Background : The prevalence of sexually transmitted infections by Chlamydia trachomatis has increased during the past 10 years in France. In 2006, a national survey including biological samples showed that prevalence was highest for those aged 18-24 years: 3·6% in women and 2·4% in men. To increase C trachomatis screening, the French National Institute in Health Prevention and Education has decided to use web-based promotion of a self-collected and mailed specimen [extrait du résumé de la communication]. Cette communication fut présentée lors de la conférence internationale "Public Health Science" qui a eu lieu à Londres le 29 Novembre 2013. Le résumé de cette communication a été cité dans la revue "The Lancet" dans le supplément 3, volume 382.