Comparative study of Ziehl Neelsen and Auramine-O staining methods for the detection of Mycobacterium tuberculosis in sputum

Abstract

This study cross sectional study was designed to compare the performance of Ziehl Neelsen staining and Auramine fluorescent microscopy staining techniques in detecting the presence of Mycobacterium tuberculosis in sputum. Sputum specimens were collected in screw-capped plastic bottles. Un-concentrated and concentrated sputum specimens were stained using Ziehl Neelsen and Auramine-O technique in both cases. The stained smears were examined for the presence of Mycobacterium tuberculosis. Chi-square test was used to show whether there was a relationship or no relationship. Descriptive statistics were used to present the data inform of tables. The findings showed that both Ziehl Neelsen and Auramine-O preparations each showed 5.6% of positive cases and there was a significant relationship between both techniques (P=0.0000). However, 20% of cases showed false positive with Ziehl Neelsen concentrate technique and 30% showed false positive with Auramine-O concentrate preparation. There was a significant relationships in the performance of Ziehl Neelsen and Auramine-O techniques in the detection of AFB, although Auramine-O showed a greater false positive than Ziehl Neelsen method in the detection of AFB (P= 0.0000). Both Ziehl Neelsen and Auramine-O techniques can be used in the detection of AFB in this study population. However, Auramine-O technique should remain a method of choice in this study population whenever dealing with few samples because it showed a greater sensitivity than Ziehl Neelsen method in the detection of AFB.