infections Flashcards
commonest cause of meningitis in neonates
Group B Streptococcus
(then E.coli, listeria moncytogenes)
commonest cause of meningitis in kids and adults
neisseria meningitidis
strep pneumoniae
commonest cause of meningitis in immunosuppressed
listeria monocytogenes
meningococcal septicaemia
= when meningococcus is in bloodstream
o cause of non-blanching rash -> indicates disseminated intravascular coagulopathy (DIC) + subcutaneous haemorrhages
presentation of bacterial meningitis
headache, fever
photophobia, neck stiffness
drowsiness
non-blanching rash (meningococcal septicaemia)
Neonates + babies -> Non-specific
Hypotonia
Poor feeding
Lethargy
Hypothermia
Bulging fontanelle
which test are used in suspected meningitis
Kernig’s test
o Lying on back, flexing one hip + knee to 90 then slowly straightening knee whilst keeping hip flexed at 90
Creates stretch in meninges -> will produce pain or resistance to this movement
Brudzinski’s test
o Lying on back lift their head + neck off bed + flex chin to chest
Positive – involuntary flex of hips + knees
meningitis investigations
lumbar puncture
CT
MRI
when to delay lumbar puncture
raised ICP
continous or uncontrolled seizure
GCS <=12
appearance of bacterial CSF
cloudy
high protein
low glucose
high WCC (neutrophils)
appearance of viral CSF
clear
protein normal/mildy raised
normal glucose
high WCC - lymphocytes
management of kids in community with suspected meningitis AND non-blanching rash
IM benzylpenicillin
<1yr - 300mg
1-9yr - 600mg
>10yrs - 1200mg
then immediate transfer to hospital (watch for pen allergy)
Management of meningitis
IV antibiotics
- <3months = amoxicillin + ceftriaxone
- 3month-50yrs = ceftriaxone
- >60yrs = ceftriaxone + amoxicillin
IV dexamethosome
- esp if strep pneumoniae
- start before or with 1st dose of Abx - no later than 12hrs after
- NOT in shock, septicaemia, *following surgery
prophylaxis for meningitis contacts
ciprofloxacin
complications of meningitis
sensorineural hearing loss
seizures, epilepsy
cognitive impairment, learning disability
memory loss
where do multiple abscesses tend to occur in the brain
at grey + white matter border
pyogenic meningitis
thick layer of supparative exudate cover leptomennges over the surface of brain
exudate in basal + convexity surface
neutrophils in subarachnoid space
listeria meningidis
gram pos
over 60s, alcoholic
Q will sound like meningitis but mention risk factor
steroids in meningococcal management
Give to all patients suspected of bacterial meningitis
o 10mg IV 15-20min before or with the first dose of antibiotic + then every 6hrs for 4d
Pneumococcal meningitis benefits the most from this
- DO NOT give in post surgical meningitis, severe immunocompromised, meningococcal, septic shock or hypersensitive to steroids
causes of viral meningitis
enteroviruses - coxsackie, echovirus
mups
herpes simplex virus, CMV, herpes zoster
HIV
measles
management of viral meningitis
CSF PCR to diagnose
self limiting, supportive treatment
aciclovir if secondary to HSV
encephalitis commonest cause
HSV-1 (cold sore)
- (HSV-2 in neonates)
(encephalitis = brain parenchyma inflamed)
presentation of encephalitis
fever, headache, psychiatric symptoms, seizures
focal features - aphasia
personality/behavioural change
(typically affect temporal + inferior lobes)
encephalitis MRI findings
medial temporal + inferior frontal changes (petechia haemorrhages)
management of encephalitis
pre-emptive aciclovir
cribiform plate fracture causing meningitis causative organism
strep pneumoniae
also hospitalised patients, diabetics, cochlear implants
who should undergo CT prior to lumbar puncture?
immunocompromised
history of CNS infection
new onset seizure
papillodema
abnormal level of consciousness
focal neurologic deficit
cryptococcal meningitis
fungal
subtle neurological presentation
aseptic picture on CSF
mainly in HIV - CD4<100
IV amphotericin B/flucytosine fluconazole
antibiotics for bacterial meningitis in penicillin allergy
chloramphenicol + dexamethosone
add co-trimoxazole if over 60
