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

Probable - A clinically compatible illness that is either epidemiologically linked to a confirmed case of the same disease or has had contact with the same common source as a confirmed case – ie, is part of a common-source outbreak.

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.

Note: Asymptomatic people with laboratory confirmation should be recorded under this category.

For more information refer to the Verocytotoxin- or Shiga toxin-producing Escherichia coli (VTEC/STEC) section of the Communicable Disease Control Manual.