20-21 Infection Flashcards
What is Waterhouse-Friderichsen syndrome?
Complication of meningococcal infection, occurs in 10-20% of children with acute meningitis. Petechial haemorrhages and haemorrhage into adrenals and DIC.
Increased ICP may occur
What are the commonest pathogens causing meningitis in immunocompetent patients?
Neisseria Meningitidis
Strep Pneumoniae
H. Influenza Type B
Which form of meningitis is likely to present with hydrocephalus?
Cryptococcal meningitis
Usual organisms in post-neurosurgical procedure meningitis?
coag -ve staph
staph aureus
enterobacter
pseudomonas
What pathogens to consider in immunocompromised with infection?
Cryptococcus
TB
Listeria Monocytogenes
HIV aseptic meningitis
How do you treat a post traumatic meningitis?
broad spectrum ABx with good CNS penetration e.g. Vanc and Mero.
Pneumococcal vaccine as most commonly associated with a CSF leak.
Consider exploration or insertion with lumbar drain. May stop spontaneously but this may be due to obscuration by encarcerated brain and high potential for CSF leak later.
Causes of recurrent meningitis?
dermal sinus,
CSF fistula,
neurenteric cyst
Causes of chronic meningitis?
TB
fungal infections
neurocystericosis
Borrelia burgdorferi causes what neurological deficit?
BB -> Lyme disease. Can cause facial nerve weakness. May appear weeks after the initial rash
WHat is the treatment for Listeria monocytogenes?
Ampicillin and gentamicin. (Cephalosporins are inactive against listeria) treat for 21 days
Commonest pathogen causing cerebral abscesses?
streptococcus
What stage does necrosis begin in abscess formation?
Stage 2 - late cerebritis (day 4-9)
What are the stages of abscess formation?
Stage 1 - early cerebritis Day 1-3
Stage 2 - late cerebritis Day 4-9
Stage 3 - early capsule Day 10-14
Stage 4 - late capsule >14days
What stage of abscess formation do you get neovascularisation?
Stage 3 - early capsule - Day 10-14
What is different about the scarring left by an abscess?
Collagen scar as opposed to glial scar
Commonest cause of fungal abscesses?
Aspergillus - although uncommon to cause meningitis or meningoencephalitis
What organism causes neurocytercosis?
Taenia solium
child with polycystic lesion (and ?fever)
Echinococcus
What percentage of subdural empyemas occur in the spine?
5%
what is the likely pathogen in a brain abscess secondary to otitis externa?
Pseudomonas
In what condition might you see oculomasticatory myorhythmia?
Whipples disease
What is the commonest neurological involvement in HIV/AIDS
AIDS encephalopathy
Commonest part of the spine to get epidural abscesses?
Thoracic (50%) then lumbar (35%) then cervical (15%)
Most are posterior (82%)
Commonest source of infection in spinal epidural abscess?
Haematogenous spread from skin infections.
Furuncle may be found in 15% of cases.
What is the risk of treating spinal epidual abscess with antibiotics alone?
Can develop rapid neurological deterioration (mechanism may be compression, venous infarcts or direct infiltration of infection into spinal cord)
Which patients should have abx treatment only with spinal epidural abscess?
Antibiotic treatment should be reserved for
- patients unfit for GA
- Involvement of extensive length of spinal canal
- Complete paralysis >3days
Commonest pathogen to cause vertebral osteomyelitis and spinal epidural abscess?
Staph Aureus
In VB osteomyelitis what is the yield from blood cultures versus needle biopsy?
50% for blood cultures
60-90% for needle biopsy
15% get different organisms from BC vs needle Bx!
Pathogen that is most likely to cause discitis in IVDU?
Pseudomonas
What are the risk factors for shunt infection in myelomeningocoele patients?
Age - evidence that waiting until child is 2 weeks old reduces risk of infection
longer procedure - shunting at same time as repair associated with higher risk of infection
open defect more likely to get infected.
Which pathogens most likely to cause infections in neonates?
E Coli
Strep haemolyticus
What is an additional complication of a ventriculovascular shunt?
shunt nephritis - immune complex deposition in renal glomeruli
How does gram -ve bacillus infection differ from staph CSF infection
More severe clinical course
higher protein and lower glucose with more neutrophils on CSF analysis
What antibiotics would you start a patient with shunt infection on?
IV Vancomycin and Meropenem
Organism associated with haemolytic uraemic syndrome?
E.Coli
