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

Probable - A clinically compatible illness.

Confirmed - A clinically compatible illness that is laboratory confirmed.

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

For more information refer to the Neisseria meningitidis invasive disease section of the Communicable Disease Control Manual.