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Rubella / German Measles
1996 Case Definition

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.