Authors' objectives:

To examine data on the effectiveness of screening for chlamydial infection by a physician or other health care professional. Specifically, we examine the evidence on the effectiveness of screening strategies in nonpregnant women, pregnant women, and men; the accuracy of tests used for screening; and evidence that early treatment of chlamydial infection improves health outcomes. This review updates the literature since the last recommendation of the U.S. Preventive Services Task Force (USPSTF) published in 1996.

Authors' results and conclusions: Nonpregnant women: The initiation of screening programs in multiple settings and communities is associated with declines in chlamydial infection prevalence rates in the populations they serve. Changes in population prevalence rates have not been well documented since few studies have employed a representative population sample. Age continues to be the best predictor of chlamydial infection in women, with most studies evaluating cutoffs at age younger than 25 years. Other risk factors may be useful predictors, but these are likely to be population specific. To determine the accuracy of screening tests for women, we retrieved and critically reviewed 33 papers on test performance. Results indicate that when DNA amplification tests are used, cervical swab specimens and first void urine specimens have similar and have better sensitivity than endocervical culture. The results of a randomized controlled trial conducted in a large health maintenance organization indicate that screening women selected by a set of risk factors reduces the incidence of pelvic inflammatory disease (PID) for a 1-year period. Recurrent chlamydial infections in women have been associated with increased risks for PID and ectopic pregnancies. Pregnant women: Few previous studies described risk factors for chlamydial infection in pregnant women, and these tended to be small and descriptive. Nonculture-testing techniques appear to perform well in pregnant populations, although studies are limited. A Cochrane review of 11 trials of interventions for treating genital chlamydia infection in pregnancy concluded that amoxicillin was as effective as erythromycin for achieving microbiological cure. The second Task Force recommendations for screening pregnant women were based on 2 studies in which improved pregnancy outcomes were demonstrated after patients were treated for chlamydial infection. We identified no recent studies on this topic in our literature search. Men: Studies of prevalence rates and risk factors for chlamydial infection in men are limited. Being younger than 25 years of age is the strongest known risk factor cited so far. Results of swab specimens compared with first void urine specimens were similar for DNA amplification tests. DNA amplification techniques offer improved sensitivity and are more readily available than culture. The results of clinical trials indicated that azithromycin and doxycycline are equally efficacious, and both are more efficacious than erythromycin. Despite better compliance with single-dose treatment with azithromycin than multiple-dose treatment with doxycycline, cure rates are similar. No studies described the effectiveness of screening or early treatment for men in reducing transmission to women or in preventing acute infections or complications in men.

Authors' recommendations: Evidence for the effectiveness of screening nonpregnant women at risk has improved since the last recommendations from the USPSTF. There is growing evidence for the high performance of the new DNA amplification tests in which either endocervical swabs in women, urethral swabs in men, or urine specimens from men and women are used. No studies were found that described the effectiveness of screening or early treatment for men in reducing transmission to women or in preventing acute infections or complications in men.

Authors' methods: Systematic review

Project Status: Completed

URL for project: http://www.ahrq.gov/clinic/uspstf/uspschlm.htm

Year Published: 2001

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: United States

Organisation Name: Agency for Healthcare Research and Quality

Contact Address: Center for Outcomes and Evidence Technology Assessment Program, 540 Gaither Road, Rockville, MD 20850, USA. Tel: +1 301 427 1610; Fax: +1 301 427 1639;

Contact Name: martin.erlichman@ahrq.hhs.gov

Contact Email: martin.erlichman@ahrq.hhs.gov

Copyright: Agency for Healthcare Research and Quality (AHRQ)