Clinical illness and laboratory confirmation of infection in the absence of recent immunization with mumps-containing vaccine (i.e., within the previous 28 days):
- Isolation of mumps virus from an appropriate clinical specimen OR
- Detection of mumps virus RNA OR
- Significant (e.g. fourfold or greater) rise or seroconversion in serum mumps IgG titre by any standard serologic assay between acute and convalescent sera OR
- Positive serologic test for IgM antibody in a person who is epidemiologically linked to a laboratory-confirmed case or has recently travelled to an area of known mumps activity
Clinical illness in a person with an epidemiologic link to a laboratory-confirmed case
Mumps-compatible illness in the absence of a laboratory confirmation of infection and not epidemiologically linked to a laboratory-confirmed case.
Illness that could be mumps but without parotitis or orchitis, in a person who is a contact of a confirmed or clinical mumps case.
Clinical illness is characterized by acute onset of unilateral or bilateral tender, self-limited swelling of the parotid or other salivary gland, or orchitis lasting two or more 2 days, and without other apparent cause.
IgM serology has the potential for false positive and false negative findings.
If the clinical presentation is inconsistent with a diagnosis of mumps or in the absence of recent travel or exposure history, IgM result must be confirmed by the other listed confirmatory methods. In a mumps case that had been previously immunized, the IgM class antibody response may not be detectable.