Pathophysiology of Meningitis
What is meningitis
- acute inflammation of the meninges
- which covers the brain and spinal cord
Which bacteria causes bacteremia
N. Meningitidis and S. Pneumoniae
What are the 2 types of hypersensitive reactions to antibiotics
- immediate
- delayed
Which types of meningitis strands can cause an epidemic
A,B,C,W,X,Y
Symptoms of meningitis
- fever
- headache
- neck stiffness
- confusion
- inability to tolerate light
- vomiting
- rash
Name 3 viral causes of meningitis
- enterovirus
- herpes simplex virus
- varicella zoster virus
- mumps
- HIV
- LCMV - lymphocytic choriomeningitis virus (rodent borne)
What type of immune cells are recruited in a type 4 hypersensitivity reaction
T cells
Outline 3 ways to prevent meningitis transmission via surveillance
- behavioural
- vaccination
- education
- screening
- passive
- active
- sentinel
- enhanced
- syndromic (GP)
Once the bacteria has entered the bloodstream, which part of the meninges does it travel to
subarachnoid space, in places where the blood-brain barrier is vulnerable (choroid plexus)
Causes of nosocomial meningitis infections
- S. pneumonia
- Staphylococcus aureus
- Staphylococcus albus
- gram-negative bacilli
Which antibodies are involved in a type 2 hypersensitivity reaction
- IgG or IgM
- and complement
- cytotoxic
Which strand is most common between the ages 11-17
neisseria meningitis
Which immune cells in the brain detect components of the bacterial cell membranes
- astrocytes
- microglia
How is the CSF in bacterial meningitis characterised
strongly elevated white blood cell count (<500 cells/μl) with predominant neutrophils and a highly elevated protein (< 1 g/l), indicating severe blood—CSF barrier disruption
Explain a type 3 hypersensitivity reaction
- drug immune complex reactions
- they bind to endothelial cells
- complement activation in small blood vessels
Explain the concept of the R number and estimate the value for meningitis
- the R number is the average number of new individualswho will contract an infectious disease from a singleinfected person
- 1.31 (2016)
Which pathological changes predominantly cause headaches and fever
lipopolysaccharides in the gram negative and techoic acid in the walls of gram positive activate the brain microglia. This leads to inflammatory cascade, changing the permeability of cortical microvascular structures increasing intracranial pressure
Which bacteria cause meningitis in adults specifically
- neisseria meningitides
- streptococcus pneumoniae
- listeria monocytogenes
Explain a type 1 hypersensitivity reaction to an antibiotic
drug allergens bind to IgE antibodies attached to mast cells and basophils
results in IgE cross linking
releasing mediators
Which vaccinations can help prevent against meningitis
- Men B
- Men C / HIB
- 6-1 vaccine. (diphtheria, tetanus, whooping cough, hep B, polio, haemophilus influenza type B)
- Pneumococcal
- MMR
- MenACWY