ID - Meningitis Flashcards
What type of bacteria is Neisseria meningitidis?
Gram-negative diplococcus
Commonly known as meningococcus
What causes a non-blanching rash?
Meningococcal sepsis that has caused disseminated intravascular coagulopathy and subcutaneous haemorrhages
What is meningococcal meningitis?
Bacteria infects meninges and CSF around brain and spinal cord
What are the most common causes of bacterial meningitis in children and adults?
Neisseria meningitidis
Streptococcus pneumoniae
What is the most common cause of bacterial meningitis in neonates?
Group B streptococcus
How is Group B strep usually contracted in neonates?
During birth
GBS usually live harmlessly in the vagina
How does meningitis present?
Neck stiffness
Photophobia
Altered consciousness
Seizures
Fever
Vomiting
Headache
How does meningitis present in neonates and babies?
Non-specific signs and symptoms
- Hypotonia
- Poor feeding
- Lethargy
- Hypothermia
- Bulging fontanelle
When is an LP recommended for children?
- Under 1 month with fever
- 1-3 months with fever and unwell
- Under 1 with unexplained fever and other features of serious illness
What are the two special tests for meningitis in children and what do they involve??
Kernig’s test
- Lay patient on back
- Flex one hip and knee to 90 degrees then straighten knee while hip flexed at 90 degrees
- Creates slight meninges stretch causing pain or resistance to movement
Brudzinski’s test
- Lay patient on back
- Gently lift head and neck and flex chin to chest
- Patient will involuntarily flex hips and knees
How is bacterial meningitis or meningococcal sepsis managed in the community?
If suspected meningitis and non-blanching rash
Urgent IM Benzylpenicillin prior to hospital transfer
If penicillin allergy, transfer should be prioritised over alternative
How is bacterial meningitis or meningococcal sepsis managed in hospital?
Ideally blood culture and LP performed before antibiotics
If patient acutely unwell do not delay antibiotics
Meningococcal PCR, tests directly for meningococcal DNA
Low threshold for treatment particularly in babies and young kids
Under 3 months
Cefotaxime + amoxicillin (covers listeria contracted in pregnancy)
Over 3 months
Ceftriaxone
When should vancomycin be added to antibiotic treatment for meningitis?
Risk of penicillin resistant pneumococcal infection e.g. recent foreign travel or prolonged antibiotic use
Why are steroids also used in bacterial meningitis?
Reduce frequency and severity of hearing loss and neurological damage
Dexamethasone given 4 times daily for 4 days to children over 3 months if LP suggests bacterial meningitis
What must be done with all bacterial meningitis and meningococcal infections?
Notifiable disease
Public health must be informed
When is risk of transmission highest for meningococcal infections?
Close prolonged contact within 7 days prior to illness onset
Risk decreases 7 days after exposure, if no symptoms, unlikely to develop illness
What post exposure prophylaxis is used for meningococcal infections?
Single dose of ciprofloxacin
Given as soon as possible and within 24 hours of initial diagnosis
What are the most common causes of viral meningitis?
Herpes simplex virus
Enterovirus
Varicella zoster virus
CSF sample should be sent for viral PCR testing
How is viral meningitis tested?
Tends to milder than bacterial and usually only needs supportive treatment
Aciclovir can be used to treat suspected HSV or VZV
Where is an LP inserted?
L3-L4 as spine ends at L2
Use the Iliac crest as a guide
What layers are passed through in an LP?
SSS ILE DAS
Skin
Subcutaneous fat
Supraspinous ligament
Intraspinous ligament
Ligamentum flavum
Epidural space
Dura mata
Arachnoid mata
Subarachnoid space
What is CSF tested for?
Bacterial culture
Viral PCR
Cell count
Protein
Glucose
What should be sent at the same time to be compared to CSF?
Blood glucose
Fill in the table
Viruses don’t use glucose but bacteria will use it and release proteins
What are the key complications of meningitis?
Hearing loss
Seizures and epilepsy
Cognitive impairment and learning disability
Memory loss
Cerebral palsy with focal neurological deficits e.g. limb weakness or spasticity
