Risk analysis of pelvic inflammatory disease among u.s. military recruits, 2001-2012

BACKGROUND: Asymptomatic Chlamydia trachomatis can lead to pelvic inflammatory disease (PID) which, if untreated, can cause severe damage to the upper reproductive organs. PID can be prevented through Chlamydia screening of at-risk females until age 25. U.S. military services, except for the Army, have implemented Chlamydia screening programs for females entering recruit training. Therefore, females with asymptomatic chlamydial infection not screened during training maybe at risk for PID, even though it is unclear how recruit Chlamydia screening programs impact PID incidence. It was hypothesized that women not screened for chlamydial infection are at higher risk for PID during the 12 months following recruit training compared to women who were screened. METHODS: For this IRB approved retrospective cohort study, the Defense Medical Surveillance System (DMSS) was utilized. Females entering recruit training were followed for 12 months or until a PID diagnosis occurred. The surveillance period was January 1, 2001 to December 21, 2012. Multiple Poisson regression was used to assess the effect of covariates. Hazard analysis was employed to characterize risk over time. RESULTS: Among 304,572 female recruits, there were 5,767 incident diagnoses of PID; 51% occurred among Army servicewomen. Most PID cases (93%) occurred in women <25. The incidence rate was 76% higher in the Army. Risk for Army servicewomen increased after 6 months post-accession. CONCLUSIONS: PID rates were highest in the Army compared to all other services during the first year of active duty. This suggests that recruit Chlamydia screening programs contribute to reducing PID incidence in at-risk females.