Yearly chlamydia testing 'not enough'

By Mark Pownall

GPs will need to test patients for chlamydia after every change in sexual partner if the £100 million national screening programme is to have any real impact on rates of pelvic inflammatory disease, an evaluation concludes.

Research published online by the BMJ found no evidence that screening and treatment of young women for chlamydia had any effect on the incidence of PID one year later.

The National Chlamydia Screening Programme needs a radical change of emphasis to achieve its aim of cutting NHS spending on infertility treatment, with a new focus on the most sexually active in the population, the researchers concluded.

They warned annual screening was unlikely to prevent PID, because of the high risk of infection occurring during screening intervals.

In the study, 2,529 sexually active female students filled in a questionnaire and provided a vaginal swab.

Half the swabs were tested for chlamydia immediately and women advised to visit their GP or a GUM clinic if they were positive. The swabs of the other half were stored and tested a year later, when 94% of women in both groups were followed up and evaluated.

The rate of PID was 1.3% in screened women, not significantly lower than the 1.9% in controls. Some 79% of women who developed PID had tested negative for chlamydia at baseline.

GP researcher Dr Pippa Oakeshott, reader in general practice at St George's medical school in London, said more frequent testing was needed: ‘Chlamydia screening probably does prevent PID but it is not as effective as we thought. Women should be re-tested every time they have a new sexual partner, and those who are sexually active need to get tested more than once a year.'

Dr Jessica Sheringham, Medical Research Council fellow in epidemiology and public health at University College London, said: ‘This confirms annual chlamydia screening is not enough to reduce PID. More emphasis needs to be placed on rapid testing after a change of sexual partner. This is part of the national programme, but is not being consistently delivered.'

Dr Richard Ma, a GP in Islington, north London, and a member of the National Chlamydia Advisory Group, said: ‘When a young person says they've already had a test, I ask them if they've had sex with someone new since. If so, I suggest another test.'

The findings are a further blow to the screening programme, recently rocked by a highly critical report from the National Audit Office.

BMJ 2010: 340: c1642