meningitis

Question 1

what is meningitis

Answer 1

disease caused by inflammation of the meninges

Question 2

what is meningism

Answer 2

clinical signs and symptoms suggestive of meningeal irritation

Question 3

Answer 3

Question 4

signs and symptoms of meningitis in older children

Answer 4

• fever
• headache
• photophobia
• neck stiffness - nuchal rigidity

raised ICP:

• N+V
• reduced GCS
• seizures
• focal neurological deficits

Question 5

signs and symptoms of meningitis in young infants

Answer 5

• fever/hypothermia
• poor feeding
• vomiting
• lethargy
• irritability
• resp distress
• apnoea - pause in breathing for at least 20s, signs of significant resp distress and reduced resp drive
• bulging fontanelle - raised ICP

Question 5

signs and symptoms of meningitis in young infants

Answer 5

• fever/hypothermia
• poor feeding
• vomiting
• lethargy
• irritability
• resp distress
• apnoea - pause in breathing for at least 20s, signs of significant resp distress and reduced resp drive
• bulging fontanelle - raised ICP

Question 6

clinical signs of meningitis

Answer 6

• nuchal rigidity - palpable resistance to neck flexion
• Brudzinski’s sign - hips and knees flex on passive flexion of the neck
• Kernig’s signs - flex hip and knee to 90 degrees, pain of passive extension of the knee

Question 7

causes of child meningitis

Answer 7

• bacterial - 4-18%
• viral - mainly enterovirus, 54-88%
• fungal - neonates, immunocompromised
• unknown/aseptic - 40-76%

Question 8

bacterial meningitis - causative organisms in neonates (<1m)

Answer 8

group B streptococcus

Escherichia coli

Listeria monocytogenes

Question 9

bacterial meningitis - causative organisms in older infants and children

Answer 9

Streptococcus pneumoniae

Neisseria meningitidis

Haemophilus influenzae type B- uncommon now following vaccination

Question 10

what type of bacterial is Haemophilus influenzae

Answer 10

small

non-motile

gram -ve

coccobacillus

Question 11

where is H influenzae carried

Answer 11

nasopharyngeal carriage

Question 12

what is encapsulated H. influenzae and why is it important

Answer 12

• resist phagocytosis and complement mediated lysis
• 6 serotypes (a-f)
  
  • Hib - main cause of invasive H. influenzae infection
• bacteraemia, meningitis, epiglottitis, pneumonia
• RF - asplenia, sickle cell disease, antibody deficiency

Question 13

non-encapsulated H. influenzae

• what does it lead to

Answer 13

aka non typeable H. influenzae (NTHI)

• otitis media and sinusitis
• invasive infection is rare

Question 14

what meningococcal serotype causes the majority of invasive meningococcal disease

Answer 14

B

Question 15

what type of bacteria is Neisseria meningitidis

Answer 15

gram -ve diplococcus

Question 16

carriage and transmission of Neisseria meningitidis

Answer 16

humans are the only natural host

nasopharyngeal carriage

transmission via resp secretions

infection often follows URTI

Question 17

structure of Neisseria meningitidis

Answer 17

polysaccharide capsules

• capsule composition determines serogroup e.g. A, B, C, W, Y

endotoxin production (LPS) - this is why it can leading to overwhelming sepsis

Question 18

risk factors for invasive meningococcal disease

Answer 18

• <1y, 15-24y/o
• unimmunised
• crowded living conditions
• household or kissing contact
• cigarette smoking (active or passive)
• recent viral/mycoplasma infection
• complement deficiency

Question 19

features of invasive meningococcal disease

• meningitis
• sepsis

Answer 19

• 15% have isolated featrues of meningitis
• 25% isolated sepsis
• 60% have features of both

Question 20

rash in invasive meningococal infection

Answer 20

starts off as a blanching maculopapular rash

progresses to petichiae or purpura

purpura fulminans - purpura coaslesce together to form bruise like lesions (poor tissues perfusion and can lead to necrosis)

Question 21

prognosis of meningococal disease - mortality and significant long term sequelae

Answer 21

rapidly progressive

case fatality 5-15%

• 50% of deaths in 1st 12h
• 80% of deaths in 1st 48h

significant long term sequelae

• amputation 14%
• scarring 48%
• hearing loss
• cognitive impairment/epilepsy

Question 22

what type of bacteria is streptococcus pneumoniae (pneumococcus)

Answer 22

gram +ve

lancet shaped

diplococcus

facultative anaerobe

Question 23

capsule in streptococcus pnuemoniae

Answer 23

polysaccharide capsule

• inhibits neutrophil phagocytosis
• inhibits complement mediated cell lysis

Question 24

serotypes of streptococcus pnuemoniae

Answer 24

\>90 known serotypes all serotypes can cause invasive disease

Question 25

where does streptococcus pnuemoniae colonise

Answer 25

colonises nasopharynx (11-93%) carriage is higher in nursery aged children and in adolescence

Question 26

what often precedes streptococcus pnuemoniae invasive infection

Answer 26

preceeding viral URTI

Question 27

transmission of streptococcus pnuemoniae

Answer 27

respiratory droplet

Question 28

pneumococcal infection - colonisation vs invasive infection

Answer 28

* otitis media, sinusitis * meningitis * septicaemia * pneumonia, empyaema * peritonitis * arthritis, osteomyelitis

Question 29

risk factors for invasive pneumococcal disease

Answer 29

* age \<2 * cigarette smoking (active/passive) * recent viral URTI * attendance at childcare * cochlear implant * sickle cell disease * asplenia * HIV infection * nephrotic syndrome * immunodeficiency/immunosuppression

Question 30

prognosis of pneumococcal meningitis

Answer 30

case fatality in children 8% neurological sequelae common: * hydrocephalus * neurodisabilty * seizures * hearing loss * blindness

Question 31

management of meningitis

Answer 31

Airway Breathing Circulation - 20ml/kg fluid bolus, inotropes DEFG - 2ml/kg 10% dextrose abx - 3rd gen cephalosporin (e.g. cefotaxime, ceftriaxone), add amoxicillin if \<1mth to cover for listeria

Question 32

investigations for meningitis

Answer 32

BLOODS: * FBC - leukocytosis, thrombocytopaenia * U+Es, LFTs * CRP * coagulation screen - DIC * blood gas - metabolic acidosis, raised lactate * glucose * **BLOOD CULTURE** * meningococcal/pneumococcal PCR LUMBAR PUNCTURE: * **essential** * ideally prior to abx but **don't delay abx if LP cannot be performed**

Question 33

CI to LP

Answer 33

* signs of raised ICP: GCS \<9, abnormal tone/posture, HT and bradycardia, pupillary defects, papilloedema * focal neurological signs * recent seizure (within 30 mins), if recent long seizure avoid LP for longer * CV instability * coagulopathy * thrombocytopenia * extensive/extending purpura

Question 34

what to request on LP

Answer 34

microscopy gram stain culture protein glucose viral PCR

Question 35

findings on LP from bacterial meningitis

Answer 35

* turbid or purulent * high opening pressure * +++ WCC (polymorphs) * +++ protein * --glucose (\<50% serum)

Question 36

treatment durations for bacterial meningitis

Answer 36

N meningitidis - 7 days H influenzae - 10 days strep pneumoniae - 14 days group B strep - ≥14 days Listeria monocytogenes - 21 days