Transmitted in airborne respiratory droplets.
Within the host, pili and other adhesins promote adherence to the pharynx; from here, N. meningitidis can enter the bloodstream.
Individuals with complement deficiencies are especially at risk for meningococcal disease.
Some people are chronic carriers that can spread infection to others.
Meningococcal diseases are largely preventable with vaccines.
Infections can be treated with Cephalosporin or Penicillin G.
Infections
Meningitis:
Inflammation of the meninges that cover the brain and/or spinal cord.
Neisseria meningitidis is the most common cause of meningitis in individuals ages 2-18;
Streptococci pneumoniae is also major cause of bacterial meningitis in this age group.
Patients have fever, stick neck, headache, and increased neutrophils in their cerebrospinal fluid.
Meningococcemia:
Can occur with or without meningitis.
Characterized by fever, headache, nausea, vomiting, and chills.
Skin lesions typically begin as small petechiae-like spots that can coalesce into larger hemorrhagic areas; vascular damage can lead to gangrene.
Musculoskeletal pain, particularly of the joints, is common.
In severe cases,
adrenal gland hemorrhage (aka, Waterhouse-Friderichsen syndrome) and thrombosis with vessel and organ damage can be fatal.
Pneumonia, particularly in older adults.
