Neisseria meningitides

Neisseria meningitides is a diplococci (gram-negative) which is responsible for meningitis and septicaemia. It is part of the normal flora in 30% of the population, but it is not known how the bacterium is transformed to become pathogenic. This bacteria is picked up by passing droplets between humans.

The bacteria attach to the cells of the nasopharynx (upper part of the pharynx), where they gain access to the bloodstream.

Once in the bloodstream the bacterium replicates and causes swelling of the lining around the brain and spinal cord. The symptoms of meningitis include:
• Severe headache
• Stiff neck
• Dislike of bright lights
• Fever/vomiting
• Drowsy and less responsive
• Rash (which does not disappear when a glass is rolled over it)

Septicaemia is a form of blood poisoning, the symptoms include:
• Rash (which does not fade when a glass is pressed over it)
• Fever and vomiting
• Cold hands and feet
• Shivering
• Rapid or unusual breathing
• Stomach/joint/muscle pain
• Drowsy and less respondent

Penicillin is the drug which usually treats this infection; however, some resistance has arisen. Chloramphenicol can also be used to treat this bacterium. A vaccine is also available.