Poliovirus

Question 1

Poliovirus is a member of what family?

Answer 1

Picornaviridae

Question 2

What other viruses are picornaviridae?

Answer 2

common cold and hepatitis

Question 3

What is the genus of poliovirus?

Answer 3

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

Question 4

poliovirus morphology>

Answer 4

nonenveloped icosahedral capsule

Question 5

WHat major symptoms does polio cause

Answer 5

flaccid paralysis called poliomyelitis

Question 6

How many annual cases of polio worldwide

Answer 6

less than 1,000

Question 7

Polio has been absent from US since>

Answer 7

1977

Absent from western hemisphere since 1994

Question 8

Polio reservoirs?

Answer 8

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

Question 9

Initial replication of poliovirus occurs where?

Answer 9

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

Question 10

Virus spreads to CNS and does what

Answer 10

destroys motor neurons

Question 11

90% of polio infections are…

Answer 11

subclinical

Question 12

Three types of disease caused by poliovirus

KNOW

Answer 12

• 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

Question 13

Importance of secretory IgA immune response?

Answer 13

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

Question 14

Post-polio syndrome

Answer 14

increased weakening of muscles later in life

Question 15

polio diagnosis

Answer 15

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

Question 16

Polio is best inactivated with?

Answer 16

formaldehyde or chlorine

Question 17

Poliovirus is resisitant to?

Answer 17

ethanol and detergents

Question 18

Us recommends use of what vaccine

Answer 18

inactivated

Question 19

inactivated vaccine called

Answer 19

Salk IPV

Advantage is that the inactivation prevents reversion to virulence

Question 20

Disadvantages of the Salk IPV

Answer 20

• 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

Question 21

DO not use Salk IPV if allergic to

Answer 21

neomycin, streptomycin, or polymyxin B

Question 22

Oral vaccine

Answer 22

Sabin opv

Question 23

Advantages to Sabin OPV

Answer 23

cheap, oral admin, protects against paralysis and spread

Question 24

Disadvantge of oral vaccine

Answer 24

Can revert to virulence during preparation or during shedding by participants