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.
An illness of variable severity characterized by diarrhea, fever, nausea, cramps, and tenesmus. Asymptomatic infections may occur.
Laboratory Criteria for Diagnosis
Isolation of Shigella from a clinical specimen
A clinically compatible case that is epidemiologically linked to a confirmed case
A case that is laboratory confirmed
Laboratory-confirmed isolates are reported to CDC via the Public Health Laboratory Information System (PHLIS), which is managed by the Foodborne and Diarrheal Diseases Branch, Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, CDC. Both probable and confirmed cases are reported to the National Notifiable Diseases Surveillance System, but only confirmed cases are reported to PHLIS. Confirmation is based on laboratory findings, and clinical illness is not required.
The 1997 case definition appearing on this page was previously published in the 1990 MMWR Recommendations and Reports titled Case Definitions for Public Health Surveillance.1 Thus, the 1990 and 1997 versions of the case definition are identical.