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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.

CSTE Position Statement(s)

  • 09-ID-05

Case Classification

Probable

In the absence of a more likely diagnosis, an upper respiratory tract illness with:

  • An adherent membrane of the nose, pharynx, tonsils, or larynx; AND
  • Absence of laboratory confirmation; AND
  • Lack of epidemiologic linkage to a laboratory-confirmed case of diphtheria.

Confirmed

An upper respiratory tract illness with an adherent membrane of the nose, pharynx, tonsils, or larynx; and any of the following:

  • Isolation of Corynebacterium diphtheriae from the nose or throat; OR
  • Histopathologic diagnosis of diphtheria; OR
  • Epidemiologic linkage to a laboratory-confirmed case of diphtheria.

Related Case Definition(s)