Background: Chlamydia trachomatis (CT) infections are common among adolescents attending high and middle schools. The study objective was to determine the reinfection rates of CT for females attending school-based health centers.
Methods: Adolescents attending school-based health centers who reported they were sexually active were screened for CT using nucleic acid amplification tests on cervical or urine samples. Between 1996 and 2003, 10,609 female students were tested. The overall annual prevalence for unduplicated students in a calendar year ranged from 15.1% to 19.5%. Reinfection was defined as a positive test result occurring between 30 and 365 days after an initial positive result.
Results: There were 897 female students who tested positive for CT and returned for at least 1 subsequent test between 30 and 365 days later. Of these, 236 had 1 or more subsequent positive tests for a cumulative incidence of reinfection in 1 year of 26.3% (95% confidence interval = 23.4–29.2%). Young age at first infection was significantly associated with increased risk of subsequent infection (P <0.01). Across sites, the cumulative incidence of reinfection in these female students ranged from 14.3% to 38.9%.
Conclusions: The chlamydia cumulative incidence of reinfection in these female adolescents attending high and middle schools was high and supports the Centers for Disease Control and Prevention recommendation to screen adolescents frequently, especially those with a history of a previous chlamydia infection.