Background: Free testing, treatment and extensive information campaigns are used to monitor and control the incidence of Chlamydia trachomatis infections in Norway. Most programmes have 15 to 25 year-olds as their target, because of the high incidence of infection in this age group. The potential role and effect of internet-based commercial testing has not previously been assessed in this context.
Material and methods: 1458 urine samples, taken by the patients themselves, were collected from March 2005 to September 2006 according to instructions given on the commercial web site www.testselv.no, and sent to a given address for analysis. Sex, age distribution and prevalence of Chlamydia trachomatis infection were assessed and all costs were paid by the patient buying the service.
Results and interpretation: More men than women used this service, in contrast to the sex distribution seen in public screening programs. The mean age was 28 years, the 25 % percentile and the 75 % percentile was 24 and 32 years, respectively. The prevalence of infection was high; 7.5 % in women and 12.5 % in men. Our study identifies a demographic group with a high incidence of Chlamydia trachomatis infection that has not been previously been targeted by public screening programmes.