Modified bleach method for detection of acid-fast bacilli in lymph node aspirates and its comparison with the conventional Ziehl-Neelsen stain

Abstract

Background: Microscopy detection of acid-fast bacilli (AFB) by Ziehl-Neelsen (ZN) method is a rapid and feasible method but has low sensitivity. Aims: To evaluate the efficacy of bleach method with cytological diagnosis and the conventional method. Methods: Five hundred and seventy-five patients with tubercular lymphadenitis were evaluated. The acid-fast positivity by routine staining was compared with modified bleach method of AFB staining. Result: Among 575 patients, 230 (40%) were positive for AFB on conventional ZN method, 310 (53.9%) on cytology and the smear positivity was increased to 365 (63.5%) by bleach method. Conclusion: The bleach method is simple and inexpensive. It clearly improves microscopic detection of AFB.

Keywords

• Modified bleach
• tubercular lymphadenitis
• Ziehl-Neelsen method