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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 Description

An illness that has all the following characteristics:

  • Acute onset of generalized maculopapular rash
  • Temperature greater than 99.0°F (greater than 37.2°C), if measured
  • Arthralgia/arthritis, lymphadenopathy, or conjunctivitis

Laboratory Criteria For Diagnosis

  • Isolation of rubella virus, OR
  • Significant rise between acute- and convalescent-phase titers in serum rubella immunoglobulin G 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


Serum rubella IgM test results that are false positives have been reported in persons with other viral infections (e.g., acute infection with Epstein-Barr virus [infectious mononucleosis], recent cytomegalovirus infection, and parvovirus infection) or in the presence of rheumatoid factor. Patients who have laboratory evidence of recent measles infection are excluded.

Related Case Definition(s)