Detection of Chlamydia trachomatis infections by polymerase chain reaction in asymptomatic pregnant women with special reference to the utility of the pooling of urine specimens

Abstract

Background & objectives:

Genital Chlamydia trachomatis (CT) infections are one of the most prevalent sexually transmitted infections across the world. In pregnant women, if not detected and treated early, these may result in poor pregnancy outcomes and complications. The present study was aimed to screen CT infections from first void urine (FVU) samples of asymptomatic pregnant women using molecular methods. The secondary objective was to evaluate cost-effectiveness in pooling FVU samples for their diagnostic application.

Methods:

FVU samples were collected from 1000 asymptomatic pregnant women over a period of three years. Pooling was done by including five specimens in one pool in the amount of 10 µl and subjected to polymerase chain reaction (PCR) and further confirmed by direct fluorescent antibody assay (DFA).

Results:

The age of study participants ranged from 18 to 43 yr with the median±standard deviation of 26±3.84 yr. Majority of positive participants were younger than 25 years. A total of 200 pools were prepared and 20 of these were PCR positive. When individual specimen in 20 positive pools was tested, 20 PCR-positive specimens were identified from 19 pools, of which 16 were positive by DFA. Thus, CT was detected in 1.6 per cent asymptomatic pregnant women in India and pooling strategy resulted in 70 per cent reduction in a number of tests performed.

Interpretation & conclusions:

Our study detected C. trachomatis infection in 1.6 per cent asymptomatic pregnant women, and pooling of FVU specimens for PCR testing was found to be a cost-saving strategy in comparison to testing individual samples. Further evaluation and studies on the bigger sample size are warranted to validate these results.