There have been few studies evaluating the efficacy of polymerase chain reaction (PCR) testing in Front other routine test for diagnosis of TB in children. The tuberculin skin test (TST) used to detect Mycobacterium tuberculosis infection in children has many drawbacks, and a new diagnostic test for has been introduced. We assessed the diagnostic yield of PCR prospectively in a blinded study of patients referred to Al-Nassyria center for chest diseases and other private laboratories from January to June 2008 and compared the results to the routine TST, smears with Ziehl-Neelsen staining and culture on Lo¨wenstein-Jensen medium which used as the “gold standard.â€. Sputum specimens were collected from 108 TB suspects patients and analyzed for the presence of Mycobacterium tuberculosis..TST yielded 23 (21.3%) were positive for TB with 65.7 % sensitivity and 87% specificity in comparing with 35(32.4%) by culture which improved the presence of 3cases as false-positive and 15 cases as false-negative by TST . All smear positive specimens appeared culture positive, but showed 54.3 %sensitivity and 100 % specificity. PCR amplification results appeared less than culture and more than each of smear and TST with %88.6 sensitivity and 100% specificity .All the thirty one PCR positive samples showed culture positive. It is concluded that although both culture and PCR amplification method are Sensitive and specific for the detection of M. tuberculosis in respiratory specimens of children . Rapid PCR method appeared to be more suitable than other tests especially the routine TST which applied.
