Comparison of Gabbet's staining, Ziehl–Neelsen staining with fluorescent microscopy for diagnosis of pulmonary tuberculosis: A cross-sectional study

Abstract

Background: Sputum staining for acid-fast bacilli and microscopic examination methods are more sensitive and specific, less time consuming, low cost than other methods for the diagnosis of pulmonary tuberculosis (TB). Methods: In this cross-sectional study conducted over 1-year (n = 109), the sensitivity, specificity and cost-effectiveness of Gabbet's staining, Ziehl–Neelsen (Z-N) staining for the diagnosis of pulmonary TB were studied considering with fluorescence staining method as the gold standard. Results: Majority of the patients belonged to the age group between 21 and 40 years (45.5%). With fluorescence staining, it was found that 25 of the 44 positive smears were of good quality, 12 were of average quality and 7 had poor quality. With Z-N staining, 9/29 of the positive smears were of good quality, 10 were of average quality and poor quality each. With Gabbet's staining, 12 of the 33 positive smears were of good quality, 14 were of average quality and 7 were of poor quality. The sensitivity of the Gabbet's staining (75%) was found to be greater than the Z-N staining (65.9%) considering fluorescence staining as the gold standard. Conclusions: Gabbet's staining can be used as an effective alternative to Z-N staining in low resource settings.

Keywords

• acid-fast bacilli
• diagnosis
• fluorescence microscopy
• gabbet's staining
• pulmonary
• staining
• tuberculosis
• ziehl–neelsen method