Australian national notifiable diseases case definitions
Measles case definition
This document contains the case definitions for Measles which is nationally notifiable within Australia. This definition should be used to determine whether a case should be notified.
Communicable Diseases Surveillance
Australian national notifiable diseases case definitions - Measles
Reporting
Both confirmed cases and probable cases should be notified.Confirmed case
A confirmed case requires either:1. laboratory definitive evidence
OR
2. clinical evidence AND epidemiological evidence.
Laboratory definitive evidence
At least one of the following:1. Isolation of measles virus
OR
2. Detection of measles virus by nucleic acid testing
OR
3. Detection of measles virus antigen
OR
4. IgG seroconversion or a significant increase in antibody level or a fourfold or greater rise in titre to measles virus EXCEPT if the case has received a measles-containing vaccine eight days to eight weeks before testing. (NOTE: paired sera must be tested in parallel).
OR
5. Detection of measles virus-specific IgM antibody confirmed in an approved reference laboratory EXCEPT if the case has received a measles-containing vaccine eight days to eight weeks before testing.
Clinical evidence
An illness characterised by all of the following:1. A generalised maculopapular rash lasting three or more days
AND
2. Fever (at least 38° C if measured) at the time of rash onset
AND
3. Cough OR coryza OR conjunctivitis OR Koplik spots.
Epidemiological evidence
An epidemiological link is established when there is: 1. Contact between two people involving a plausible mode of transmission at a time when:
a. one of them is likely to be infectious (approximately five days before to four days after rash onset)
AND
b. the other has an illness that starts within seven to 18 (usually 10) days after this contact
AND
2. At least one case in the chain of epidemiologically linked cases (which may involve many cases) is laboratory confirmed.
Probable case
A probable case requires Laboratory suggestive evidence AND clinical evidence.Laboratory suggestive evidence
Detection of measles specific IgM antibody other than by an approved reference laboratory EXCEPT if the case has received a measles-containing vaccine eight days to eight weeks before testing.Clinical evidence
As with confirmed case.
