Yellow fever case definition

This document contains the case definitions for Yellow fever which is nationally notifiable within Australia. This definition should be used to determine whether a case should be notified.

Communicable Diseases Surveillance

(Effective 1 January 2013)

Reporting

Only a confirmed case should be notified.

Confirmed case

A confirmed case requires either laboratory definitive evidence AND clinical evidence OR laboratory suggestive evidence AND clinical evidence AND epidemiological evidence.

Laboratory definitive evidence

Isolation of yellow fever virus

OR

Detection of yellow fever virus by nucleic acid testing

OR

Seroconversion or a four-fold or greater rise in yellow fever virus-specific serum IgM or IgG levels between acute and convalescent serum samples in the absence of vaccination in the preceding 3 weeks

OR

Detection of yellow fever virus antigen in tissues by immunohistochemistry.

Laboratory suggestive evidence

Yellow fever virus-specific IgM detected in the absence of IgM to other relevant flaviviruses, in the absence of vaccination in the preceding 3 months

Confirmation of laboratory results by a second arbovirus reference laboratory is required in the absence of travel history to areas with known endemic or epidemic activity.

Clinical evidence

A clinically compatible illness.

Epidemiological evidence

History of travel to a yellow fever endemic country in the week preceding the onset of illness.

Yellow fever changes

The yellow fever case definition was changed to exclude vaccine-related cases from being reported.

At the end of laboratory definitive evidence, point 3 'in the absence of vaccination in the preceding 3 weeks' was added.

At the end of laboratory suggestive evidence 'in the absence of vaccination in the preceding 3 months' was added.

A note 'Confirmation of laboratory results by a second arbovirus reference laboratory is required in the absence of travel history to areas with known endemic or epidemic activity' was also added.