Evaluation of a locally developed direct immunofluorescence test for chlamydial infections

The high cost of diagnostic tests for chlamydial infections limits their use which may result in under estimation of the incidence of chlamydial infections. This study was an attempt to reduce the cost of the test by developing an immunofluorescence test for C. trachomatis using monoclonal antibody to major outer membrane protein of C. trachomatis. Urethral swabs were obtained from patients with symptoms of urethritis. The developed immunofluorescence test was compared with culture method and a commercial immunofluorescence test kit (BioMerieux). Compared with the culture method, the sensitivity, specificity, predictive value of positive and predictive value of negative of the developed test were 79, 85, 61 and 93 per cent respectively. The results obtained from the comparison with commercial test kit showed an agreement of 88 per cent. The developed test was positive in 32 per cent of specimens while the commercial test was positive in 24 per cent. The commercial test kit showed excellent reactions and it contained monoclonal antibody to lipopolysaccharide of Chlamydiae in addition to monoclonal antibody to major outer membrane protein which can lead to stronger immunofluorescence staining. The locally developed test, however, costs much less without compromising the results.