CNS Infections Flashcards
CSF is normally ______ with very few ____ and low levels of __________ & __________.
sterile; WBCs; antibodies & complement.
What are the primary routes of infection of the CNS (3)?
Bloodstream/lymphatics.
Nerves.
Bones.
What are the 3 bacterial species causing most post-infancy meningitis cases?
Streptococcus pneumoniae.
Haemophilus influenzae type B.
Neisseria meningitidis.
What is the most common/important virulence factor for bacterial species causing meningitis?
Capsule.
Elevated CSF protein levels & decreased CSF glucose levels are signs of:
pyogenic (acute) meningitis.
A “positive” Gram stain or CSF culture indicates:
pyogenic (acute) meningitis (bacteria present).
Finding neutrophils in CSF would indicate:
pyogenic (acute) meningitis.
Finding lymphocytes or monocytes in CSF would indicate:
chronic meningitis.
A “negative” Gram stain result or CSF culture would indicate:
chronic meningitis.
What are 3 common infectious agents causing chronic meningitis?
Mycobacterium tuberculosis.
Listeria monocytogenes.
Viral agents.
Streptococcus pneumoniae meningitis has a very high _________ rate and the highest ____________ rate.
mortality; complication.
Streptococcus pneumoniae meningitis is often characterized by _____ onset.
acute.
What is the Gram morphology of H. influenzae?
G- bacilli.
H. influenzae meningitis is often characterized by _________ onset.
insidious (days).
What are some virulence factors of H. influenzae?
Capsule, IgA protease, pili, endotoxin & OMPs.
Neonatal meningitis is most commonly caused by (2);
- Streptococcus agalactiae (Group B).
2. E. coli.
What are some general symptoms of neonatal meningitis?
Fever, poor feeding, vomiting, respiratory distress, diarrhea.
What are 4 complications of neonatal meningitis?
Cerebral/cranial nerve palsy.
Epilepsy.
Mental retardation.
Hydrocephalus.
Viral meningitis is also known as:
acute aseptic meningitis (syndrome).
Viral meningitis is characterized by:
lymphocytic pleocytosis.
Viral meningitis is commonly caused by:
enteroviruses or Herpes viruses.
Botulism is caused by:
Clostridium botulinum.
Describe the Gram morphology & characteristic of C. botulinum.
Anaerobic, spore-forming G+ bacillus.
C. botulinum is normally found in:
soil & water sediments.
Botulinum toxin can be inactivated by:
boiling for 5 minutes.
Botulinum toxin primarily causes:
peripheral nerve paralysis.
How does botulinum toxin work?
It binds to neurons & prevents release of acetylcholine across the synaptic cleft.
What are 5 clinical symptoms of botulism?
Progressive flaccid paralysis (1-10 days). Nausea. Double vision. Difficulty swallowing. General weakness.
Infant botulism is often associated with:
infants under 1 year old consuming honey.
Why are infants particularly susceptible to botulism?
They lack stomach acidity and protective gut flora so spores can germinate easily.
What are 2 clinical symptoms of infant botulism?
Lethargy & constipation.
Infant botulism is treated with an:
antitoxin.
What kind of virus is polio?
Non-enveloped RNA enterovirus.
Where does polio virus multiply in the body?
The throat & small intestine.
Where does polio virus go to get into the blood & lymph?
Peyer’s patches in the intestine.
Describe abortive poliomyelitis.
Most common form of polio disease that resembles a minor, flu-like illness.
Describe non-paralytic poliomyelitis.
Minor flu-like symptoms + stiff neck/back (due to aseptic meningitis).
Paralytic poliomyelitis causes:
flaccid paralysis.
What are the 3 first symptoms of paralytic poliomyelitis?
Severe myalgia (pain) in one limb.
Motor/sensory disturbances.
Weakness.
Describe the 2 types of paralytic poliomyelitis.
- Bulbar: involves 1+ cranial nerve centres, including a respiratory sensory in the medulla oblongata (iron lung).
- Spinal: affects lower limbs.
How is polio virus transmitted?
Fecal-oral.
The Salk polio vaccine is an:
IPV: inactivated polio vaccine.
The Sabin polio vaccine is a:
live, attenuated oral vaccine.
Describe the virus that causes rabies.
Enveloped RNA rhabdovirus.
Rabies virus usually multiplies in ______ cells before travelling to the CNS via the ______.
muscle; nerves.
What is the average incubation period for rabies?
30-50 days.
What are 6 of the first symptoms of rabies?
Fever. Sore throat. Headache. Discomfort at sight of infection. Muscle spams. Convulsions.
Why is rabies also known as hydrophobia?
Swallowing muscles often spasm and can be triggered by the sight of water.
Describe the West Nile Virus.
Family: flaviviridae.
Small, enveloped RNA virus.
How is WNV transmitted?
Via mosquitoes with birds as reservoirs.
Humans and horses are considered __________ _____ for WNV.
incidental/accidental hosts.
Can WNV be transmitted from human to human?
No.
Complicated WNV disease usually affects:
the elderly, patients with preexisting chronic conditions & the immunocompromised.
Polio-like paralysis syndrome has recently emerged in ___ infections.
WNV.
Prions result in accumulation of _______ fibres in the nervous system and cause large holes in _____ tissue.
amyloid; brain.
What are some common examples of prion diseases?
Mad Cow Disease (BSE).
Scarpie (sheep).
Kuru (New Guinea: from cannibalism).
CJD/vCJD.
DEET containing repellents is used for what disease?
WNV disease
Is there a vaccine and antiviral for WNV disease?
no
Prions affect the ____ and _____.
brain; spinal cord
Scrapie is common in ___ and ____.
sheep and goats
vCJD affects what population the most?
younger patients
vCJD has a ____ duration of illness
longer
