Comparison of Zeihl-Neelsen and Polymerase Chain Reaction Techniques in diagnosis of Tuberculosis in Khartoum State

Abstract

This study was carried out in Khartoum state during the period between February and August 2011. The main objective was to compare ZN staining method and PCR in diagnosis of tuberculosis. Hundred sputum samples were collected from different TB centers in Khartoum state including Academic Charity Hospital, Abu Anga Hospital, The Reference Tuberculosis Laboratory and Elsha’ab Teaching Hospital. Bacterial DNA was extracted from positive and negative ZN smears using chelex extraction method. PCR technique was performed to detect M. tuberculosis IS6110 gene in these specimens. This study showed result that 35 samples were acid fast bacilli. 32 (91.4%) of ZN stain positive were PCR positive. While 6 (9.2%) of ZN stain negative showed PCR positive. The study concluded that the sensitivity and specificity of ZN stain was poor comparable with those of PCR, which proved to be a better method for diagnosis of the disease.