RAPID DIAGNOSIS OF TUBERCULOSIS IN CHILDREN BY USING AMPLIFIED POLYMERASE CHAIN REACTION

Abstract

Tuberculosis has reemerged as a major world wide public health problem with increasing incidence among adults and children. the present work is conducted to evaluate the rapid detection and identification of mycobacterium tuberculosis by polymerase chain reaction method in comparison to the microscopic and cultural methods of diagnosis of pulmonary tuberculosis in children. This work was carried out on 40 cases (25 females and 15 males) with clinical suspicion of pulmonary tuberculosis and their ages ranged from 6-14 years with a mean age of 11.4 ± 2 years. Sputum samples were collected from all cases. All samples were examined for the presence of AFB in direct smear by microscopic examination by Z.N. stain and culture on L.J. medium for detection of mycobacterium tuberculosis. In addition to the species-specific PCR using the primer that amplify 245bDNA from encoding gene IS6110. Among 40 sputum samples, 17 positive cases for AFB were found, 26 gave growth on L.J. medium and 25 were PCR positive. When comparing the results of positive smears and species-specific PCR with positive culture techniques of sputum specimens, the following was noticed. The sensitivity of positive smear and species-specific PCR was 65% and 96% respectively, while the specificity was I 00% for both.