viral gastroenteritis Flashcards Preview

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Flashcards in viral gastroenteritis Deck (38):
1

viruses are..

obligate IC pathogens

2

viruses infect ??

thereby messing up ??

causing what type of diarrhea ??

enterocytes in the villi of the sm. intestine

disrupting both digestive and absorptive functions

osmotic diarrhea from inability to digest disaccharides

3

viruses transmitted via

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

4

virus clinical features
fever?

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

5

virus dx

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

6

virus tx

supportive, fluid replacement (esp infants)

7

virus: vaccines?

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

Wyeth's vaccine no longer used: intussusception

8

virus prevention

soap and water > etOH hand san (Norovirus)

9

Rotavirus

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

10

rotavirus vir. factor

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

11

rotavirus immunogenic component of vaccine

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

12

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

rotavirus
(maj. cause infant mort., 3% hospitalizations

13

how is rotavirus spread?

can last for days-weeks where?

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

14

is rotavirus low or high dose organism?

LOW! mountain range--propagated

15

rotavirus presentation
how long?

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

16

norovirus

evolving?

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

17

noroviruses recognize..

histo-blood group Ags in strain-sp. manner
ABO, Lewis and secretor families involved in norovirus binding

18

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

fucosyltransferase 2 (FUT2) gene

19

ppl with this trait ?? are resistant to norwalk virus

nonsecretors (20% Europeans)

20

norovirus shares characteristics with

norwalk virus

21

most common cause of infectious GE in all ages?

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

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

22

setting for 2/3 of norovirus FB outbreaks?

restaurants, then banquet and catering sites

23

1% non-food borne norovirus outbreaks attrib. to

cruise ships

24

norovirus: low or high dose?
spread how??

low (10 virions)
spread aerosolized (vomit)

25

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

norovirus

26

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

72 hrs post recovery (3 days)

2 wks

27

norovirus immunity last ??

2-3 yrs

28

norovirus onset?

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

29

norovirus presents with ??

how long??

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

30

Kaplan's criteria for dx viral GE outbreak

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

norovirus dx

RT-PCR

32

Norwalk virus

ssRNA; 2 serotypes

33

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

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

34

norwalk virus occurs when??

associated with ??

summer

shellfish, other food, water is a common vehicle


35

Norwalk virus occurs in what groups?

community-wide outbreaks, families
nursing homes

36

norwalk virus presentation
duration?

acute vomiting, diarrhea, *fever*, *myalgia and ha*
1-2 days

37

enteric adenovirus
causes what in who ??
seasonality??

dsDNA
enteric diarrhea of infants and young children
no seasonality here

38

enteric adenovirus presentation
duration

prolonged diarrhea
*5-12 days*
vomiting and fever

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