Confirmation of positive acid fast bacilli samples by tuberculosis bacilli culture

Abstract

This study attempts to estimate the efficiency of acid fast bacilli(AFB) stain technique to diagnosis tuberculosis in the different samples. This study was performed in general Al-Diawynia hospital and Department of Microbiology, Medicine College, Al-Qadisiha University between October 2005 to October 2008. A total of 1654 clinical samples from 750 patients analyzed for acid-fast staining. These were 605 sputum, 67 bronchial wash, 42 pleural fluids, 4 urine, 7 ascetic fluids and 3 cerebrospinal fluids. The stained smear-positive were (5.3 %) distributed in different samples .Seventy five patients (10%) were evaluated by Lowenstein-Jensen (LJ) medium culture that it was employed as gold standard for tuberculosis diagnosis, of these 58 were culture-positive specimens. The sensitivity of Ziehl-Neelsen (ZN) stain Methods and LJ culture were (68.9 %) and (95.2 %) respectively. The specificity of ZN stain Methods and LJ culture were (88.2 %) and (45.4 %) respectively. The diagnosis accuracy of ZN stain Methods and LJ culture were (73.3 %) and (73.3 %) respectively. The positive predictive value of ZN stain Methods and LJ culture were (95.2 %) and (68.9 %), while negative predictive value were (45.4 %) and (88.2 %) respectively.