Chapter 22 Flashcards
What are the four bacteria that commonly cause meningitis?
- Streptococcus pneumoniae
- Neisseria meningitidis
- Haemophilus influenza type B (Hib)
- Listeria monocytogenes
What are some of the characteristics that these different pathogens have in common?
Capsule formation for protection
Ability to invade the central nervous system (CNS)
Release of cell wall fragments
Association with meningitis and potential neurological damage
Which type of meningitis is more common in college-aged students?
Neisseria meningitidis (meningococcal meningitis)
Which meningitis bacterial type can be transferred from mother to fetus?
Listeria monocytogenes
What is a critical symptom of meningitis?
Symptoms include:
- A bloody and cloudy cerebrospinal fluid (CSF)
- High white blood cell count
- Inflammation of the meninges
How do viral and bacterial meningitis compare?
- Viral meningitis is more common and tends to be milder than bacterial meningitis.
- Bacterial meningitis is often more severe and can be life-threatening.
Is botulism caused by the organism itself or a released toxin?
Botulism is caused by the released toxin produced by Clostridium botulinum.
What type of paralysis is caused by botulism?
Flaccid paralysis
What is the connection with babies, honey, and botulism?
Infants under 1 year old should not be given honey, as it may contain spores of Clostridium botulinum, which can lead to botulism in infants.
What are some major misconceptions of leprosy?
- That it’s highly contagious (it is not)
- That it causes body parts to fall off (it does not)
What is the alternate term for leprosy?
Hansen’s disease
Where does leprosy grow in the human body?
Leprosy grows in the peripheral nervous system (PNS)
How do immune responses contribute to the pathogenesis of leprosy?
The cell-mediated immune response can lead to nerve damage in leprosy.
Is tetanus caused by the organism itself or a released toxin?
Tetanus is caused by the released toxin produced by Clostridium tetani.
What toxin is released from Clostridium tetani?
Tetanospasmin
How does the toxin (tetanospasmin) affect a person?
Tetanospasmin blocks the relaxation pathway, causing muscle spasms, lockjaw, and opisthotonos.
How is polio commonly transmitted to a new host?
Poliovirus is commonly transmitted through contaminated water, often ingested.
How do most infections with polio affect the host?
Most infections with poliovirus are asymptomatic or exhibit mild symptoms. Fewer than 1% result in paralysis.
What is the chance that infection with poliovirus will result in paralysis?
Less than 1%
Which body structure is completely paralyzed by a severe polio infection?
Lungs
What is the only disease studied in this chapter that is susceptible to vaccination after the initial exposure?
Polio can be prevented by vaccination even after the initial exposure.
What is hydrophobia?
Hydrophobia is a symptom of rabies, where the sight or thought of water triggers spasms due to difficulty swallowing.
How is dumb rabies distinct from classical rabies?
- Furious (classic) rabies
1. Biting behavior
2. When paralysis occurs- flow of saliva increases
3. Fatal in a few days - Paralytic (dumb or numb) rabies
1. Minimal excitability
2. Common in cats- quiet, unaware of surroundings
3. Often misdiagnosed in humans as Guillain-Barre Syndrome (form of paralysis)
What general type of animal is more likely to show dumb rabies?
Cats are more likely to show dumb rabies.
What is the vector for arboviral encephalitis?
Mosquitoes
How can Zika virus spread person to person?
Zika virus can be sexually transmitted, during pregnancy and delivery, and through blood transfusions.
When is Zika the most severe?
Zika is most severe when transmitted during pregnancy, potentially leading to microcephaly in infants.
What is the etiology of cryptococcosis?
Crytpococcosis is caused by a fungus that grows in the CNS
How is Cryptococcus neoformans transmitted?
Transmission occurs through inhalation of dried, contaminated droppings.
Where is Cryptococcus neoformans commonly found?
Found in areas with bird droppings, particularly in pigeon droppings.
