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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 characterized by all of the following clinical features:

  • A generalized rash lasting greater than or equal to 3 days
  • A temperature greater than or equal to 38.3°C (101°F)
  • Cough, or coryza, or conjunctivitis

Laboratory Criteria For Diagnosis

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

Case Classification


Any rash illness with fever


Meets the clinical case definition, has no or noncontributory serologic or virologic testing, and is not epidemiologically linked to a probable or confirmed case


A case that is laboratory confirmed or that meets the clinical case definition and is epidemiologically linked to a confirmed or probable case. A laboratory-confirmed case does not need to meet the clinical case definition.


Two probable cases that are epidemiologically linked would be considered confirmed, even in the absence of laboratory confirmation. Only confirmed cases should be reported to the National Notifiable Diseases Surveillance System (NNDSS).

Related Case Definition(s)