Sex Transm Infect 89:63-69 doi:10.1136/sextrans-2011-050455
  • Epidemiology
  • Original article

High yield of reinfections by home-based automatic rescreening of Chlamydia positives in a large-scale register-based screening programme and determinants of repeat infections

  1. Jan van Bergen4
  1. 1Department of Infectious Disease Control, Rotterdam Rijnmond Public Health Service, Rotterdam, The Netherlands
  2. 2Epidemiology & Surveillance Unit, Centre for Infectious Disease Control, National Institute of Public Health and the Environment, Bilthoven, The Netherlands
  3. 3Department of Infectious Diseases, South Limburg Public Health Service, Geleen, The Netherlands
  4. 4STI AIDS Netherlands, Amsterdam, The Netherlands
  5. 5Cluster of Infectious Diseases, Department of Research, Online Research and Prevention Unit, Amsterdam Health Service, Amsterdam, The Netherlands
  1. Correspondence to Dr Hannelore M Götz, Department of Infectious Disease Control, Rotterdam-Rijnmond Public Health Service, PO Box 70032, 3000 LP Rotterdam, The Netherlands; hm.gotz{at}
  1. Contributors HMG was the author responsible for design of the study, analysis and writing. IVFvdB and HMG analysed the data. All coauthors were implementing partners in Rotterdam (HMG and SvR) and Amsterdam (JSAF and RHK) and South-Limburg (CJPAH and EEHGB) or had central coordination (JvB and LLP). All authors have commented on draft versions and approved the final version.

  • Accepted 26 May 2012
  • Published Online First 23 June 2012


Introduction In a systematic internet-based Chlamydia Screening Implementation Programme in The Netherlands, all chlamydia-positive participants automatically received a testkit after 6 months to facilitate early detection of repeat infections. The authors describe participation in repeat testing and prevalence and determinants of repeat infection during three consecutive annual screening rounds.

Methods Data collection included information on testkits sent, samples received and results of laboratory tests at time of baseline test and retest; (sexual) behavioural variables and socio-demographic variables were assessed. Chlamydia positives were requested to answer additional questions about treatment and partner notification 10 days after checking their results.

Results Retest rate was 66.3% (2777/4191). Retest chlamydia positivity was 8.8% (242/2756) compared with a chlamydia positivity at first screening test of 4.1%. Chlamydia positivity was significantly higher in younger age groups (14.6% in 16–19 years, 8.5% and 5.5% in 20–24 and 25–29 years; p<0.01); in participants with lower education (15.2% low, 11.1% medium and 5.1% high; p<0.001) and in Surinamese/Antillean (13.1%), Turkish/Moroccan (12.9%) and Sub-Saharan African participants (18.6%; p<0.01). At baseline, 88.7% infected participants had reportedly been treated and treatment of current partner was 80.1%.

Discussion Automated retesting by sending a testkit after 6 months to all chlamydia positives achieved high retest uptake and yielded a positivity rate twice as at baseline and can therefore be recommended as an additional strategy for chlamydia control. The high rate of repeat infections among known risk groups suggests room for improvement in patient case management and in effective risk reduction counselling.


  • Funding This work was supported ZonMW, Ministry of Health, The Netherlands, grant number 124000001.

  • Competing interests None.

  • Patient consent Obtained.

  • Ethics approval Ethics approval was provided by Medical Ethical Committee Free University Amsterdam.

  • Provenance and peer review Not commissioned; externally peer reviewed.