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.

Case Classification


  • Clinical purpura fulminans in the absence of a positive blood culture
  • A clinically compatible case with gram negative diplococci from a normally sterile site (e.g., blood or cerebrospinal fluid [CSF])


  • Evidence of N. meningitidis DNA using a validated polymerase chain reaction (PCR), obtained from a nomally sterile site (e.g., blood or CSF),1
  • Evidence of N. meningitidis antigen by immunohistochemistry (IHC) on formalin-fixed tissue of latex agglutination of CSF*2


A clinically compatible case AND isolation of Neisseria meningitidis from a normally sterile site (e.g., blood or cerebrospinal fluid {CSF} or, less commonly, synovial, pleural, or pericardial fluid) or skin scrapings of purpuric lesions.


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


  1. Mothershed EA, Sacchi CT, Whitney AM, Barnett GA, Ajello GW, Schmink S, Mayer LW, Phelan M, Taylor TH Jr, Bernhardt SA, Rosenstein NE, Popovic T. 2004. Use of real-time PCR to resolve slide agglutination discrepancies in serogroup identification of Neisseria meningitidis. J Clin Microbiol 42:320-328.
  2. Guarner J. Greer PW, Whitney A, Shieh WJ, Fischer M, White EH, Carlone GM, Stephens DS, Popovic T, Zaki SR. Pathogenesis and diagnosis of human meningococcal disease using immunohistochemical and PCR assays; American Journal of Clinical Pathology. 122(5):754-64, 2004 Nov.

Related Case Definition(s)

Page last reviewed: April 16, 2021