Chlamydia infection can have serious health consequences but often produces no immediate symptoms. Research workers from Cambridge, London and Birmingham reported their evaluation of a new Chlamydia Rapid Test as a potential test for diagnosis and screening in the British Medical Journal of 8 December 2007. The study was carried out on 1349 women aged over 16 years who attended one sexual health centre and two genitourinary medicine clinics. Each woman collected a urine sample and at least one swab from her lower vagina, a procedure which most (96%) found acceptable.

The new CE marked test is based on an extraction from a vulvovaginal swab using a premeasured solution, adding five drops of the extracted material to dissolve freeze-dried reagents and then applying it to a test strip coated with an antibody to a chlamydial marker called lipopolysaccharide. After 25 minutes the presence of a blue line indicates a positive result.

The ‘gold standard’ test for Chlamydia trachomatis infection in women is nucleic acid amplification by the polymerase chain reaction (PCR) on material from a swab taken from the inner wall of the cervix, an invasive procedure. These swabs can not be taken at a sexual health clinic and therefore the new test was compared instead with the results from urine specimens sent to a laboratory accredited by the UK Accreditation Service for testing for Chlamydia trachomatis with a PCR assay. That assay showed that infection rates varied from 6.0% to 8.3% at the three study sites.

Compared with the urine PCR results, the new test correctly identified 81.5% of women with chlamydia and gave an incorrect positive result in only 1.3% of those without the infection. The authors concluded that the Chlamydia Rapid Test with self-collected vaginal swabs would be an effective same day diagnostic and screening test, allowing for immediate treatment and contact tracing. They also suggested that it would be an effective and economic method for screening in populations where resources are limited.