Meningitis and Neisseria meningitidis

Question 1

Describe the anatomy of the CSF

What is its function

Answer 1

Flows within the sub-arachnoid space of the meninges, and fills Ventricles (open spaces) of the brain

Maintains constant intercranial pressure

Question 2

Where and how is CSF produced

Answer 2

Choroid plexus in the lining of ventricles, by filtration of plasma by epithelial cells.

Glucose, some protein, and few/ none cells (Lymphocytes)

Question 3

Which 3 organisms cause meningitis

Answer 3

Bacteria:
Neisseria meningitidis
S. pneumoniae
H. influenzae

Viruses:
Herpes viruses (Simplex virus 1 and 2)
Enteroviruses (Echoviruses, poliovirus, coxsackie A and B)

Fungi:
Cryptococcus neoformans

Question 4

Which meningitis-causing organism group is;

1. Most severe
2. Most common and often recover without treatment
3. Rare and most at risk to immunocompromised people

Answer 4

1. Bacteria
2. Viruses
3. Fungi

Question 5

For Normal, Bacterial and Viral infected CSF, describe the;

1. Appearance
2. WBC count
3. Usual cel type
4. Protein (g/L)
5. Glucose (mmol/L)

Answer 5

Normal:

1. Clear
2. <5
3. -
4. <0.4
5. 2.6-4.6 (a third of serum concentration)

Bacterial:

1. Cloudy
2. > 100
3. Neutrophils
4. Increased
5. Low

Viral;

1. Clear
2. 5-1000
3. Lymphocytes
4. Moderate increase
5. Normal OR slightly decreased

Question 6

Describe 6 clinical signs of meningitis

Answer 6

1. Photophobia
2. Headache
3. Neck stiffness
4. Vomiting
5. Irritable (Progresses to reduced consciousness)
6. General features of infection (Fever, tachycardia)

Question 7

What are 6 features of Neisseria meningitidis

Answer 7

• Gram negative
• Diplococcus
• May be found within neutrophils
• Polysaccharide capsule
• Multiple serogroups
• Pilia

Question 8

What 3 groups of people are most likely to get Meningococcal disease

What 2 diseases can be caused by Neisseria meningitidis? How?

How is meningitis spread

Answer 8

Young children/ adolescents/ adults

Meningitis: Bacteria in CSF attach to meningeal lining-> inflammation

Septicaemia: If bacteria gets into blood->Fever and/or sepsis

Via Aerososols + Nasopharyngeal secretions

Question 9

List 4 clinical features of Neisseria meningitidis

Answer 9

1. Can cause Meningitis/ Septicaemia
2. Disseminated Intravascular Coagulation
3. Rash (Petechiae/ ecchymoses) may present
4. Necrosis

Question 10

What is DIC (Disseminated Intravascular Coagulation)

What are its 2 main mechanisms

Answer 10

Widespread Intravascular activation of coagulation

• Activation of inflammatory cytokines
• Insufficient control of anti-coagulation pathways

Question 11

Outline how DIC leads to formation of 2 types of rash

These are non-blanching rashes, which test is used to determine this

Answer 11

1. Platelets used up in clotting
2. Small bleeds into skin occur-> PETECHIAE
3. Petechiae coalesce-> larger ECCHYMOSES

Tumbler test

Question 12

What are the most infectious serous groups of N. mengitidis

Which serous groups cause 90% of meningitis cases

Answer 12

Most infectious: A,C,W,Y

90% of cases: A,B,C

Question 13

What are 5 steps in management of Meningococcal septicaemia

Answer 13

1. Early detection
2. Early administration of antibiotics
3. Urgent investigation
4. Supportive care (Often in ICU)
5. Notify public health England

Question 14

What antibiotic is given in case of suspected meningitis and how?

Answer 14

IV Ceftriaxone

Question 15

List the 6 vaccines given to protect against N. meningitidis

Answer 15

1. MenB
2. 6-in-1 vaccine
3. Pneumococcal
4. MenC/ HiB
5. MMR
6. MenACWY

Question 16

What diseases are protected against in the 6-in-1 vaccine

Answer 16

Diphtheria 
Tetanus
Whooping cough
HiB (Can cause meningitis)
Polio
HepB