Screening for Chlamydia trachomatisBMJ 1998; 317 doi: https://doi.org/10.1136/bmj.317.7159.680a (Published 05 September 1998) Cite this as: BMJ 1998;317:680
New methods are needed to assess the burden of illness from chlamydia
- I Simms, Senior scientist (epidemiology).,
- G Hughes, Principal scientist (epidemiology).,
- M Catchpole, Consultant epidemiologist.
- HIV and Sexually Transmitted Diseases Division, Public Health Laboratory Service Communicable Disease Surveillance Centre, London NW9 5EQ
- Victoria Hospital, Kirkcaldy, Fife KY2 5AH
- Department of Sexual Health, Clinic 5, Hertford County Hospital, Hertford SG14 1LP
- New York Hospital, Cornell Medical Center, 525 East 68th Street, Box 392, New York, NY 10021, USA
- Middlesbrough General Hospital, Middlesbrough TS5 5AZ
EDITOR—Boag and Kelly's editorial is a useful review of some of the issues raised in the recently published summary of the findings of the chief medical officer's expert advisory group on genital chlamydial infection.1 If successfully implemented, these recommendations would be one of the most important public health interventions in controlling communicable diseases of the past 25 years. However, they do not address the issue of how the proposed screening programme might be evaluated.
Boag and Kelly imply that successful intervention would reduce the incidence of infertility. Although this may be true, monitoring rates of infertility is unlikely to provide a reliable or timely measure of the true impact of intervention. Firstly, genital chlamydial infection is associated with only about 75% of cases of tubal factor infertility, which in turn is thought to account for only 36% of all cases of infertility. 2 3 Secondly, the highest prevalence of genital chlamydial infection is seen in women aged 16 to 19, but more women are becoming pregnant later in life.4 Women are thus likely to seek advice about infertility many years, perhaps even decades, after infection. Thirdly, other factors such as expectations of the success of treatment might influence the number of women seeking infertility treatment.
Boag and Kelly also imply that the promised pilot studies would show whether reductions in morbidity could be achieved through intervention. This is unlikely to be the case until new measures are developed for monitoring the burden of illness associated with chlamydial infection, particularly pelvic inflammatory disease, which accounts for much of the illness associated with this infection. Although the prevalence of chlamydial infection may be reduced in the short term by screening, this would not necessarily reflect a corresponding decrease in pelvic inflammatory disease. Short term reductions in prevalence may be associated with reduced duration …