patients, supports continuing current recommendations for co-treatment.