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

Suspect (in children under five years of age) - Any paroxysmal cough with whoop, vomit or apnoea for which there is no other known cause.

Probable - A clinically compatible illness where the cough is lasting longer than two weeks. However in situations where serology has been requested after consultation between the Medical Officer of Health and the local microbiologist, a clinically compatible illness with laboratory suggestive evidence will also be considered as probable.

Confirmed - A clinically compatible illness accompanied by laboratory definitive evidence, or is epidemiologically linked to a confirmed case.

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 Pertussis section of the Communicable Disease Control Manual.