Postal urine specimens: are they a feasible method for genital chlamydial infection screening?

A United Kingdom (UK) screening programme for Chlamydia trachomatis has recently been announced. Pilot projects involving the opportunistic testing of women attending health facilities are due to commence in several sites. There is a danger that this approach will fail to obtain adequate population coverage. The alternative--true systematic population screening--is generally assumed to be unfeasible. Studies in Denmark using postal urine specimens have challenged this assumption. No such studies have been reported from the UK.

To assess the potential of urine specimens sent by post as the basis for a UK population screening strategy for genital chlamydial infection.

Two hundred patients (100 men, 100 women) aged 18 to 45 years were randomly sampled from the list of one urban group practice. Subjects were mailed an explanatory letter, a urine sample container, a sexual lifestyle questionnaire, and a prepaid return envelope. Non-responders were contacted by telephone; persistent non-responders were visited at home. Samples were tested for Chlamydia by DNA amplification and enzyme immunoassay.

Sixty-four (32%) subjects were no longer living at their GP registered address. Of the remaining 136, 126 (93%) responded to the survey and 113 (83%) accepted the request for a urine sample and completed a questionnaire. Acceptance rates were similar for men and women and across age groups. Four samples (3%) were Chlamydia positive.

Home mailed urine specimen collection in conjunction with a self-completed postal questionnaire is feasible. This could provide a viable basis both for determining population Chlamydia prevalence and for a UK Chlamydia population screening strategy. Overall cost effectiveness of such a strategy will depend on the cost of the test used. Comparative performance characteristics of the different currently available tests in this setting have yet to be fully determined.