Comparison Between Conventional methods and Molecular Techniques for Detection of Tuberculosis Microbe in Sputum Specimens

Abstract

Tuberculosis remains a global epidemic, especially in developing countries. Rapid diagnosis of active Mycobacterium tuberculosis infection plays a critical role in controlling the spread of tuberculosis. Conventional methods may take up to several weeks to produce results. The objective of the present study was to compare between conventional and molecular techniques in detection of tuberculosis microbe in sputum specimens. This study was conducted on a total of 100 clinically suspects pulmonary tuberculosis patients. Out of 100 patients, 58 were males and 48 were females. Direct smear examination with Ziehl-Neelsen (ZN) and polymerase chain reaction (PCR) were applied for sputa. Culture on Löwenstein-Jensen medium was used as the “gold standard.” The number of positive cases by three different diagnostic techniques was determined. Out of 100 specimen investigated, 16 was Z-N staining positive, 25 were standard culture positive and 24 were PCR positive. The sensitivity and specificity of PCR using culture method as gold standard were 96.1% and 100% respectively. The sensitivity and specificity of Z-N technique using culture method as gold standard were 64% and 100% respectively. It is concluded that PCR is a rapid, sensitive and specific technique for detectionof tuberculosis microbe in sputum. Further study with large number of specimens is required to validate the results of the present study.