Testing for cervical Chlamydia trachomatis infection in an inner city practice

Chlamydia trachomatis in the United Kingdom: a systematic review and analysis of prevalence studies

OBJECTIVES

To undertake a systematic review to obtain estimates of genital Chlamydia trachomatis prevalence in various populations in the United Kingdom and Ireland; to determine which populations have the highest rates of infection; and to explore the most important determinants of infection.

METHODS

Electronic databases were searched using the keywords "chlamydia" and "England," "Wales," "UK," "Scotland," "Ireland," or "Britain." Additional unpublished data and references were solicited from experts. Studies were included in the analysis if C trachomatis prevalence was reported, and if they met inclusion criteria. Nine variables identified as potentially important descriptors of chlamydia prevalence were extracted from each study and analysed using various logistic regression models. Only studies reporting prevalence in female populations were included in the models, because there were few data from males.

RESULTS

357 studies were identified using the search methods, 90 of which met inclusion criteria, and 19 of which contributed to the final model. The most influential variables on prevalence were age and setting of the population tested. In general practice surgeries, the under 20 year old age group had an estimated prevalence of 8.1% (95% CI 6.5 to 9.9), 20-24 year olds 5.2% (95% CI 4.3 to 6.3), 25-29 year olds 2.6% (95% CI 2.0 to 3.3), decreasing to 1.4% (95% CI 1.0 to 1.9) in those aged over 30 years. Overall, healthcare settings had higher prevalence estimates than population based studies. For example, among under 20 year olds, estimates were 17.3% (95% CI 13.6 to 21.8) in genitourinary medicine clinics, 12.6% (95% CI 6.4 to 23.2) in antenatal clinics, 12.3% (95% CI 9.8 to 15.3) in termination of pregnancy clinics, 10.7% (95% CI 8.3 to 13.8) in youth clinics, 10.0% (95% CI 8.7 to 11.5) in family planning clinics, and 8.1% (95% CI 6.5 to 9.9) in general practice, compared to 5.0% (95% CI 3.2 to 7.6) in population based studies. The type of test, specimen used, date, and location of test were not strongly associated with chlamydia prevalence.

CONCLUSION

The chlamydia prevalence estimates by age and setting from the model may be used to inform chlamydia screening strategies. The systematic review revealed much heterogeneity in the studies identified, but with clear patterns of prevalence. It also indicated gaps in the knowledge about chlamydia prevalence in certain subgroups such as men and the general population.

Adolescence and other risk factors for Chlamydia trachomatis genitourinary infection in women in Melbourne, Australia

OBJECTIVE

To establish the prevalence of and risk factors for Chlamydia trachomatis infection to determine the role of universal versus targeted testing.

METHODS

A prospective study of 1107 women attending two sexual and reproductive health clinics in Melbourne, Australia, was carried out. A questionnaire was used to establish risk factors. Urine samples were tested for C. trachomatis by PCR. The main outcome measures were prevalence of and risk factors for C. trachomatis infection.

RESULTS

Of 1107 recruitable women, 851 (76.9%) consented and were successfully tested. C. trachomatis was detected in 18 (4.8% (95% CI 2.9 to 7.5)) of 373 women in the inner city and eight (1.7% (95% CI (0.7 to 3.3)) of 478 women in the suburban clinic. Of women under 25 years, 17 (6.2% (95% CI 3.7 to 9.8)) of 273 in the inner city in contrast with three (1.7% (95% CI 0.4 to 5.0)) of 174 in the suburban clinic were infected. In the inner city clinic, age under 25 years (OR 5.4 (95% CI 0.7 to 41.5)), vaginal discharge (OR 4.1 (95% CI 1.5 to 11.1)), and recent change of sexual partner (OR 4.6 (95% CI 1.6 to 12.9)) were associated with C. trachomatis. In contrast, in the suburban clinic, only vaginal discharge (OR 3.5 (95% CI 0.9 to 14.3)) and recent change of sexual partner (OR 3.4 (95% CI 0.8 to 15.7)) were identified as risk factors. Multivariate analysis showed that recent change of partner (OR 4.5 (95% CI 1.5 to 13.8)) was the most strongly associated independent risk factor for infection in the inner city clinic.

CONCLUSION

The high prevalence of C. trachomatis indicates that universal testing should be undertaken in the inner city clinic. Young age may not be a risk factor for C. trachomatis in more affluent populations with lower prevalence rates. No risk factors were identified with sufficient sensitivity and specificity to be useful for targeted testing. Prevalence and identifiable risk factors for C. trachomatis are not transferable between populations, even in the same city.

A retrospective review of positive chlamydial cultures in emergency department patients

This study evaluated the accuracy of diagnosis and treatment of chlamydial infection based solely on clinical presentation in the emergency department (ED). The signs and symptoms of women with chlamydial infection confirmed by cervical culture were identified and compared between appropriately treated and nontreated groups to determine which clinical features tended to lead to the correct or incorrect diagnosis. The study also determined which signs and symptoms were consistently present in the entire study group. Two hundred thirty-three charts of female ED patients with positive cervical chlamydial cultures were obtained via computerized records from the microbiology lab and reviewed retrospectively. Only 20% of the patients were correctly diagnosed as having a sexually transmitted disease and only 24% were properly treated during their initial ED visit. Although abdominal pain and vaginal discharge were the most frequent symptom and sign, only 70% and 54% of all patients had these clinical manifestations, respectively. Patients with vaginal discharge and cervical motion tenderness were significantly (P < .01) more likely to be treated in the ED. Patients with urinary tract symptoms and pregnancy were significantly (P < .01) less likely to be treated in the ED. Cervical cultures should be performed during all pelvic examinations because of the variability in the clinical presentation of chlamydial infection. A follow-up system must be in place to identify positive cultures and locate patients to ensure appropriate treatment.