Background: Chlamydia trachomatis is a common and curable STI that may be symptomatic or asymptomatic. The few studies on C. trachomatis among Iranian women have had, for the most part, small sample sizes and are therefore unsuitable for epidemiological deductions. The aim of this study was to estimate the prevalence of urogenital C. trachomatis infections by PCR on urine samples of married women in their fertile years in order to determine the need for a C. trachomatis screening program for asymptomatic women in Iran.

Methods: This descriptive-analytical and cross-sectional study was performed on 991 married women. The research material consisted of questionnaires and urine samples, which were transported daily to Avesina Research Institute, Tehran, Iran, to extract their DNA and prepare them for PCR tests. The gathered data were analyzed by SPSS, version 13, and evaluated statistically by t-test, chi-square test, Fisher's exact test and logistic regression, considering p<0.05 as significant.

Results: Of all the subjects, 127 (12.8%) were positive by PCR for C. trachomatis. The mean age of the participants was 28.88± 6.19 years. Infection was more prevalent among those with lower levels of education, who were employed and not pregnant. This infection was more prevalent among those who were using contraception, especially condoms. Reproductive history revealed that infection was more prevalent among participants with a history of vaginal discharge, pelvic pain, infertility and low birth-weight infants, and less prevalent among those with a history of abortion, preterm delivery and ectopic pregnancy. However, these patterns were not statistically significant.

Conclusion: In populations with C. trachomatis prevalences higher than 4%, screening programs are recommended. Thus, Chlamydia screening should be part of the health care program in Iran to reduce the burden of this disease.