Chlamydia screening "may not protect against pelvic inflammatory disease"
It is unlikely that single screening for chlamydia will prevent women developing pelvic inflammatory disease in the following year, according to research published on bmj.com today.
The study concludes that most cases of pelvic inflammatory disease occurred in women who did not have chlamydia infection when they were screened, suggesting they may have become infected later.
The authors call on policy makers to publicise the recommendations of the national chlamydia screening programme that in addition to annual screening, individuals should be tested for chlamydia whenever they have a new sexual partner.
Chlamydia often has no symptoms and remains undiagnosed. This is concerning because untreated chlamydia in women can lead to pelvic inflammatory disease (PID) which can result in infertility, chronic pelvic pain and ectopic pregnancy.
The authors, led by Dr Pippa Oakeshott from St George's, University of London, recruited 2,529 sexually active female students between the ages of 16 to 27 from 20 universities and further education colleges in London.
The results show that 68 (5.4%) out of 1,254 women who were screened immediately had chlamydia and 75 (5.9%) out of the 1,265 screened a year later tested positive.
Fifteen (1.3%) of the immediately screened women went on to develop PID vs 23 (1.9%) of the women tested after a year. The findings also suggest an 80% reduction in the risk of pelvic inflammatory disease in women treated for chlamydial infection.
However, most cases of PID (79%) occurred in women who tested negative for chlamydia when they were initially tested, says the study. The researchers argue that this suggests that frequent testing for chlamydia aimed at high risk groups might be more effective at preventing PID than single screening.
The authors conclude that single screening is not particularly successful at reducing PID cases and may be less cost-effective than previously thought.