Infection & Immunity - Meningococcaemia & Sepsis

Question 1

Incidence of meningococcemia?

Answer 1

> 80% patients with bacterial meningitis younger than 16, 5-10% mortality
10% survivors left with long-term neurological impairment

Question 2

Describe the pathphysiology of Neisseria meningitides

Answer 2

• Meningitis after bacteraemia
• Damage caused by host response to infection + not from organism itself
• Release of inflammatory mediators + activated leucocytes
• Endothelial damage
• Result in raised ICP + decreased cerebral blood flow
• If inflammatory response below meninges causing vasculopathy resulting in cerebral cortical infarction
• Fibrin deposits may block resorption of CSF by arachnoid villi, resulting in hydrocephalus

Question 3

How does meningococcaemia present?

Answer 3

fever
headache 
photophobia 
lethargy 
poor feeding/vomiting 
irritability 
hypotonia
drowsiness
loss of consciousness 
seizures 
purpuric rash 
neck stiffness 
bulging fontanelle 
opisthotonus 
signs of shock - tachycardia, tachypnoea, prolonged cap refill, hypotension

Question 4

What is the Brudzinski sign?

Answer 4

flexion of neck with child supine, causing flexion of knees and hips

Question 5

What is the Kernig sign?

Answer 5

child lying supine and with hips and knees flexed

back pain on knee extension

Question 6

What is the NICE guidelines on febrile children with purpura?

Answer 6

Purpura in a febrile child pf any age should be assumed to be meningococcal sepsis

Give IM benzylpenicilllin immediately and transfer to hospital

Question 7

What is purpura?

Answer 7

characteristic non blanching purpuric skin lesions, irregular in size and outline with a necrotic centre
fulminant - extensive lesions

Question 8

What is the acute management of fulminant meningococcal sepsis and meningitis?

Answer 8

antibiotics and supportive therapy
cefotaxime or ceftriaxone preferred
length of course depends on causative organism and clinical response
dexamethasone reduces deafness

Question 9

What is important to remember about meningococcal sepsis and meningitis?

Answer 9

Notifiable disease

Prophylactic treatment to all household contacts

Question 10

What are the potential complications of meningitis?

Answer 10

hearing loss
local vasculitis - may lead to cranial nerve palsies
local cerebral infarction - focal or multifocal seizures
subdural effusion
hydrocephalus
cerebral abscess

Question 11

What rare underlying immunological deficits may lead to recurrent meningococcaemia?

Answer 11

lack of proteins that are responsible for bactericidal killing of N.meningitidis

Question 12

What is sepsis?

Answer 12

presence of infection in conjunction with the systemic inflammatory response syndrome

Question 13

What are the causative organisms for early neonatal sepsis?

ascending infection from birth canal

Answer 13

GBS
E.coli
H.Influenza
Listeria

Question 14

What are the causative organisms for late neonatal sepsis?

Answer 14

Staph. Epidermidis
Staph. Aureus
E. Coli
Klebsiella
Pseudomonas
Enterobacter
Serratia
Candida

Question 15

What are the causative organisms for sepsis in infants and childhood?

Answer 15

Hib
Strep pneumonia
N. meningitides
Salmonella

Question 16

What is the main causative organism in immunodeficient patients and those with chronic respiratory illness?

Answer 16

pseudomonas

Question 17

How does sepsis present clinically?

Answer 17

fever 
poor feeding 
miserable, irritable, lethargy 
Hx of focal infection
Predisposing conditions
Tachycardia, tacypnoea, low BP 
Purpuric rash in meningococcal sepsis 
Shock 
Muli-organ failure

Question 18

What are the red flags in children with sepsis?

Answer 18

Fever >38 if <3 months or >39 if 3-6 months
Colour – pale, mottled, blue
Level of consciousness reduced, neck stiffness, bulging fontanelle, status epilepticus, focal neurological signs or seizures
Significant respiratory distress
Bile-stained vomiting
Severe dehydration or shock

Question 19

What is included in a septic screen?

Answer 19

Blood cultures
FBC inc WCC
CRP
Urine sample
Consider: CXR, LP, rapid antigen screen, meningococcal/pneumococcal PCR, PCR for viruses in CSF

Question 20

When is the threshold low for performing a septic screen?

Answer 20

younger the child the lower the threshold

Question 21

Define shock

Answer 21

circulation is inadequate to meet demands of tissues

Question 22

What are the early clinical signs of shock?

compensated

Answer 22

tachypnoea 
tachycardia 
decreased skin turgour 
sunken eyes and fontanelle 
delayed cap refill (>2secs) 
mottled, pale, cold skin 
core-peripheral temp gap
decreases urinary output

Question 23

What are the late clinical signs of shock?

uncompensated

Answer 23

acidotic breathing
bradycardia 
confusion/depressed cerebral state 
blue peripheries 
absent urine output 
hypotension

Question 24

Which abx are given in the first 6-8 weeks of life for sepsis?

Answer 24

ampicillin + one of the following: gentamycin, cefotaxime, ceftriaxone

Question 25

What abx are given to older infants and children?

Answer 25

3rd gen cephalosporin

Question 26

How is sepsis treatment escalated?

Answer 26

• provide abx cover
• fluid resuscitation
• if no improvement or - progression of shock
• paediatric ICU
• poss tracheal intubation and mechanical ventilation
• invasive monitoring of BP
• inotrophic support
• correct haematological, biochemical and metabolic derangements
• support for renal or liver failure