Part A is a randomised control trial where we compare the intervention group who will be offered home-sampling and recieve a package by mail (containing information on urogenital C.trachomatis infections, sampling eqiupment for urine tests and a questionnaire) with a control group who will continue with todays system of conventional sampling at the doctores office (no intervention). The study population are all men and women between 18-25 years of age in Rogaland County in Norway. The population register will be used to randomly assigne to either the intervention group or the control group.The intervention group will be asked to take a urine sample and send this by mail to the laboratory for analysis within three months after the invitation, and to fill out and return a questionnaire. For the ones in the control group all samples(urethral or cervical swabs or urine samples)taken within the same three months will be sendt to the same laboratory. In this part of the study we will measure the yield ratio for the tested, diagnosed and treated in the two groupsafter the study period of three months. All samples either obtained at home or at the physician's office, will be analyzed by BDProbeTec ET Chlamydia Amplified DNA assay. This is a well documented Nucleid Acid amplification method. Samples will be analysed according to manufactures instructions. Data on number of tested and diagnosed in the two groups will be collected from Stvanger University Hospital. Data on number of treated will be collected from the Norwegain Prescription Database by merging the study dataset with their datafiles. This way we will recive information on who has received treatment for C.rachomatis within one month after after a positive C.trachomatis test.