Under investigation - a person with a Severe Acute Respiratory Infection (SARI) AND with one or more of the following exposures during the two weeks prior to the onset of symptoms:

• Travel to a country where human cases of H7N9 influenza have recently been reported, especially if there was recent direct or close contact with animals (e.g. wild birds, poultry or pigs).
• Close contact with a laboratory-confirmed case.

Probable - a person fitting the definition of a suspect case but with no possibility of laboratory confirmation for H7N9 influenza, either because the patient or samples are not available for testing AND not already explained by any other infection or aetiology, including all clinically indicated tests for community acquired pneumonia according to local management guidelines.

Confirmed - a person with laboratory confirmation of infection with H7N9 influenza by a person with laboratory confirmation of infection with H7N9 influenza at the WHO National Influenza Centre (ESR, NCBID).

Notes
SARI: an acute respiratory illness with a history of fever or measured fever of = 38°C, AND cough, AND onset within the past two weeks, AND requiring inpatient hospitalisation (defined as a patient who is admitted under a medical team and to a hospital ward or assessment unit).

Travel: currently, China (excluding Hong Kong) is the only country that has recently reported human cases of H7N9 influenza.

Close contacts include:

• any person who provided care for the patient or who had other similarly close physical contact in the two weeks before symptom onset; this includes health care workers or family members
• any person who stayed in the same place (e.g. household, office) as a probable or confirmed case while the case was symptomatic.

For more information refer to the Non-seasonal influenza section of the Communicable Disease Control Manual.