WHO: Case definition
WHO case definitions for human infections with influenza A(H5N1) virus
(29 August 2006)
Prompt and accurate reporting of H5N1 influenza cases to WHO is the cornerstone for monitoring both the global evolution of this disease and the corresponding risk that a pandemic virus might emerge. In collaboration with several partners, WHO has developed standardized case definitions to facilitate:
1. Reporting and classification of human cases of H5N1 infection by national and international health authorities.
2. Standardization of language for communication purposes.
3. Comparability of data across time and geographical areas.