Neisseria Meningitidis Flashcards
Where is neisseria meningitidis found in the normal flora?
Nasopharynx.
What is the structure of NM?
Gram-negative diplococci - has a polysaccharide capsule and are arranged in pairs.
How does transmission of NM occur, and what are the risk factors?
Inhalation of respiratory droplets.
Risk factors:
- recent upper respiratory tract infection.
- smoking.
- co-morbidities.
What part of NM is the toxic part?
The lipopolysaccharide endotoxin.
How does NM become dangerous if it normally colonises in the body?
When it invades beyond the nasopharynx, and enters the blood, it leads to meningitis.
What are the symptoms of NM?
Can sometimes be non-specific and feverish in less serious cases.
It can cross the BBB, infecting the meninges. In these more serious cases, it can cause:
- Non-blanching rash.
- Fever.
- Malaise and headache.
- Photophobia.
- Rigid neck.
- Nausea and vomiting.
How do you test for NM?
Lumbar puncture to test CSF.
Gram stain it.
Throat swab to see if it is in the normal flora - usually a test for carriers.
How is NM cultured?
Chocolate agar with increased CO2.
Outline the treatment of NM.
IV ceftriaxone.
What do the NM vaccines use?
Sections of the polysaccharide capsule.
Other than meningitis, what can NM cause?
Septicaemia.
They can occur together or separately.
Pneumonia.
What will septicaemia cause?
Fever, sepsis, DIC, and rash.
Outline the 3 forms of non-blanching rash.
Petechiae - small red spots 1-2mm in diameter.
Ecchymoses - larger lesions, greater than 10mm.
Necrosis - combination of vascular damage, lack of blood to the skin and periphery, and small clots and haemorrhage.
Outline some bacterial, viral and fungal causes of meningitis.
Outline the CSF results from bacterial, TB, viral and fungal meningitis.
