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NOTE: A surveillance case definition is a set of uniform criteria used to define a disease for public health surveillance. Surveillance case definitions enable public health officials to classify and count cases consistently across reporting jurisdictions. Surveillance case definitions are not intended to be used by healthcare providers for making a clinical diagnosis or determining how to meet an individual patient’s health needs.

Clinical Criteria

An illness with all of the following characteristics:

  • Acute onset of generalized maculopapular rash
  • Temperature greater than 37.2°C ( greater than 99°F), if measured
  • Arthralgia/arthritis, or lymphadenopathy, or conjunctivitis

Cases meeting the measles case definition are excluded. Also excluded are cases with serology compatible with recent measles virus infection.

Laboratory Criteria For Diagnosis

  • Isolation of rubella virus, OR
  • Significant rise in rubella antibody level by any standard serologic assay, OR
  • Positive serologic test for rubella immunoglobulin M (IgM) antibody

Case Classification


Any generalized rash illness of acute onset


A case that meets the clinical case definition, has no or noncontributory serologic or virologic testing, and is not epidemiologically linked to a laboratory-confirmed case


A case that is laboratory confirmed or that meets the clinical case definition and is epidemiologically linked to a laboratory-confirmed case

Related Case Definition(s)