Welcome to the Zoonotic Influenza A Virus Outbreak Toolbox

Key reference documents

Case definitions

WHO suggested outbreak case definition

When there is human exposure to an identified outbreak of an influenza A virus in domestic poultry, wild birds, or other animals; or when there has been an identified human case of novel influenza A virus infection; enhanced surveillance in potentially exposed human populations becomes necessary. The following case definitions are proposed for further adaptation for this purpose:

A person with acute onset of at least one of the following symptoms: cough, sore throat, shortness of breath or coryza...

AND/OR fever

AND with onset within the last 10 days in a person with at least one of the following epidemiological exposures in the two weeks prior to symptom onset in [Area X] since/during [date Y/date Y to Z]:¹

• exposure to animals (including sick or dead animals) or their remains or to environments contaminated by their excreta (faeces, blood, respiratory tract secretions, etc.) in an area where there has been an outbreak of an influenza A virus in domestic poultry, wild birds or other animals in the past two weeks, or
• consumption of raw or undercooked animal products in an area where influenza infections in animals or humans (other than seasonal influenza virus subtypes) have been suspected or confirmed in the past two weeks, or
• close contact (within 1 metre) with an animal or human confirmed to be infected with a zoonotic n influenza A virus. 

_{1. An infection is considered recent if it has been confirmed by positive results from polymerase chain reaction (PCR), virus isolation, or paired acute and convalescent serologic tests. An antibody titre in a single serum is often not enough to confirm a recent infection and should be assessed by reference to valid WHO case definitions for human infections with specific influenza A subtypes. Evidence of illness is not required.} 

_{2. This confirmed case definition is also to be used for official reporting purposes.} 

Data collection tools

• Case investigation forms: PDF | Word
• Line list: Not available. 
• Electronic tools: Not available.

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Laboratory confirmation

Specimen collection procedures Protocol to investigate non-seasonal influenza and other emerging acute respiratory diseases (Geneva: World Health Organization; 2018).

• Laboratory algorithm if influenza is suspected in the event – Figure 1
• Type of specimens for testing for the presence of respiratory pathogens and advice on handling – Table 1

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Response tools and resources

• Protocol to investigate non-seasonal influenza and other emerging acute respiratory diseases (Geneva: World Health Organization; 2018).

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Other resources