Microbiology - CNS Infection + Meningitis Flashcards
What is meningitis?
Inflammation of the meninges
What is meningism?
- Stiff neck
- Rash
- Headache
What are some bacterial causes of meningitis?
Adults:
- Neisseria meningitides (Gram -ve)
- Streptococcus pneumoniae (Gram +ve)
Neonates:
- Group B strep
- Listeria monocytogenes
- E. coli
Elderly:
- Group B strep
- Listeria monocytogenes
What are some viral caues of meningitis?
- Enterovirus (Coxsackie, echovirus)
- Mumps
- HSV2
What are some fungal causes of meningitis?
Cryptococcus neoformans
How does Chronic/subacute meningitis present and what are its causes?
- Headaches for months
Causes:
- TB
- Cryptococcus
What are some causative organisms for meningitis in an immunocompromised patient?
- TB
- Cryptococcus Gattii
What is encephalitis?
Inflammation of the brain parenchyma
What are some symptoms of encephalitis?
- Confusion
- Fluctuating consciousness
- Systemically unwell
- Altered mental state
What is the most common UK causes of encephalitis?
HSV1
What is the management for encephalitis?
IV acyclovir
What is a brain abscess?
A localised collection of infection in the brain parenchyma
What are some symptoms of a brain abscess?
- Same as SOL
- Swinging fever
How is a brain abscess caused?
- From local extension (e.g. otitis media)
- Haematogenous spread (e.g. endocarditis)
What are some common causative organisms of a brain abscess?
- Staphylococcus
- Strep
- Anaerobes
What is a common causative organism of a brain abscess in an HIV patient?
Toxoplasmosis
How is a brain abscess diagnosed?
MRI with contrast (RING-ENHANCING LESION)
What is the management of a brain abscess?
- Abx: wide-spectrum + anaerobe coverage
- Surgical drainage
- ?Steroids + anti-seizure medication
What are some general RFs for bacterial meningitis?
- Overcrowding
- Young adults/Very young OR Old
What are some RFs for a bacterial meningitis caused by N. meningitides?
- Complement deficiency
- Hyposplenism (susceptible to encapsulated organisms)
- Hypogammaglobinaemia
What are some RFs for a bacterial meningitis caused by S. pneumoniae?
- Complement deficiency
- Hyposplenism
- Immunosuppressed (Alcoholic)
- Infection (pneumonia)
- Previous head trauma with CSF leak
What are some symptoms of a bacterial meningitis?
- Headache
- Vomiting
- Photophobia
- Fever
- Focal neuro signs
- Rash (meningococcal)
How is bacterial meningitis diagnosed?
- Clinical Dx + cultures
- Lumbar puncture for CSF analysis
What is the management for bacterial meningitis?
- Resuscitate
- IV ceftriaxone
- Corticosteroids
(Cover Listeria with ampicillin)
IF consciousness affected:
-? IV acyclovir (enecephalitis cover)
GP Tx:
- IM Benzylpenicillin + Ambulance
What is seen on the CSF of a patient with bacterial meningitis?
(Appearance, opening pressure, WBC, glucose level, protein level)
Appearance: Cloudy + TURBID
Opening Pressure: Elevated
WBC: Elevated (POLYMORPHS)
Glucose Level: LOW
Protein Level: Elevated
What is seen on the CSF of a patient with viral meningitis?
(Appearance, opening pressure, WBC, glucose level, protein level)
Appearance: Clear
Opening Pressure: Normal/Elevated
WBC: Elevated (MONONUCLEAR - lymphocytes)
Glucose Level: Normal
Protein Level: Elevated
What is seen on the CSF of a patient with Fungal meningitis?
(Appearance, opening pressure, WBC, glucose level, protein level)
Appearance: Clear or Cloudy (Fibrin web in TB)
Opening Pressure: Elevated
WBC: Elevated (Mononuclear in TB)
Glucose Level: LOW
Protein Level: Elevated
