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
ReportingBoth confirmed cases and probable cases should be notified.
Confirmed caseA confirmed case requires either:
1. laboratory definitive evidence
2. clinical evidence AND epidemiological evidence.
Laboratory definitive evidenceAt least one of the following:
1. Isolation of measles virus
2. Detection of measles virus by nucleic acid testing
3. Detection of measles virus antigen
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).
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 evidenceAn illness characterised by all of the following:
1. A generalised maculopapular rash lasting three or more days
2. Fever (at least 38° C if measured) at the time of rash onset
3. Cough OR coryza OR conjunctivitis OR Koplik spots.
Epidemiological evidenceAn 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)
b. the other has an illness that starts within seven to 18 (usually 10) days after this contact
2. At least one case in the chain of epidemiologically linked cases (which may involve many cases) is laboratory confirmed.
Probable caseA probable case requires Laboratory suggestive evidence AND clinical evidence.
Laboratory suggestive evidenceDetection 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 evidenceAs with confirmed case.