ch 24

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ch 24
2011-04-19 18:44:32
infections cns

infections of the cns
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  1. How do bacterial and viral meningitis differ?
    • Bacterial meningitis can be very severe and cause brain damage, hearing loss, or learning disability.
    • Viral meningitis is less severe and usually resolves without treatmnet. It is caused by infection with one of several types of virus and is rarely fatal
  2. What are the most common cuses of bacterial meningitis?
    • Bacterial meningitis-- 5 species cause 90% of bacterial meningitis cases
    • streptococcus pneumoniae- leading cause in adults
    • neisseria menigitidis- due to fimbria, capsule, and lipooligosaccharide
    • haemophilus influenzae- leading cause prior to vaccine
    • listeria monocytogenes- disease in fetuses, prego women, and immunocompromised individuals
    • streptococcus agalactiae- causes most cases of new born meningitis (doesn’t occur often)
  3. What are the most common causes of viral meningitis?
    • Caused by infection with one of several types of virus
    • About 90% of the time it's enterovirus although herpes virus and mumps virus can also caus the disease.
  4. How does the tetanus toxin work?
    • The oxin produced by C. tetani is a neruogenic toxin, meaning that it has an affinity for and targets nervous tissue.
    • Called either tetanospasmin or tetanus toxin, it acts by enzymatically degrading proteins required for normal physiology in nervous tissue.
  5. The botulism toxin
    • This toxin is ingested as a preformed component and is ingested as a preformed component and is absorbed directlytherough the intestinal tract, reaching the neuromuscular junction target bia the bloodstream.
    • Once bound there, the toxin inhibits teh release of acetylcholine, causing muscular paralysis.
    • The symptoms observed depend on which nerves are bound by the toxin, and damage to the nerves after toxin has bound is permanent.
  6. What are the three forms of botulism?
    • food borne
    • infant
    • wound
  7. How is rabies treated
    • Prevention
    • Treatment consists of a course of injectios that are only beneficial if administered before the onset of symptoms
    • Intesnsive supportive care can result in longer-term survival
  8. Symptoms of rabies
    • A relentless progression of excess motor activity
    • Agitation
    • Hallucinations
    • Excessive slivation
    • Severe throat contraction when swallowing
    • The illness begins iwth nonspecific fevere, headache, malaise, nausea, and vomiting.
  9. What are the four types of poliomyelitis
    • abortive/asymptomatic infections- almost 90% of all cases
    • nonparalytic polio- stiff neck, muscle spasms and back pain
    • paralytic polio- produces paralysis; can be can systemic and can affect all muscle systems or just a few → death can occur due to lack of ability to breathe
    • post polio syndrome- condition that occurs 20-30-40 years after initial infection; not well understood; groups of muscles affected start to deteriorate (you don’t have the virus in your body anymore); your muscles atrophy and eventually there is no muscle left → no way to prevent it.
  10. Pathogen and pathogenesis of polio
    • Poliovirus is the causative agent
    • transmitted most often by drinking contaminated water
  11. Host/victim of EEE
    Horses and people
  12. Host/victim of WEE
    horses and people
  13. Host/victim of St. Louis encephalitis
    horses and humans
  14. host/victim of West Nile virus
    Horses, humans, birds
  15. Causitive agent of encephalitis
  16. Causitive agent of tetanus
    clostridium tetani
  17. Causitive agent of botulism
    clostridium botulinum
  18. Causitive agent of polio
  19. causitive agent of rabies
    rabies virus
  20. One of the most dangerous results of infectinon of the central nervous system is
    vasogenic edema
  21. Infections of the CNS can begin with?
    • Infections of the middle ear
    • Sinusitis
    • Mastoiditis
    • Pneumonia
  22. The clinical effects of botulism are caused by
  23. Antiobiotic therapy for tetanus would be
    Effective only if given early in the infection
  24. The symptoms of infant botulism include
  25. Prions are
  26. The urban forms of rabies is associated with
    Unimmunized dogs and cats