Gonococcal antigen detection by Immunochromatographic assay: A reliable and point-of-care diagnostic test for gonorrhoea

Objective: The study was carried out to assess the reliability of Immunochromatographic test for gonococcal antigen in urethral swabs from suspected male patients to validate it as rapid and point-of-care test for gonorrhoea. Methodology: A total of 80 clinically suspected cases of gonorrhoea in mates of different age groups attending at the Skin and VD out patient department of Rajshahi Medical College Hospital (RMCH), Bangladesh during January to December, 2007 were enrolled. Urethral and/or prostatic secretions were collected aseptically for bacterial culture in Chocolate agar media, Gram-stained smear microscopy for gram-negative diplococci and rapid test by Immunochromatographic assay. Results: Out of 80 samples, culture yielded growth of Neisseria gonorrhoeae in 47 (58.75%) cases, and microscopy revealed gram-negative diplococci in 45(56.25%) cases. Immunochromatographic test was performed by following manufacturer's instructions in randomly selected 50 cases including 38 urethral swabs and 12 prostatic secretions with 35 cases found positive against 36 of those culture-positive cases. Considering culture as gold standard of diagnosis, sensitivity, specificity, positive and negative predictive values of Immunochromatographic test were calculated as 97.22% (95% CI 83-99%), 100% (95% CI 73-100%), 100%, and 93.33% respectively. Conclusion: This limited study reinforces that detection of gonococcal antigen by Immunochromatographic assay is a rapid, easy to perform and reliable diagnostic tool for early detection of acute male gonorrhoea with high sensitivity and specificity. It may be a useful test for screening clinically suspected case of gonococcal infections in male, particularly suitable as point-of-care test.