An early rash A more advanced stage. Meningococci are quite common. They live in the back of the nose and throat. Such people are called healthy carriers of meningococci. Once a person becomes a carrier, the infection may last for up to 4-6 months.
Meningococcal bacteria cause disease only in susceptible persons.
Although many people are carriers of meningococci, only 1-2 out of every 100,000 people get a serious illness such as meningococcal meningitis or meningococcal septicemia every year. A person is susceptible to meningococcal disease if he or she has no immunity against the strain infecting the back of the nose and throat. In particular, the persons lacks antibodies in the blood, special proteins produced by the immune system which kill the meningococci before they can cause any damage. In a susceptible person, the bacteria are able to move across the lining of the nose and throat and into the blood. Once in the blood, they multiply and produce toxins or poisons.