Under investigation - A case which has been notified but information is not yet available to classify it as probable or confirmed.

Probable - A probable case of non seasonal influenza A (H1N1)* virus infection is defined as a person with an influenza-like illness** who has a strong epidemiological link to a confirmed case or defined cluster.

Confirmed - A confirmed case of non seasonal influenza A (H1N1)* virus infection is defined as a person with laboratory confirmed non seasonal influenza A (H1N1)* virus infection by one or more of the following tests:

• Real-time RT-PCR
• Viral culture
• Four-fold rise in swine influenza A(H1N1) virus specific neutralising antibodies

Not a Case - A case that has been investigated, and subsequently has been shown not to meet the case definition

*also termed novel influenza A H1N1 or influenza A (H1N1) 09
**influenza-like illness is defined as:
(i) history of fever, chills and sweating OR documented fever >37.8°C
AND
(ii) cough OR sore throat

Close contact Close contact is defined as having cared for, lived with, or had direct contact with respiratory secretions or bodily fluids of a probable or confirmed case

Note: The case status definition changed on 22 June 2009 to coincide with the move to pandemic ‘management’ phase. The ‘suspect’ case definition is no longer available. Although the ‘suspect’ case status option has been disabled, users are still able to change the case status of ‘suspect’ cases to either ‘probable’, ‘confirmed’, or ’not a case’ after 22 June 2009.

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