- Gram (-), kidney or coffee-bean shaped intracellular diplococci
- Ferments glucose and maltose with acid production but not sucrose or lactose
- Inhabits the nasopharynx of sick persons and carriers
- Portal of entry: nasopharynx; invades bloodstream and enters the meninges of the brain
- Mode of transmission: direct personal contact through droplet infection from a sick person or carrier
- Causes meningococci meningitis or spotted fever
- P substance – a protein substance common to all types of meningococci; highly toxic to rabbits
- C substance – a polysaccharide found in all types of meningococci
- Type-specific antigen – a polysaccharide polypeptide complex found in types 1 and 3
Meningococci Meningitis or Spotted Fever
- It is an acute, communicable bacterial disease affecting the meninges.
- It is always serious.
Signs and Symptoms
From the bloodstream, the infecting organisms may cross the blood-brain barrier and infect the meninges, causeing the major symptoms of:
- Severe headache
- Chills with high grade fever
- Rapid pulse
- Convulsions (especially in infants)
- Rigidity of the muscles especially those of the neck and back
- Orthotonus (head becomes fixed, body and limb in rigid straight line)
- Pain on flexing the neck
- Kernig’s sign (knees become fixed and cannot be extended)
- Brudzinski’s sign (elevation of the head, thorax and legs)
- Delirium progressing to stupor (unconscious stage)
- Penicillin G as the drug of choice. It inhibits cell wall synthesis.
- Sulfonamides especially sulfadiazine and sulfamerazine are alternative drugs of choice since they can readily cross the blood-brain barrier. Acts as bacteriostatic and atntimetabolites of PABA (para-amino-benzoic acid).
- Cephalosporin like cefotaxime, chloramphenicol or chloromycetin and erythromycin are third generation drugs effective in persons allergic to penicillin. They inhibit also cell wall synthesis.
- Rifampicin 600 mg can eradicate the carrier state and can be used for chmoprophylaxis for household and other close contact.
Prevention and Control
- Isolation of sick persons
- Treatment of carriers
- Awareness against sneezing of infected individuals
- Skin care
- Oral and nasal hygiene
- Maintenance of clean surrounding
- Reduction of personal contacts in a population with a high carrier rate. This can be done by avoidance of crowding.
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