Does that new practice have the X factor for you?
Q I've heard there is a new test for chlamydia that involves taking a vulval swab. Tell me more.
A Non-invasive testing for chlamydia genital infection using a special vulvo-vaginal swab is now available.
The improved sensitivity and specificity of current molecular diagnostic tests – nucleic acid amplification test (NAAT ) – for chlamydia has facilitated this development.
Depending on which NAAT is used the sensitivity and specificity value for a vulvo-vaginal swab is similar to that of a cervical swab using the same test. It opens up the possibility of female patients taking their own specimens and avoiding genital examination – an issue with the younger adolescent age group 16-19 years, where the incidence of chlamydia is highest. The method is generally seen to be acceptable by female patients.
Chlamydia is now the commonest sexually transmitted infection in the UK, with 89,818 new cases in 2003, a 192 per cent rise since 1995.
The national chlamydia screening programme in England, which currently covers 25 per cent of PCTs, aims to reduce the prevalence of chlamydia in under-25s. All participating laboratories offer the service, but please check with your local laboratory before asking for a vulvo-vaginal swab.
Patients offered chlamydia testing should be given information and leaflets about the condition and its sequalae, advice on how and when they will receive the test results and if positive what treatment is available. The need for their sexual partner/s to be seen and treated to avoid re-infection should be stressed.
Olwen Williams, consultant genitourinary physician,
Wrexham Maelor Hospital