Repeated chlamydia infections common among young sexually active women

There is a high incidence of repeated chlamydia infections among young sexually active women. The majority of these repeated infections were due to reinfection; but there was also a high incidence of repeated infections resulting from treatment failure, according to results of a recent study.

The study’s researchers said the high number of repeated infections resulting from treatment failure indicates the need for improved male screening and partner notification programs as well as the necessity for improved antibiotic therapies.

The researchers enrolled 210 sexually active adolescent girls in Indianapolis aged 14 to 17 years. Behavioral and sexually transmitted infection assessments were conducted every three months for each study participant. These assessments included testing for sexually-transmitted diseases and questions about sexual partners, sexual frequency and condom use. The study began in April 1999 and the participants were followed until July 2009.

There were 478 episodes of chlamydia infection among the study participants. One hundred seventy-six of the participants remained uninfected throughout the course of the study. The incidence rate was 34 episodes per 100 woman-years. An algorithm was used to determine if the repeated infection was due to reinfection or to treatment failure.

Of the women who had an episode of chlamydia infection, 121 experienced more than one repeated infection, forming a total of 268 episode pairs. Of the 268 episode pairs, researchers had complete data for 183 pairs; these were classified using the algorithm.

The results demonstrated that of the repeated infections, 84.2% were “definite, probable or possible” reinfections; 13.7% were “probable or possible” treatment failures; 2.2% persisted without documented treatment.

Batteiger B. J Infect Dis. 2009;201:42-51.