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

Meningococcal disease manifests most commonly as meningitis and/or meningococcemia that may progress rapidly to purpura fulminans, shock, and death. However, other manifestations might be observed.

Laboratory Criteria For Diagnosis

Isolation of Neisseria meningitidis from a normally sterile site (e.g., blood or cerebrospinal fluid [CSF] or, less commonly, joint, pleural, or pericardial fluid)

Case Classification


A case with a positive antigen test in CSF or clinical purpura fulminans in the absence of a positive blood culture


A clinically compatible case that is laboratory confirmed


Positive antigen test results from urine or serum samples are unreliable for diagnosing meningococcal disease.

Related Case Definition(s)

Page last reviewed: April 16, 2021