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Neurology > Poliovirus > Flashcards

Flashcards in Poliovirus Deck (24)
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1
Q

Poliovirus is a member of what family?

A

Picornaviridae

2
Q

What other viruses are picornaviridae?

A

common cold and hepatitis

3
Q

What is the genus of poliovirus?

A

Enterovirus- which means it spreads via fecal/oral route and replicates in the GI tract

4
Q

poliovirus morphology>

A

nonenveloped icosahedral capsule

5
Q

WHat major symptoms does polio cause

A

flaccid paralysis called poliomyelitis

6
Q

How many annual cases of polio worldwide

A

less than 1,000

7
Q

Polio has been absent from US since>

A

1977

Absent from western hemisphere since 1994

8
Q

Polio reservoirs?

A

Humans only…this combined with the few number of serotypes makes it easy to vaccinate agianst

9
Q

Initial replication of poliovirus occurs where?

A

Lymphoid tissue of pharynx and gut. So the virus is present in the throat and the feces

10
Q

Virus spreads to CNS and does what

A

destroys motor neurons

11
Q

90% of polio infections are…

A

subclinical

12
Q

Three types of disease caused by poliovirus

KNOW

A
  • Abortive poliomyelitis- mild illness
  • Aseptic meningitis- only 1-2% of those infected
  • Paralytic poliomyelitis- risk increases with age, can affect just about any musculature, any paralysis after 6 months is permanent
13
Q

Importance of secretory IgA immune response?

A
  • Secreted by the gut, neutralizes the virus before it can be shed and thus can prevent spread of virus
14
Q

Post-polio syndrome

A

increased weakening of muscles later in life

15
Q

polio diagnosis

A

specimen collection from stool, rectal swabs, throat swabs, etc…

  • neutralization assays are performed to confirm poilio
  • vaccine strains distinguished from wild strains using specific antibodies
16
Q

Polio is best inactivated with?

A

formaldehyde or chlorine

17
Q

Poliovirus is resisitant to?

A

ethanol and detergents

18
Q

Us recommends use of what vaccine

A

inactivated

19
Q

inactivated vaccine called

A

Salk IPV

Advantage is that the inactivation prevents reversion to virulence

20
Q

Disadvantages of the Salk IPV

A
  • Takes four subcutaneous injections

- Protects against paralysis but not the spread of wild virus because soince it is subcu, you get a good IgG but no IgA

21
Q

DO not use Salk IPV if allergic to

A

neomycin, streptomycin, or polymyxin B

22
Q

Oral vaccine

A

Sabin opv

23
Q

Advantages to Sabin OPV

A

cheap, oral admin, protects against paralysis and spread

24
Q

Disadvantge of oral vaccine

A

Can revert to virulence during preparation or during shedding by participants