Sex equality for rapid Chlamydia screening

Infection with Chlamydia trachomatis is now the most common sexually transmitted infection in the UK. A large proportion of those infected have only mild symptoms and many have none at all. Transmission to female partners can lead to painful inflammatory disease of the pelvis and infertility. It is thought that 10 per cent of 15 to 24 year olds now carry the infection. There is a Chlamydia Screening Programme that aims to halt the spread of the condition in this age group. Test results are available after seven to ten days.

A new Chlamydia Rapid Test that gives results within one hour has been developed at the diagnostic development unit of the University of Cambridge. Its screening performance in women was reported in the BMJ in December 2007 and we summarized that report here. Compared with the slower urine polymerase chain reaction (PCR) test, the results using non-invasive self-collected vaginal swabs correctly identified 81.5% of women with infection and gave an incorrect positive result in only 1.3% of those without.

The same researchers have now reported in the BMJ an evaluation of the same test in men. They used a simple device to collect the first few drops of urine, having shown that in infected men this first collection contained a six-fold greater concentration of Chlamydia than a standard urine sample. They examined first sample collections with the new test in 1211 men attending a genitourinary medicine clinic or a young people’s sexual health centre. Standard urine samples were also sent to an accredited UK laboratory for testing for urine Chlamydia trachomatis with a PCR assay. Infection was diagnosed by PCR in 9.1% of the men. The Chlamydia Rapid Test correctly identified 82.6% of those positive by PCR and gave an incorrect positive result in only 1.5% of those without the infection, results which are very similar to those found earlier using self-collected vaginal swabs from women.

The authors concluded that using the Chlamydia Rapid Test the results from first sample urine specimens in men where as effective as vaginal swabs in women. The test could be an effective same day diagnostic and screening test for immediate treatment and contact tracing.

Sources

Nadala E-C, Goh BT, Magbanua J-P et al. Performance evaluation of a new rapid urine test for chlamydia in men: prospective cohort study. Published as pico BMJ 2009;339:389. Published online in full 28 July 2009. Accessed here 23 Aug 2009.

Mahilum-Tapay L, Laitila V, Wawrzyniak JJ et al. New point of care Chlamydia Rapid Test—bridging the gap between diagnosis and treatment: performance evaluation study
BMJ  2007;335:1190–1194. Accessed here 23 Aug 2009.