NEISSERIA MENINGITIDIS

I. Pathophysiology

  1. Most common serogroups in human infections: A, B, C, Y, W-135
  2. Infection is associated with a 10% fatality rate
  3. Highly contagious

II. Clinical Features and epidemiology

  1. Tends to cause acute bacterial meningitis and/or septicemia
  2. Rapidly progressive-Sometimes only a few hours between initial presentation and sepsis
  3. Mortality is 10-15% even with antibiotic treatment, and survivors often have significant morbidity
  4. In a retrospective study in children < 16yo with confirmed menningococcal disease, mean time to advanced disease stages (neck stiffness, unconsciousness, or seizures) was < 24h for 5-15yo and even faster for younger children; presented with septicemia in 66% and meningitis in 22%; some had rash other than classic purpural rash or even no rash (Lancet 367:397, 2006--JW)
  5. As of 2011, around 3,000 cases/year in U.S.; most in children < 2yo.

III. Vaccination:

  1. Polysaccharide meningoccal vaccine aka "MPSV4" (Menomune)-Largely supplanted by conjugate vaccine (see below)
    1. Developed in 1970's
    2. Contains capsular polysaccharides of serogroups A, C, Y, and W-135
    3. Provides serologic evidence of immunity for only 3-5y
    4. Single dose of 0.5ml SQ
    5. Recc'd by ACIP for high risk* pts 2-10yo or > 55yo (revaccination recc'd after 2-3y if initial received at < 4yo or after 5y for others)
    6. Immunity probably lasts at least 10y (Med. Lett. 42:69, 2000) but manufacturer recommends revaccination after 3-5y
  2. Conjugate meningococcal vaccine aka "MCV4" (Menactra)
    1. Active against serogroups A, C, Y and W-135
    2. Single dose of 0.5ml IM
    3. Recommended by ACIP for:
      1. All kids at 11-12yo (with booster at age 16; if didn't receive at age 11-12 give at earliest opportunity up to age 18; if got initial dose at 13-15yo, give booster at age 16-18y)
      2. High risk* pts 2-55yo (for kids, give 2-dose primary series, 8wks apart and if remain at high risk, give booster: 3y after primary series if latter received at 2-6yo, else 5y after primary series; if remain at high risk give booster Q5y)-After age 55, MPSV4 (see above) is recommended by ACIP.

*--High risk pts include college freshmen living in dormitories, military recruits, travelers to endemic areas, or pts with terminal complement component deficiencies, anatomic or functional asplenia, or HIV infection

(Sources include Core Content Review of Family Medicine, 2012)