Risk of Pelvic Inflammatory Disease among women screened annually for Chlamydia trachomatis infection compared to women not screened, U.S. Armed Forces, 2001-2013

BACKGROUND: Pelvic inflammatory disease (PID) is a bacterial infection causing an inflammatory reaction in the upper genital tract. Even though it can be treated with antibiotics, women often delay seeking health care because symptoms are asymptomatic; delay of treatment may result in long-term sequelae such as infertility. Chlamydia trachomatis is the main etiologic agent, and all female U.S. service members <26 years old are require to be screened annually for chlamydia as part of their woman's health check-up. Hence, service women 26 years and older who are not screened annually and are asymptomatic for chlamydia, may not receive treatment and may therefore be at higher risk to develop PID. This presentation will discuss the impact of annual chlamydia screening on PID health outcomes among U.S. services women over a 13-year period. It was hypothesized that women not screened for chlamydial infection on a regular basis are at higher risk for developing PID compared to women who were screened annually.

METHODS: This retrospective cohort study utilized the Defense Medical Surveillance System (DMSS). Females entering military service from January 1, 2001 to December 31, 2010 were stratified by age (<26, >=26) and followed until they were discharged from military service or until the end of the surveillance period, December 31, 2013; basic training periods were excluded because the Services implemented different recruit chlamydia screening policies during the surveillance period. Counts, rates, and trends over time were provided for the descriptive analysis, multivariate logistic regression was used to assess the effect of covariates. and hazard analysis was employed to characterize risk over time.

RESULTS: Between January 2001 and December 2013, 18,544 female service members met the case definition of PID. Overall, the incidence rate was stable at approximatley 7.5 per 1,000 person-years, but higher (11.5 per 1,000 person-years) among women <26 years old. Rates were higher among service women in the Army compared to all other services. Other risk factors included being of black, non-Hispanic race/ethnicity, enlisted rank, and married. Risk for PID for Army service women increased after 6 months post-accession.

CONCLUSIONS: PID rates were overall stable during the surveillance period, but higher among service women <26 years old and the group receiving annual chalmydia screening. This suggests that annual chlamydia screening programs alone may not reduce PID incidence in an at-risk female military population.