Comparative study of culture, direct immunofluorescent antibody test and enzyme immunoassay for the diagnosis of urogenital infections caused by Chlamydia trachomatis.

We studied three population groups (161 symptomatic female, 62 asymptomatic female and 74 symptomatic male) to determine the prevalence of genital tract infections caused by Chlamydia trachomatis in Kuwait. Three techniques, viz. tissue culture, direct immunofluorescent antibody test (MicroTrak) and enzyme immunoassay (Chlamydiazyme) were employed for the detection of C. trachomatis. The overall positivity based on positive tissue culture in symptomatic cases was 16.2% (17.4% in female and 13.5% in male). The two rapid methods for antigen detection were compared with tissue culture. Based on a positivity criterion of greater than 10 elementary bodies in the direct immunofluorescent antibody assay, sensitivity and specificity of the test were 66.7% and 97.2% while the positive and negative predictive values were 77.8% and 97.2% respectively. The sensitivity and specificity of the enzyme immunoassay were 61.3% and 96.7% with positive and negative predictive values of 80.8% and 94.6% respectively. There was an agreement of 92.0% between the three tests. The two rapid antigen detection tests seem to be similar and provide an alternative for diagnosing Chlamydia trachomatis in our patients.