Neisseria meningitidis

Background

Microbiology

• Gram-negative diplococcus
• Traditionally organized by serogroups of capsular polysaccharide
  • A, B, C, E, H, I/K, L/ W, X, Y, and Z are confirmed genetically

Epidemiology

• Six serogroups cause essentially all disease: A, B, C, W, X, and Y
• In Canada, serogroups B, C, W-135 and Y are the most common causes, with B being the most commonly reported
  • Historically, B caused the majority of sporadic cases, and virulent serogroup C caused the majority of outbreaks
• In African meningitis belt, serogroups A, C, W-135, and X are most common

Risk Factors

• Living in African meningitis belt during an epidemic
• Participating in Hajj pilgrimage
• Living in student dormitories
• Living in military barracks

Clinical Manifestations

• Causes bacterial meningitis
• May have petechial or purpuric rash

Management

• For meningitis: ceftriaxone 2 g IV q12h or penicillin G for 7 days (5 days in UK)
  • Alternatives include chloramphenicol, aztreonam, and meropenem

Prevention

• Chemoprophylaxis of high-risk contacts is indicated to prevent disease
• Close contacts include living in same household, kissing, or being exposed during resuscitation within 7 days
• Treat with ciprofloxacin one dose, within 24 hours of exposure