The clinical case definition of diphtheria is

An upper respiratory tract illness characterized by sore throat, low-grade fever, and an adherent membrane of the tonsil(s), pharynx, and/or nose.

Laboratory criteria for diagnosis

• Isolation of Corynebacterium diphtheriae from a clinical specimen, or
• Histopathologic diagnosis of diphtheria

Case classification

Probable: a clinically compatible case that is not laboratory confirmed and is not epidemiologically linked to a laboratory-confirmed case

Confirmed: a clinically compatible case that is either laboratory confirmed or epidemiologically linked to a laboratory-confirmed case Comment

From the CDC guidelines: Cutaneous diphtheria should not be reported. Respiratory disease caused by nontoxigenic C. diphtheriae should be reported as diphtheria. All diphtheria isolates, regardless of association with disease, should be sent to the Diphtheria Laboratory, National Center for Infectious Diseases, CDC.

---

The first version of this article was adapted from the CDC document "Diphtheria - 1995 Case Definition" at http://www.cdc.gov/epo/dphsi/casedef/diphtheria_current.htm

as a work of an agency of the U.S. Government without any other copyright notice it should be available as a public domain resource