Reinfections, Persistent Infections, and New Infections After General Population Screening for Chlamydia trachomatis Infection in The Netherlands:

Objectives: The objectives of this study were to determine the rate of new infections and reinfections or persistent infections with Chlamydia trachomatis to define appropriate screening intervals and to identify risk factors for reinfection. Design: This was a cross-sectional study among a subsample of participants in a population-based screening. Setting: This study was conducted in urban and rural areas in The Netherlands. Participants: A total of 21,000 15- to 29-year-old women and men were invited for home-based urine testing. One year after the study, a subsample of 299 participants were offered retesting. Main Outcome Measures: The authors studied the rate of infection with C trachomatis. Serovar determination was used to potentially discriminate between new infections and reinfections or persistent infections. Results: Nine C trachomatis infections were found among 187 responders (4.8% confidence interval, 1.7-7.9). The prevalence was 10.4% (5 of 48) in previous positives and 2.9% (4 of 139) in negatives. Three of 5 repeatedly positive participants were infected with a different C trachomatis serovar. Conclusions: Our study indicates that infected persons found in a systematic, population-based screening should be rescreened within 1 year. Optimal screening intervals still need to be determined.