viral gastroenteritis

Question 1

viruses are..

Answer 1

obligate IC pathogens

Question 2

viruses infect ??

thereby messing up ??

causing what type of diarrhea ??

Answer 2

enterocytes in the villi of the sm. intestine

disrupting both digestive and absorptive functions

osmotic diarrhea from inability to digest disaccharides

Question 3

viruses transmitted via

Answer 3

fecal-oral route, but food and water can be major vehicles

Question 4

virus clinical features

fever?

Answer 4

vomiting, diarrhea, abdominal pain
fever
some (norwalk, norovirus): ha and myalgias

Question 5

virus dx

Answer 5

immunoassay or electron microscopy: RT-PCR (for Norovirus)

Question 6

virus tx

Answer 6

supportive, fluid replacement (esp infants)

Question 7

virus: vaccines?

Answer 7

for Rotavirus:
Tetravalent Rhesus Rotavirus-based Reassortant Live Oral Vaccine (RV-TV, Rotateq -Merck)

Wyeth’s vaccine no longer used: intussusception

Question 8

virus prevention

Answer 8

soap and water > etOH hand san (Norovirus)

Question 9

Rotavirus

Answer 9

dsRNA, segmented genome, serotypes (A* (US),B,C)

Question 10

rotavirus vir. factor

Answer 10

enterotoxin NSP4: nonstruc. glycoprotein (diff. rec. w. age)

Question 11

rotavirus immunogenic component of vaccine

Answer 11

G glycoprotein (G1-G4)-tetravalent also used to serotype virus

Question 12

most common cause of sev. diarrhea in infants and young kiddos

Answer 12

rotavirus

(maj. cause infant mort., 3% hospitalizations

Question 13

how is rotavirus spread?

can last for days-weeks where?

Answer 13

person-person
-asymptomatic carriage is important
on surfaces (changing diapers)

Question 14

is rotavirus low or high dose organism?

Answer 14

LOW! mountain range–propagated

Question 15

rotavirus presentation

how long?

Answer 15

dehydrating diarrhea, vomiting, fever, abd pain
5-7 days
(use BRAT diet)

Question 16

norovirus

evolving?

Answer 16

ssRNA small, round, structured virus 
7 genogroups (30 genotypes) 
new pandemic strain emerges every 2-4 yrs!

Question 17

noroviruses recognize..

Answer 17

histo-blood group Ags in strain-sp. manner

ABO, Lewis and secretor families involved in norovirus binding

Question 18

this gene ??? is determines susc. to norovirus infection

Answer 18

fucosyltransferase 2 (FUT2) gene

Question 19

ppl with this trait ?? are resistant to norwalk virus

Answer 19

nonsecretors (20% Europeans)

Question 20

norovirus shares characteristics with

Answer 20

norwalk virus

Question 21

most common cause of infectious GE in all ages?

responsible for 50% of ??
80% of non-food-borne outbreaks occur where ???

Answer 21

norovirus
also universal among children
all food-borne GE outbreaks in US
nursing homes, long-term care settings
also hospitals

Question 22

setting for 2/3 of norovirus FB outbreaks?

Answer 22

restaurants, then banquet and catering sites

Question 23

1% non-food borne norovirus outbreaks attrib. to

Answer 23

cruise ships

Question 24

norovirus: low or high dose?

spread how??

Answer 24

low (10 virions)
spread aerosolized (vomit)

Question 25

what virus resistant to chlorination and freezing and persists in the environment

Answer 25

norovirus

Question 26

norovirus inf individuals are highly contagious for how long??
virus can be shed up to ?? post recovery

Answer 26

72 hrs post recovery (3 days)

2 wks

Question 27

norovirus immunity last ??

Answer 27

2-3 yrs

Question 28

norovirus onset?

Answer 28

12-48 hr incubation period (1/2 day to 2 days)

Question 29

norovirus presents with ??

how long??

Answer 29

epidemic vomiting syndrome: acute vomiting*, diarrhea, *fever (low-grade), myalgia, ha
1-2 days

Question 30

Kaplan’s criteria for dx viral GE outbreak

Answer 30

1. mean/median illness duration of 12-60 hrs (0.5-2.5 days)
2. mean/median incubation period of 24-48 hrs (1-2 days)
3. > 50% ppl with vominting
4. no bac agent previously found

Question 31

norovirus dx

Answer 31

RT-PCR

Question 32

Norwalk virus

Answer 32

ssRNA; 2 serotypes

Question 33

norwalk virus causes what ??
in who??
but…

Answer 33

epidemics of vomiting and diarrhea
older children in adults
all ages are affected

Question 34

norwalk virus occurs when??

associated with ??

Answer 34

summer

shellfish, other food, water is a common vehicle

Question 35

Norwalk virus occurs in what groups?

Answer 35

community-wide outbreaks, families

nursing homes

Question 36

norwalk virus presentation

duration?

Answer 36

acute vomiting, diarrhea, fever, myalgia and ha

1-2 days

Question 37

enteric adenovirus
causes what in who ??
seasonality??

Answer 37

dsDNA
enteric diarrhea of infants and young children
no seasonality here

Question 38

enteric adenovirus presentation

duration

Answer 38

prolonged diarrhea
5-12 days
vomiting and fever