CNS infections Flashcards
What is the most common anti-viral?
Aciclovir
What are the most common meningitis causing organisms?
Neisseria meningitidis
Haemophilus influenzae
Streptococcus pneumoniae
(herpes simplex virus)
What type of organism is neisseria meningitidis?
- gram negative coccus bacteria
- commensal organism in upper respiratory tract
How is neisseria meningitidis spread?
person to person
What type of organism is Haemophilus influenzae?
- gram negative cocco-bacillus
- commensal organism in upper respiratory tract
What structure do lots of CNS infections possess?
capsule to protect themselves against immune system
What type of organism is Streptococcus pneumoniae?
gram postitive diplococcus
What are the most common meningitis causing organisms in neonates?
- Listeria monocytogenes
- E.Coli
- streptococcus agalacticae (group B streptococcus)
How is listeria monocytogenes spread?
- can colonise food and vagina
- can therefore be transmitted to baby at birth
What other organisms can cause meningitis in immunocompromised patients?
- cryptococcus neoformans (yeast)
- Toxoplasma gondii (protozoa)
- Listeria monocytogenes (food borne)
What viruses can cause encephalitis?
- Herpes simplex virus
- Varicella-zoster virus
almost always these^
- polio, measles and mumps (vaccine preventable)
- zoonotic and vector borne (rabies, zika and Japanese encephalitis)
What are the symptoms of meningtis?
Headache fever neck stiffness photophobia non-blanching purpuric rash
What are the symptoms of meningtis?
- Headache
- fever
- neck stiffness
- photophobia
- non-blanching purpuric rash
What are the symptoms of progressed meningitis infection?
- neurological deficits
- upper respiratory tract symptoms
- AKI, disseminated intravascular coagulation
- shock, peripheral ischemia
What is the diagnostic approach for meningitis?
- antibacterials given even before culture
- imaging to check for raised intracranial pressure
- lumbar puncture (only if no intracranial pressure) check cell count, chemistry and microbiology
- blood culture
- throat swob, blood and CSF
What is the treatment of meningitis?
- ceftriaxone
- steroids to reduce pressure
- amoxicillin to cover listeria
- ciprofloxacin to eradicate carriage
What medication is given to treat meningitis in neonates?
cefotaxime
What are the symptoms of encephalitis?
- altered behaviour
- altered consciousness
- neurological symptoms
- fever
- rash for VZV
How is encephalitis diagnosed?
- CT and MRI
- Lumbar puncture
- PCR from throat, blood and CSF
- EEG
How is encephalitis treated?
- sedation if agitated
- ventilation if in coma
- hydration
- seizure management
- osmotherapy for raised intracranial pressure
- steroids to reduce pressure
- antivirals
What is the MoA of aciclovir?
- prodrug (only activated in virally infected cells)
- competitively inhibits DNA synthesis by competing with deoxyguanosine
- get aciclovir in DNA chain instead of deoxyguanosine which will terminate the chain
What are the side effects of aciclovir?
disturbances
- GI
- Skin
- neurological
- renal
What is aciclavir used for?
- Herpes labialis (lips) and eye infections
- orally for Herpes genital infections and varicella virus
- IV for life threatening HSV and VSV
Which drug can be given instead of aciclavir?
valaciclovir - easier to give orally
What antiviral can be used to treat cytomegalovirus?
Ganciclovir
