Comparison of a real-time polymerase chain reaction-based system and Erlich-Ziehl-Neelsen method with culture in the identification of Mycobacterium tuberculosis

Abstract

Basckground/aim: Mycobacterium tuberculosis is still a major health problem throughout the world, especially in developing countries. Disease control heavily depends on the establishment of early diagnosis. The aim of this study is to compare the efficacy of culture, GeneXpert MTB/RIF device, and Erlich-Ziehl-Neelsen direct microscopic method.

Materials and methods: A total of 927 samples (243 respiratory and 684 nonrespiratory), which were sent to Ondokuz Mayıs University Medical Faculty Tuberculosis Laboratory on suspicion of M. tuberculosis, were included in the study.

Results: When compared to standard culture, sensitivity, specificity, and positive and negative predictive values of the GeneXpert system for respiratory samples were 100%, 98.7%, 87%, and 100%, respectively; these values for nonrespiratory samples were 71%, 98.6%, 71%, and 98.6%, respectively.

Conclusion: New, reliable, rapid, and easy-to-use methods that display high specificity and sensitivity are required for an effective struggle against tuberculosis. According to these results, we suggest that GeneXpert MTB/RIF is a rapid and reliable system, and when used in company with conventional tests, it would make significant contributions to the diagnosis of tuberculosis.

Keywords: GeneXpert MTB/RIF; Mycobacterium tuberculosis; culture.