In the present pilot study, endocervical and urethral swabs collected from 100 patients attending sexually transmitted disease (STD) clinics and regional centre for STD in two referral hospitals in New Delhi were analyzed by enzyme immune assay (EIA), polymerase chain reaction (PCR) and direct fluorescent antibody (DFA) for detection of
C.
trachomatis. It was found that EIA could detect a very low number of cases (3/100) as against DFA (11/100) and PCR (9/100). Thus, in spite of the widespread availability, lower cost and ease of performance of the enzyme-linked-immunosorbent serologic assay, the present study highlights the need to employ sophisticated diagnostic tools like DFA and PCR for detection of
Chlamydia trachomatis
in STD patients.