Meningococci are a major cause of bacterial meningitis and septicemia. There are several meningococcal serogroups, but serogroups A, B, C, Y, and W135 account for 99% of cases of invasive infection.
Symptoms of meningococcal infections
Meningococcal meningitis usually occurs during infancy, adolescence and young adulthood and is characterized by an infectious syndrome (fever, severe headaches, vomiting) with meningismus (stiffness of the neck, lethargy, consciousness disorder, and even coma).
Purpura fulminans (or fulminant meningococcal septicemia) is seen in 10 to 20% of patients (15). It is characterized by infectious shock and extensive, often ecchymotic, purpura. The mortality rate is high and the sequelae drastic.
Epidemiology and vaccination against meningococcal infections
Although invasive meningococcal infections mostly appear in the form of sporadic cases or minor epidemics, unpredictable and devastating epidemics do occur in certain geographical areas, such as the “African meningitis belt.” (16)
Transmission of meningococci occurs via airborne respiratory droplets expelled by infected patients or healthy carriers.
Several types of meningococcal vaccines are available.
15 - Granoff DM. Meningococcal vaccines. In: "Vaccines" Plotkin A., Orenstein W. Fourth edition 2004. Saunders Editor p 959-987
16 - Meningococcal vaccines. WHO position paper. WER 2002, 77, 329-340: