African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5233

Full Length Research Paper

An appropriate method for rapid diagnosis of pulmonary tuberculosis in the clinical laboratories: Staining or polymerase chain reaction (PCR)?

Maryam Pourhajibagher1,2* and Mohtaram Nasrollahi3
1Department of Medical Microbiology, Faculty of Medicine, Mazandaran University of Medical Sciences, Iran. 2Member of Young Researchers and Elite Club, Tehran, Iran. 3Department of Medical Microbiology, Faculty of Medicine, Mazandaran University of Medical Sciences, Iran
Email: [email protected]

  •  Accepted: 05 November 2012
  •  Published: 05 February 2013

Abstract

Rapid diagnosis of pulmonary tuberculosis is crucial to reduce morbidity and mortality from untreated tuberculosis. Because the differential diagnosis of exudative pleural effusion is broad, the rapid diagnosis of tuberculosis pleural effusion would greatly facilitate the management of these patients. This experiment was aimed to determine the best method for early and rapid diagnosis of Mycobacterium tuberculosis among three kinds of staining methods: Fluorochrome, Ziehl Neelsen, Tan Thiam Hok and polymerase chain reaction (PCR). 115 sputum specimens from patients with clinical suspicion of tuberculosis were collected and examined with three methods of staining and PCR. We compared the sensitivity, specificity, the positive and negative predictive value of them and used the culture on Lowenstein-Jensen media as the gold standard. 17 of 115 sputum (14.7%) were positive for culture. The sensitivity of Tan Thiam Hok, Ziehl Neelsen, Fluorochrome and PCR were 100, 85, 100 and 100% and the specificity were 95.3, 100, 99 and 98.03 and the positive predictive value were 70.5, 100, 94.1 and 88.2% and the negative predictive value were 100, 97.02, 100 and 100% respectively. The use of stained-sputum microscopy for acid-fast bacilli (AFB) still remains the most available, easy to perform, inexpensive, and rapid diagnostic test for tuberculosis. Therefore, we must choose the best method that can be done in all clinical laboratories with the lowest time, highest sensitivity and severity mycobacteria. Although fluorochrome gave the highest sensitivity, it needs special expensive equipment, so Ziehl Neelsen is an appropriate method for detecting AFB in sputum microscopically.

 

Key words: Pulmonary tuberculosis, Tan Thiam Hok staining, Ziehl Neelsen staining, flurochrome staining, PCR