Abstract

Culture of Mycobacterium tuberculosis is the gold standard for diagnosis of tuberculosis (TB) that is a much more sensitive test than smear examination. There is a need to use the new methods in order for fast diagnostic way. The aim of this research was to compare microscopic observation drug susceptibility culture with Ziehl-Neelsen stain and Lowenstein-Jensen culture of sputum. Therefore, a diagnostic test was designed. If the patient's history revealed clinical criteria compatible with tuberculosis and the infectious specialist judgment was that of "TB" suspected case, the patient was considered as a pulmonary TB suspect. We did sputum Ziehl-Neelsen stain, culture in Lowenstein-Jensen and MODS media. 100 patients with mean of 52.9 ± 21.83 were evaluated. 40% of patients revealed positive Ziehl-Neelsen stain while 30 and 47% showed positive results in Lowenstein-Jensen and MODS media respectively. In comparison with sputum smear and Lowenstein-Jensen culture, MODS had sensitivity of 82.5 and 86%, specificity of 77 and 70%, positive predictive value of 70 and 55%, negative predictive value of 86 and 92%, respectively. MODS culture demonstrated faster recovery and higher negative predictive value. Therefore, it could be a simple and rapid method in diagnosis of pulmonary tuberculosis.

Key words: Tuberculosis, Ziehl-Neelsen stain, Lowenstein-Jensen culture, sensitivity.