Does the Hazard of Chlamydia Increase with the Number of Gonorrhea Diagnoses? A Large Population-Based Study Among U.S. Army Women.

BACKGROUND: In the U.S. military, chlamydia and gonorrhea are common sexually transmitted infections, especially among female service members. The aim of this study was to determine whether the number of gonorrhea diagnoses sustained an increased hazard of chlamydia among military women.

METHODS: This population-based study involved an analysis of all female gonorrhea cases in the U.S. Army reported in the Defense Medical Surveillance System between 2006 and 2012. The effect of the number of gonorrhea diagnoses on the hazard of chlamydia was analyzed using the Prentice-Williams-Peterson gap-time model.

RESULTS: Among 3,618 women with gonorrhea diagnosis, 702 (19.4%) had a subsequent chlamydia diagnosis yielding a rate of 6.06 (95% CI = 5.63-6.53) cases per 100 person-years. Compared to women with one gonorrhea diagnosis, the hazard ratio of chlamydia for women with two gonorrhea diagnoses was 5.09 (95% CI = 4.42-5.86) and for women with three gonorrhea diagnoses was 6.53 (95% CI = 3.93-10.83). The median time to chlamydia diagnosis decreased from 2.39 to 0.67 years for women with two to three gonorrhea diagnoses.

CONCLUSIONS: The hazard of chlamydia increased significantly with the number of gonorrhea diagnoses and the median time to chlamydia diagnosis decreased with an increasing number of gonorrhea diagnoses among U.S. Army women.