Description

• Meningococcemia is a blood-borne infection caused by Neisseria meningitidis.
• Bacteremia without meningitis: Patient is acutely ill and may have skin manifestations (rashes, petechiae, and ecchymosis) and hypotension. Bacteremia with meningitis: sudden onset of fever, nausea, vomiting, headache, decreased ability to concentrate, and myalgias
• Disease progresses rapidly (within hours).
• Skin findings and hypotension may be present.
  • A petechial rash appears as discrete lesions 1 to 2 mm in diameter; most frequently on the trunk and lower portions of the body; seen in >50% of patients on presentation
  • Purpura fulminans is a severe complication of meningococcal disease and occurs in up to 25% of cases. It is characterized by acute onset of cutaneous hemorrhage and necrosis due to vascular thrombosis and disseminated intravascular coagulopathy (DIC).

Epidemiology

Incidence

• The mortality rate is ~13%.
  • 11–19% of survivors suffer serious sequelae, including deafness, neurologic deficits, or limb loss.
• Disease is seasonal, peaks in December/January.
• Atypical clinical presentations include abdominal symptoms, septic arthritis, and bacteremic pneumonia.
• Peak incidence occurs in the first year of life; 35–40% of cases occur in children aged <5 years. A second peak occurs in adolescence.
• In 2021 (most recent CDC data), there were 210 cases of reported meningococcal disease (incidence rate of ~0.2 cases per 100,000 persons) (1); most common in adolescents and young adults, followed by infants <1 year

Etiology and Pathophysiology

• N. meningitidis is a fastidious, aerobic, gram-negative diplococcus with at least 13 serotypes.
• N. meningitidis has an outer coat that produces disease-causing endotoxin. Virulence factors promote invasive disease.
• Humans are the only known reservoir for N. meningitidis.
• Major serogroups in the United States are B, C, Y, and W-135.
  • Serogroup B is the predominant cause of meningococcemia in children aged <1 year.
  • Serogroup C is the most common cause of meningococcal disease in the United States.
  • Serogroup Y is the predominant cause of meningococcemia in the elderly (2).
• Major serogroups worldwide are A, B, C, Y, and W-135.
  • W-135 is the major cause of disease in the “meningitis belt” of sub-Saharan Africa.

Genetics
Late complement component deficiency has an autosomal recessive inheritance.

Risk Factors

• Age: 3 months to 1 year
• Late complement component deficiency (C5, C6, C7, C8, or C9)
• Asplenia (1)
• Living in close quarters (e.g., household contacts, nursery/daycare, dormitories, military barracks)
• Exposure to active (and/or) passive tobacco smoke (1)

General Prevention

• Meningococcal ACWY Vaccines (MenACWY):
  • Infants and children: routine vaccination for high-risk children aged 2 months and older
  • Adolescents: first dose typically at age 11 or 12 years, with a booster at age 16 years. Teens and young adults (16 through 23 years old) may also receive a serogroup B meningococcal vaccine.
  • At-Risk adults: Adults with certain risk factors or who are in an area with an outbreak should also be vaccinated.
• Meningococcal B vaccines (MenB):
  • Infants and children: not routinely recommended for all children but may be given to those at increased risk
  • Adolescents and young adults: may be administered to individuals aged 16 to 23 years (preferred age is 16 to 18 years) who are not at increased risk, based on shared clinical decision-making
  • At-risk individuals: recommended for individuals 10 years and older who are at increased risk
  • Special populations: Individuals with certain medical conditions, laboratory workers, or travelers to areas where meningococcal disease is common might also need vaccination.
  • Protective levels of antibody are achieved ~7 to 10 days after primary immunization (2).
  • CDC international travel advisory: vaccine required for Hajji pilgrims >2 years of age; given to travelers to sub-Saharan Africa (“meningitis belt”)