Setback for chlamydia screening
By Daniel Cressey
The consequences of chlamydia infection are far less serious than had been feared, with the rate of complications less than a fifth of previous estimates, a major new study concludes.
While the results are good news for infected patients they come as a hefty blow to the UK's chlamydia screening program-me, which is likely to have a far lower impact than expected.
The researchers warned models on the benefits of chlamydia screening had assumed unrealistically high rates of pelvic inflammatory disease and other complications.
Study leader Dr Nicola Low, senior lecturer in epidemiology and public health medicine at the University of Bern in Switzerland, said: 'Estimates of the cost-effectiveness of chlamydia screening have been based on modelling studies that assume reproductive tract complications are common.
'We need to be much more realistic about what screening can achieve and at what cost.'
The research published in Sexually Transmitted Infections analysed data from 43,715 women in Sweden aged 15-24. The cumulative incidence of pelvic inflammatory disease by age 35 was 3.9 per cent overall and 5.6 per cent in women testing positive for chlamydia.
Yet previous models had assumed 30 to 40 per cent of infected women would eventually develop the condition.
But Dr Low added that the results did mean GPs could reassure individual patients that the chances of them becoming infertile or having an ectopic pregnancy was lower than previously thought. Infertility rates were 6.7 per cent in those who tested positive (see box).
Those involved in the UK screening programme insisted it would still be worthwhile.
Dr Sarah Gray, primary care lead in sexual health for Central Cornwall PCT, said: 'It's still worth screening to prevent short-term problems.'
Consequences of chlamydia
Unscreened Negative test Positive test
Any complication 4% 8% 11%
PID 1% 4% 5%
Ectopic pregnancy 1% 2% 2%
Infertility 2% 3% 5%