Enteric Viruses 1 (7)

Question 1

How is the virology of picornaviruses, noroviruses, rotaviruses similar?

Answer 1

small, naked, icosahedral RNA viruses

Question 2

What type of genome does rotavirus have? why is it’s capsid special?

Answer 2

segmented

capsid is double layered

Question 3

Why is infection with rotavirus dangerous?

Answer 3

dehydration from diarrhea

Question 4

What are the sequelae of rotavirus infection?

Answer 4

none

Question 5

How long does an infection with rotavirus usually last?

Answer 5

5 days

Question 6

Describe the disease norovirus causes

Answer 6

short but rough bout of vomiting and diarrhea

~48 hours

Question 7

Why does norovirus tend to have less dehydration than rotavirus?

Answer 7

tends to affect older patients and has a shorter course

Question 8

Is there a vaccine available for rotavirus or norovirus?

Answer 8

only rotavirus - not required but is available

Question 9

Enteroviruses, a subset of picornaviruses, do their main replication where? If viremia occurs, where does replication occur?

Answer 9

main - GUT

viremia - LNs

Question 10

What is the most effective way to prevent infection with all picornavirus, rotavirus, norovirus?

Answer 10

washing your hands

Question 11

How are the three viruses able to be transmitted fecal orally?

Answer 11

all environmentally rugged

Question 12

> 90% of enteroviruses resolve asymptomatically, what happens to the other 10%? why ?

Answer 12

invasion of the CNS

CD155 receptor is common to gut lymph and gray matter

Question 13

How does the enterovirus enter the CNS?

Answer 13

by crossing the BBB or retrograde axonal transport from periphery

Question 14

Where is the main location in the CNS that enteroviruses like to infect? what results therefore?

Answer 14

anterior motor horns

flaccid asymmetric weakness and/or resp. failure

Question 15

Why are we able to make a vaccine for poliovirus (a type of enterovirus)?

Answer 15

humans are the only host - so we are able to erradicate!

Question 16

What are some risk factors for CNS progression of the poliovirus?

Answer 16

• immunosuppression
• pregnancy
• tonsilectomy
• advanced or young age
• recent hard exercise

Question 17

What type of vaccine for the poliovirus do we use here? what type do we use in the developing world?

Answer 17

here - inactivated

developing world - attenuated

Question 18

What is the main risk of the attenuated polio vaccine?

Answer 18

if patient or contact is immunosuppressed is infected with another enterovirus - at risk for genetic exchange to occur and they may get polio-like symptoms

Question 19

What is the treatment for polio?

Answer 19

supportive care and physical therapy - need to train muscles