Overview

Light-emitting diodes (LED) have been developed to offer the benefits of fluorescence microscopy without the associated costs. In 2009, the evidence for the efficacy of LED microscopy was assessed by the World Health Organization, on the basis of standards appropriate for evaluating both the accuracy and the effect of new TB diagnostics on patients and public health.

The results showed that the accuracy of LED microscopy was equivalent to that of international reference standards, it was more sensitive than conventional Ziehl-Neelsen microscopy and it had qualitative, operational and cost advantages over both conventional fluorescence and Ziehl-Neelsen microscopy.

On the basis of these findings, WHO recommends that conventional fluorescence microscopy be replaced by LED microscopy, and that LED microscopy be phased in as an alternative for conventional Ziehl-Neelsen light microscopy.

Contents

• Abbreviations
• Executive summary
• 1. Background
• 2. Evidence for policy formulation
  • 2.1 Synthesis of evidence
  • 2.2 Management of declarations of interest
• 3. Summary of results
• 4. Policy recommendations
• 5. Intended audience
• 6 References
• Annexes
  • Annex 1 Expert Group Members
  • Annex 2 WHO staff members
  • Annex 3 STAG-TB members

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