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Flashcards in viral gastroenteritis Deck (38)
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1
Q

viruses are..

A

obligate IC pathogens

2
Q

viruses infect ??

thereby messing up ??

causing what type of diarrhea ??

A

enterocytes in the villi of the sm. intestine

disrupting both digestive and absorptive functions

osmotic diarrhea from inability to digest disaccharides

3
Q

viruses transmitted via

A

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

4
Q

virus clinical features

fever?

A

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

5
Q

virus dx

A

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

6
Q

virus tx

A

supportive, fluid replacement (esp infants)

7
Q

virus: vaccines?

A

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

Wyeth’s vaccine no longer used: intussusception

8
Q

virus prevention

A

soap and water > etOH hand san (Norovirus)

9
Q

Rotavirus

A

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

10
Q

rotavirus vir. factor

A

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

11
Q

rotavirus immunogenic component of vaccine

A

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

12
Q

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

A

rotavirus

(maj. cause infant mort., 3% hospitalizations

13
Q

how is rotavirus spread?

can last for days-weeks where?

A
person-person
-asymptomatic carriage is important
on surfaces (changing diapers)
14
Q

is rotavirus low or high dose organism?

A

LOW! mountain range–propagated

15
Q

rotavirus presentation

how long?

A

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

16
Q

norovirus

evolving?

A
ssRNA small, round, structured virus 
7 genogroups (30 genotypes) 
new pandemic strain emerges every 2-4 yrs!
17
Q

noroviruses recognize..

A

histo-blood group Ags in strain-sp. manner

ABO, Lewis and secretor families involved in norovirus binding

18
Q

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

A

fucosyltransferase 2 (FUT2) gene

19
Q

ppl with this trait ?? are resistant to norwalk virus

A

nonsecretors (20% Europeans)

20
Q

norovirus shares characteristics with

A

norwalk virus

21
Q

most common cause of infectious GE in all ages?

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

A
norovirus
also universal among children
all food-borne GE outbreaks in US
nursing homes, long-term care settings
also hospitals
22
Q

setting for 2/3 of norovirus FB outbreaks?

A

restaurants, then banquet and catering sites

23
Q

1% non-food borne norovirus outbreaks attrib. to

A

cruise ships

24
Q

norovirus: low or high dose?

spread how??

A
low (10 virions)
spread aerosolized (vomit)
25
Q

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

A

norovirus

26
Q

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

A

72 hrs post recovery (3 days)

2 wks

27
Q

norovirus immunity last ??

A

2-3 yrs

28
Q

norovirus onset?

A

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

29
Q

norovirus presents with ??

how long??

A

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

30
Q

Kaplan’s criteria for dx viral GE outbreak

A
  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
31
Q

norovirus dx

A

RT-PCR

32
Q

Norwalk virus

A

ssRNA; 2 serotypes

33
Q

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

A

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

34
Q

norwalk virus occurs when??

associated with ??

A

summer

shellfish, other food, water is a common vehicle

35
Q

Norwalk virus occurs in what groups?

A

community-wide outbreaks, families

nursing homes

36
Q

norwalk virus presentation

duration?

A

acute vomiting, diarrhea, fever, myalgia and ha

1-2 days

37
Q

enteric adenovirus
causes what in who ??
seasonality??

A

dsDNA
enteric diarrhea of infants and young children
no seasonality here

38
Q

enteric adenovirus presentation

duration

A

prolonged diarrhea
5-12 days
vomiting and fever

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