Meningococcal Meningitis
Meningitis caused by Neisseria meningitidis, a gram negative diplococcus. It can cause explosive, rapidly fatal disease within hours of symptom onset.
It also has outbreak potential, particularly within the "meningitis belt" of sub-Saharan Africa. Large epidemics have historically occurred there, predominantly with serogroup A, though the epidemiology has shifted with vaccination programs.
Serogroups A, B, C, W, and Y account for the large majority of invasive disease globally, with regional variation in the dominant serogroup.
Follows the general meningitis pattern detailed in that entry, with one specific and important additional feature. Meningococcal disease frequently presents with, or rapidly progresses to, meningococcemia.
Meningococcemia is a bloodstream infection causing a characteristic non-blanching petechial or purpuric rash (test with a glass tumbler, a true non-blanching rash does not fade under pressure). It can evolve rapidly from a few scattered petechiae to widespread purpura fulminans.
Meningococcal septic shock, with or without overt meningitis, is a distinct and even more rapidly fatal presentation. It features hypotension, poor peripheral perfusion, and disseminated intravascular coagulation. It can occur without significant meningeal signs, particularly in young children.
Waterhouse-Friderichsen syndrome (bilateral adrenal hemorrhage causing acute adrenal insufficiency superimposed on septic shock) is a recognized, catastrophic complication.
The presence of a non-blanching rash in a febrile, unwell patient should prompt immediate empirical antibiotic treatment before any further diagnostic workup, given the speed of potential deterioration. Diagnostic confirmation should never delay treatment in this scenario.
Once treatment is initiated, blood cultures, CSF analysis and PCR of blood or CSF confirm the diagnosis and serogroup. Lumbar puncture is performed where safe to perform (see Meningitis entry for specific contraindications and timing considerations). PCR is particularly valuable where antibiotics have already been given and culture yield may be reduced.
- Immediate IM or IV benzylpenicillin (or, if unavailable, ceftriaxone) should be given in the pre-hospital or primary care setting on clinical suspicion of meningococcal disease, without waiting for hospital transfer. Even a short delay reduction carries mortality benefit.
- In hospital, empirical treatment follows the general bacterial meningitis approach detailed in the Meningitis entry (typically IV ceftriaxone 2 g bd). Continue and rationalize once meningococcus is confirmed and sensitivities (where relevant, though resistance remains uncommon) are available.
- Septic shock or meningococcemia requires the full sepsis and septic shock resuscitation approach detailed in those entries: aggressive fluid resuscitation, vasopressor support as needed, and consideration of corticosteroid therapy for refractory shock.
- Also correct the coagulopathy that frequently accompanies severe meningococcal sepsis.
- Chemoprophylaxis for close contacts is essential given the risk of secondary cases: ciprofloxacin 500 mg PO as a single dose (adults; weight-based dosing in children) is commonly used.
- Alternatives are rifampicin (600 mg PO bd for 2 days in adults, weight-based in children) or ceftriaxone (single IM dose), particularly in pregnancy where ciprofloxacin and rifampicin carry specific considerations.
- Public health notification is mandatory given the outbreak potential, with contact tracing and, in outbreak settings, mass vaccination campaigns using the relevant serogroup-specific vaccine.
- Vaccination: conjugate meningococcal vaccines (covering various combinations of serogroups A, C, W, Y, and, separately, a specific serogroup B vaccine) form part of many routine national immunization schedules.
- Post-exposure vaccination of close contacts may be considered in addition to chemoprophylaxis, depending on the specific serogroup and local protocol.
Referral: this is a maximum medical emergency requiring immediate treatment, ICU involvement for shock or significant compromise, and public health notification for contact tracing and prophylaxis coordination.
