Case Definition

Confirmed case

• Clinical illness with laboratory confirmation of infection by:
  
  
• Detection of influenza-specific RNA by NAT in an appropriate clinical specimen;
  
  OR
  
  

• Isolation of influenza virus from an appropriate clinical specimen;
  
  OR

• Demonstration of influenza virus antigen in an appropriate clinical specimen;
  
  OR
  

• Significant (e.g. fourfold or greater) rise in Influenza antibody titre between acute and convalescent sera.