The bleach microscopy method and case detection for tuberculosis control.

The World Health Organization (WHO) and the International Union Against Tuberculosis and Lung Disease (The Union) recommend direct sputum smear microscopy for tuberculosis (TB) case finding in resource-poor settings. This method is associated with poor sensitivity. Digestion of sputum with bleach prior to smear preparation has been reported to increase sensitivity. Some workers, having reviewed the relevant literature, have called for the WHO and The Union to advocate for a shift to this methodology for TB case finding. This article highlights deficiencies in the scope and detail of available evidence, and cautions against the premature, and possibly counter-productive, adoption of so-called 'bleach microscopy'. Further well-guided research is required to answer policy-relevant gaps in our knowledge about this promising technology.