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-42

Case Classification


  • Clinical purpura fulminans in the absence of a positive blood culture; OR
  • Gram-negative diplococci, not yet identified, isolated from a normally sterile body site (e.g., blood or cerebrospinal fluid [CSF]).


  • Detection of N. meningitidis-specific nucleic acid in a specimen obtained from a normally sterile body site (e.g.,. blood or CSF), using a validated polymerase chain reaction (PCR) assay, OR
  • Detection of N. meningitidis antigen:
    • in formalin-fixed tissue by immunohistochemistry (IHC); OR
    • in CSF by latex agglutination.


  • Isolation of Neisseria meningitidis:
    • From a normally sterile body site (e.g., blood or cerebrospinal fluid, or, less commonly, synovial, pleural, or pericardial fluid), OR
    • From purpuric lesions.

Related Case Definition(s)

Page last reviewed: April 16, 2021