Background Urogenital infections by Chlamydia trachomatis (CT) are the most prevalent sexually-transmitted bacterial diseases in women. Cost effective screening of women for C. trachomatis infection in developing countries is highly desirable for reducing morbidity and complications like pelvic inflammatory diseases, ectopic pregnancy and infertility. Results of noninvasive urine samples tests for C. trachomatis are nearly identical to samples collected directly from the cervix or urethra. The present study used the pooled urine samples to decrease the cost of screening for C. trachomatis.

Methods First void urine samples were collected from 1000 asymptomatic pregnant women having gestational age less than 24 weeks attending the Antenatal Clinics at PGIMER, Chandigarh during July 2009 to June 2012. The pooled urine samples (5x pooled processed specimen) were tested for presence of C. trachomatis by Amplicor CT PCR kit (Roche Diagnostic) and positive results were further tested separately on each urine sample. Direct fluroscent antibody test (DFA) assay was used on urine specimen which were positive by PCR to confirm the positive results.

Results Overall C. trachomatis infection tested by both PCR and DFA was present in 1.6% (16/1000) of asymptomatic pregnant women. A total of 200 pools of urine samples were tested and 20 pools were positive for C. trachomatis. When these pools were tested individually, 20 (10%) samples were positive for CT (In one pool, 2 samples were positive and one pool was false positive). Four samples were negative by DFA. Pooling of urine samples saved 70% of reagent costs in our study.

Conclusions The study shows C. trachomatis infection was present in 1.6% of pregnant women which indicates low prevalence of infection in northern India. Pooling of urine samples saved labour, cost (70% reduction) and time in screening large number of samples in resource-limited settings.

Disclosure of interest statement None (No conflict of interest). The study was funded by Indian Council of Medical Research, New Delhi. No pharmaceutical grants were received in the development of this study.