Meningococcal disease is a rare, but potentially devastating infection. It is caused by the bacteria Neisseria meningitidis of which there are 6 disease-causing strains called serogroups (A, B, C, W, Y and X). Approximately 10 percent of the general population of the UK are thought to carry N. meningitidis in the lining of the nose and throat. Spread between individuals occurs through coughing, sneezing, kissing or during close contact with a carrier. Carriers do not have symptoms, but can develop disease when bacteria invade the bloodstream from the nasopharynx (area at the back of the nose and throat). Invasive disease is a rare but serious outcome usually presenting as septicaemia (blood poisoning) or meningitis (infection of the lining of the brain).
In most parts of the world meningococcal disease occurs as occasional cases in individuals or in small clusters. The disease is most common in the ‘meningitis belt’ of sub-Saharan Africa, which extends across the dry savannah regions from Senegal in the west, to Ethiopia in the east. These outbreaks occur particularly during the dry season and are most commonly caused by serogroup A. Following several large outbreaks associated with pilgrimage to the Kingdom of Saudi Arabia all those travelling for the Hajj or Umrah are currently required to show proof of vaccination with quadrivalent vaccine (protecting against the A,C,W and Y serogroups) in order to obtain a visa.
Invasive meningococcal disease usually presents as meningitis or septicaemia. Symptoms of meningitis include: sudden onset of fever, intense headache, neck stiffness, nausea and vomiting. Symptoms of septicaemia include: fever, chills, confusion and a rash. Both conditions may progress rapidly and are serious diseases with high risk of complications.