Introduction About 300 million new infections of gonorrhoea, Chlamydia, or trichomoniasis occur each year. Young adults, population with health inequities and people in resource poor settings bear the significant proportion of sexually transmitted infections (STI). Therefore, rapid, inexpensive and acceptable tests are needed to address STIs in developing countries. PCR based tests are recommended for diagnosis of several STIs, but such tests require sophisticated infrastructure, need to be imported and hence cannot be used in resource limited settings. Affordability can be countered by the development of in house diagnostic assays which are practical and easy to use, and produced within country to further lower the cost.

 Methods Endocervical swabs were collected from patients visiting gynaecology department of hospitals in Delhi. In-house PCR based assay was developed for C. trachomatis, N. gonorrhoeae and T. vaginalis and modified to visual assay using molecular beacon for end-point detection.

Results The molecular beacon based PCR assay was developed for C. trachomatis, N. gonorrhoeae and T. vaginalis and evaluated against different commercial kits viz; Roche AMPLICOR NG/CT kit and qPCR kit of Abbott and fast-track diagnostics. Specificity of molecular beacon was confirmed by competition experiments. Diagnostic tests were more than 95% specific and 99.0% sensitive for all the three pathogens and negative and positive predicted values were around 98.5% and 97.5%, respectively at 95% CI for these three pathogens. We also observed that dry swab samples gave concordant results with that of wet swabs. Assay reagents were stable for more than 6 months at room temperature. We also report, high rates of co-infection for C. trachomatis + N. gonorrhoeae, C. trachomatis + T. vaginalis, N. gonorrhoeae + T. vaginalis amongst women patients in India.

Conclusions Development of a rapid, sensitive, specific and PCR based visual diagnostic assay, suitable for developing countries will provide a better disease management.