Conventional versus molecular detection of Chlamydia trachomatis and Neisseria gonorrhoeae among males in a sexually transmitted infections clinic
- Author:
Siti Fazilah Situ
;
Chuan Hun Ding
;
Ramliza Ramli
- Publication Type:Journal Article
- Keywords:
Chlamydia trachomatis, Neisseria gonorrhoeae, sexually transmitted infection, Xpert
- From:The Malaysian Journal of Pathology
2017;39(1):25-31
- CountryMalaysia
- Language:English
-
Abstract:
Chlamydia trachomatis and Neisseria gonorrhoeae are important bacterial pathogens
of sexually transmitted infections (STIs) worldwide. This study sought to compare the analytical
sensitivity and specificity of conventional methods against a rapid molecular method in detecting
STIs caused by these bacteria. Methods: Ninety five first-time male attendees of the Genito-urinary
Medicine Clinic in Hospital Kuala Lumpur were included in this cross-sectional study. The detection
of C. trachomatis was achieved through direct fluorescence antibody (DFA) staining of urethral
swabs and real-time polymerase chain reaction testing (Xpert® CT/NG assay) on urine specimens.
N. gonorrhoeae was detected through Gram staining and culture of urethral swabs and Xpert® CT/
NG assay on urine specimens. Results: From the Xpert® CT/NG results, 11 (11.6%) attendees had
chlamydia, 23 (24.2%) had gonorrhoea and 8 (8.4%) had both STIs. The sensitivity and specificity
of DFA in detecting chlamydia compared to Xpert® CT/NG were 5.3% (95% CI: 0-28) and 94.7%
(95% CI: 86-98), respectively. For gonorrhoea, the sensitivity and specificity of Gram staining were
90.3% (95% CI: 73-98) and 95.3% (86-99), respectively, whereas the sensitivity and specificity of
culture compared to Xpert® CT/NG were 32.2% (95% CI: 17-51) and 100% (95% CI: 93-100),
respectively. Conclusion: Although Gram-stained urethral swab smears are sensitive enough to be
retained as a screening tool for gonorrhoea, culture as well as DFA lack sensitivity and are poorly
suited to screen for gonorrhoea and chlamydia, respectively. However, owing to their high specificity,
conventional detection methods are still suitable as confirmatory tests for gonorrhoea and chlamydia.
- Full text:P020170515570461504080.pdf
