Comparison of Tan Thiam Hok, Ziehl Neelsen and Fluorochrome as Acid-Fast Bacilli Staining Methods in Sputum

Because of its simplicity, rapidity, low cost and relatively sensitive, sputum acid-fast bacilli (AFB) smear microscopy is the primary tool for detecting pulmonary tuberculosis and follow up of therapy. This experiment is aimed to determine the best acid-fast staining method that can be used for routine laboratory examination, especially in the high burdened clinical laboratory. We compared the sensitivity, specivity, and the positive and negative predictive value of 3 kinds of methods : Tan Thiam Hok, Ziehl Neelsen and Fluorochrome, using culture on Lowenstein-Jensen media as the gold standard. The smear results were observed using IUTLD scale. Twenty seven of 98 sputum specimens from 98 patients with clinical suspicion of tuberculosis (27,6 %) were positive by culture. The sensitivity of Tan Thiam Hok, Ziehl Neelsen and Fluorochrome were 62,9%, 81,5% and 92,6%, while the specivity were 92,9%, 91,6% and 91,1% respectively. The positive predictive value were 77,3 %, 78,6 %, 71,4 % , and the negative predictive value were 86,8 %, 92,9 %, 96,8 % respectively. Although fluorochrome gave the highest sensitivity, it needs special expensive equipments. We conclude that Ziehl Neelsen is still the method of choice for detecting AFB in sputum microscopically.