Invasive Meningococcal Disease (IMD)
- 12 groups of N. meningitidis bacteria, called serogroups, have been identified based on variations in the biochemical composition of their polysaccharide capsules.
- The polysaccharide capsule is key in determining virulence. 2
- 5 of these serogroups—A, B, C, W and Y—are responsible for most cases of IMD.
Clinical forms of IMD1:
The 3 main clinical forms are:
- Meningitis ( an acute inflammation of the membranes that surrounds the brain and spinal cord),
- Meningococcal sepsis (infection of the bloodstream, also known as meningococcemia) and
Complications of IMD:
- Mortality rate:
Between 5 to 10% of patients die, even with appropriate antibiotic therapy. 7
It reaches up to 40% with meningococcemia. 1
- Surviving IMD - Physical, cognitive and psychological sequelae: 16
As many as 20% of survivors have permanent sequelae, such as, but not limited to brain damage, hearing loss, loss of a limb and learning difficulties.
Parents of children with severe episodes of IMD have reported experiencing psychological distress for months and even years afterwards.
- Centers for Disease Control and Prevention. Epidemiology and Prevention of Vaccine-Preventable Diseases. Chapter 14: Meningococcal Disease. Hamborsky J, Kroger A, Wolfe S, eds. 13th ed. Washington D.C. Public Health Foundation, 2015
- Harrison LH, Trotter CL, Ramsay ME, Global epidemiology of meningococcal disease, Vaccine, 2009;27(Suppl2):B51-B63
- Rosenstein NE, Perkins BA, Stephens DS et al, Meningococcal Disease, N Engl J Med, 2001;344:1378-1388
- Caugant DA, Maiden MC, Meningococcal carriage and disease—Population biology and evolution, Vaccine, 2009;27(Suppl2):B64-B70
- Watson P, Turner D., Clinical experience with the meningococcal B vaccine, Bexsero®, Vaccine, 2016;34(7):875-880
- Ehrlich TR et al., Long-term psychological distress in parents of child survivors of severe meningococcal disease, Pediatr Rehabil., 2005;8(3):220-224
- World Health Organization (WHO). Meningococcal meningitis fact sheet No. 141, 2015. Available at: http://www.who.int/mediacentre/factsheets/fs141/en. Last accessed December 2016