CNS Infection Flashcards
Symptoms of meningitis
Headache
Neck stiffness
Photophobia
Reduced consciousness level
Causative organisms of bacterial meningitis by age
neonates, children, adolescents, adults and elderly
Neonates
- listeria monocytogenes
- group B strep
- e coli
Children
- haemophilus influenzae
Adolescents
- nerisseria meningtidis
Adults
- strep pneumonia > neisseria meningtidis
Elderly
- strep pneumonia > listeria monocytogenes
Appearance of strep pneumoniae on gram stain.
Gram positive diplococcus
Who get strep pneumoniae meningitis?
Adults
Elderly
Skull fractures
How do bacteria get to the meninges to cause meninigitis?
What is the clinical relevance of this?
Haematogenous spread from nasopharynx
Previous sinusitis can break down mucosa allowing spread of bacteria
Appearance of neisseria meningtidis on gram stain.
Gram negative diplococcus
Who gets neisseria meningtidis meningitis?
Adolescents
second most common in adults/elderly
Appearance of listeria monocytgenes on gram stain.
Gram positive bacillus
Who gets listeria monocytogenes meningitis?
Neonates and elderly
Immunocompromised
Patient presents to GP with non-blanching rash, fever, neck stiffness, photophobia.
Immediate management?
IM benzylpenicillin and immediate transfer to hospital
What organism causes non-blanching rash in meningitis?
Neisseria meningtidis
meningococcal
What antibiotic regimen do you use for bacterial meningitis?
IV ceftriaxone
What antibiotic regimen do you use for bacterial meningitis if
- penicillin allergic
- > 60/immunocompromised
- recent travel?
Penicillin allergy: chloramphenicol
> 60/immunocompromised: amoxicillin (co-trimoxazole if penicillin allergic)
Recent travel: add vancomycin
What should be given with antibiotics in bacterial meningitis and in what scenario?
Why?
IV dexamethasone until pneumococcus ruled out
Reduces inflammation and neurological complications
What antibiotics should you give those in close contact with someone in meningitis?
Rifampacin 4 doses
Ciprofloxacin/ceftriaxone single dose
What is the commonest causative organism of viral meningitis?
Coxsackie/echovirus
What organism causes severe viral meningitis?
Herpes simplex virus
Varicella zoster
How do you manage viral meningitis?
Supportive
Unless HSV/varicella zoster where IV acyclovir
Presentation of tuberculous meningitis.
Starts as non-specific illness in elderly/immunocompromised/travel history which progresses to a classical meningitis
LP findings in bacterial meningitis.
Cloudy appearance
High neutrophils
Low glucose
LP findings in viral meningitis.
Clear appearance
High lymphocytes
Normal glucose
LP findings in tuberculous meningitis.
Clear appearance (forms fibrin web)
High lymphocytes
Low glucose
How do you differentiate viral meningitis from bacterial on LP
Appearance: bacterial would be cloudy and viral would be clear
Cell type: bacterial has neutrophils and viral and lymphocytes
Glucose: bacterial has low glucose and viral has normal glucose
How do you differentiate bacterial and tuberculous meningitis on LP?
Appearance: bacterial would be cloudy, tuberculous may form fibrin web
Cell type: bacterial as neutrophils and viral has lymphocytes
Glucose: both have low glucose
