Encapsulated, gram-negative diplococci.
Normal flora - humans are the reservoir.
Quadrivalent vaccine prevents disease by serogroups A/C/W-135/Y.
Occurs in outbreaks, particularly in crowded settings.
Colonizer and cause of invasive disease:
Generally of little significance when cultured from nonsterile sites (e.g. genital, pharynx).
Contact and droplet precautions until 24 hours of appropriate antimicrobial therapy.
Prophylaxis may be required for close contacts and healthcare workers.