Incidence of Chlamydia trachomatis infections and screening compliance, U.S. Army active duty females under 25 years of age, 2011-2014.

Reported chlamydia infection rates among active duty U.S. Army females less than 25 years old declined by 20% from 2011 to 2014 (11,028 infections per 100,000 person-years [p-yrs] to 8,793 infections per 100,000 p-yrs, respectively). An overall decline in the proportions of high-risk female soldiers tested for chlamydia occurred during the same period, declining from a high of 85% in 2011 to a low of 71% in 2012, with an increase to 80% in 2014. Chlamydia laboratory testing volume also decreased from 2011 to 2013 but the test positivity rate remained stable at 6.0%-6.4%. By using projected incidence rates based on 100% of at-risk women being screened with a stable laboratory positivity rate, there was an estimated 15% decline in chlamydia incidence from 2011 to 2014 (12,794 to 10,991 infections per 100,000 p-yrs, respectively). Surveillance for chlamydia infections must include consideration of screening program performance in addition to passive reporting.