High rate of chlamydia reinfection in young women
A prospective cohort study has found a high incidence and reinfection rate of chlamydia among women under 25. The researchers suggest annual screening for women aged 16-24, but sooner for women who report changing partners.
The study recruited 1,971 women aged 16-24 years from general practices, family planning clinics and GUM clinics. Urine testing for chlamydia and behavioural data were collected at baseline and every six months during follow-up, with an additional test three months after an initial positive.
Of the 1,424 women who tested negative at baseline, 777 were followed up to determine incidence. Those who tested positive (547 at baseline, 45 during follow-up) were followed up to determine the rate of reinfection.
Chlamydia incidence varied across settings, with a mean of 4.9 (95% CI 2.7-8.8) per 100 person-years for women recruited from general practice, 6.4 (95% CI 4.2-9.8) from family planning clinics and 10.6 (95% CI 7.4-15.2) from GUM clinics. However, these differences were not found to be significant after adjustment.
The rate of reinfection was highest in women recruited from general practice, with a mean of 29.9 (95% CI 19.7-45.4) per 100 person-years, compared with 22.3 (95% CI 15.6-31.8) from family planning clinics and 21.1 (95% CI 14.3-30.9) from GUM clinics. These differences were not significant.
The authors conclude that sexual behaviours determined the incidence and reinfection rates, regardless of healthcare settings.
The fact that women recruited from general practice have the highest risk of chlamydia reinfection suggests two issues: that there is ineffective sexual health promotion delivered in primary care, and that there is value in investing in chlamydia screening in general practice.
LaMontagne DS, Baster K, Emmett L et al. Incidence and re-infection rates of genital chlamydial infection among women aged 16-24 attending general practice, family planning and genitourinary clinics in England: a prospective cohort study by the Chlamydia Recall Study Advisory Group. Sex Transm Infect 2007;83:292-303Reviewer
Dr Richard Ma
GP principal, North London and staff grade in sexual and reproductive health, Margaret Pyke Centre, London