Sodium Hypochlorite Sedimentation Technique: A Simple Way to Enhance Sensitivity of Ziehl-Neelsen Stain in Diagnosis of Smear Negative Pulmonary Tuberculosis

Ó Abstract: Background: With the looming global HIV pandemic, the problem of tuberculosis tiptoes as a perpetual companion. Smear negative pulmonary tuberculosis which pose substantially a challenge for diagnosis, hoots this combination into noxious health problem. There is, therefore, an urgent need to establish more sensitive, safe and fairly rapid methodologies that could confirm diagnosis particularly in smear negative pulmonary tuberculosis patients. Aim: This study was carried out to establish whether, 3.5% sodium hypochlorite overnight sedimentation method improves the sensitivity of Ziehl-Neelsen (ZN) stain in samples declared as smear negative. Material and Methods: A total of 605 direct ZN smear negative sputum specimens were examined after concentration with 3.5% sodium hypochlorite overnight sedimentation method. Results: Forty one (6.77%) samples were found to be positive when smears were repeated after performing sodium hypochlorite sedimentation technique. Sensitivity and specificity of this method was found to be 76.31% and 97.88% respectively. Conclusion: 3.5% Sodium hypochlorite sedimentation technique has the potential to improve the diagnosis in tuberculosis in smear negative pulmonary tuberculosis cases especially in resource poor countries.