Viral GI infections

Question 1

4 causes of viral gastroenteritis, type of infection

Answer 1

rota, noro, astro, adenovirus

usually localized infection

Question 2

rotavirus infection, transmission

Answer 2

2 day incubation, low grade fever, emesis and diarrhea

large amount of virus in stool

spreads b/w people, often in daycares, nursing homes, etc

Question 3

toxin from rotavirus

Answer 3

protein NSP4 acts like enterotoxin, affects Ca++ infux

Question 4

Dx, Rx, prevention of rotavirus

Answer 4

Dx- stool enzyme immunoassay or PCR

Rx- rehydration

prevention- hygiene, vaccine given orally

Question 5

norovirus viral type

Answer 5

calicivirus- small spherical, no envelope

Question 6

norovirus disease

Answer 6

acute 2-3 day illness- nausea, emesis, cramps, diarrhea

systemic sx not from viremia

Question 7

norovirus outbreaks and Rx

Answer 7

close quarters, Rx w/ rehydration

Question 8

EM appearance of astrovirus

Answer 8

star like appearance- rarely need rx

Question 9

adenovirus serotypes in GI

Answer 9

40,41

Question 10

adenovirus viral type

Answer 10

dsDNA, icosahedral, no envelope

Question 11

main enterovirus

Answer 11

polio

Question 12

clinical pres of polio

Answer 12

most are asymptomatic, many have mild disease and quickly resolve

some cause mild meningitis

some cause poliomyelitis- inflammation of gray matter in spinal cord causing paralysis

Question 13

Salk vaccine

Answer 13

inactivated polio vaccine- good IgG response but no IgA respones

protect against paralysis, not infection (who could then spread virus)

Question 14

Sabin oral polio vaccine result

Answer 14

live vaccine replicates in oropharynx and gut, then disseminates

causes both IgA and IgG response

live virus shed in feces, no longer used in US

Question 15

spread of non polio enteroviursis

Answer 15

found in water supplies like water sewage

all ages, usually summer to fall