Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiology > viral gastroentitis > Flashcards

viral gastroentitis Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Which fmaily is rota virus in

A

Reoviridae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

epidemiology of rotaviruses

A

o Rotaviruses are major cause of
diarrheal illness in children (3-5years) /neonates
o peak age = 4 - 23 months
o Adults too can get infected.
o Young animals also infected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

which animal host does rotavirus have

A

Young animals,calves,piglets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what factor plays a role in rotavirus infection

A

poor hygiene - esp in underdeveloped countries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

structure of rotavirus

A
  • non-enveloped
  • icosahedral
  • triple shelled
  • genome = 11 segments of dsRNA ( has genetic reassortment)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how many structural & nonstructural proteins does RNA of rotaviruse encode for?

A

structural = 6
non-structural = 5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how is rotavirus transmitted

A
  • fecal-oral route (water/food)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

is rotavirus highly infectious and how can tell?

A
  • High numbers of viral particles
    are shed in diarrheal stools
    (1010/gm) - highly infectious
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

whats the incubation period of rotavirus

A

1-3 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

clinical symptoms of rotavirus

A
  • for some adults may aymptomatic
  • for young children & some other adults after IP = leading to :
    - watery Diarrhea
    - abdominal pain
    - Vomiting
    - Dehydration
    - Shock
    - Death
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how many days does it take for people with milder rotavirus infection recover

A

3-8 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

which cells does rotavirus infect

A

enterocytes - aid in digestion & absorb nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what happens when those enterocyte cells infected

A

it causes diarrhoea & less absorption of nutrients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

pathogenesis of rotavirus

A

oThe virus infect villi of SI : destroys the mature enterocytes in the villus epithelium
o They multiply in the enterocytes and damage their transport mechanisms
o The RV particle NSP4 is a viral enterotoxin & induces secretion by triggering a calcium - dependent signal transduction pathway
o Damaged cell may slough into lumen of the intestinal and release large quantities of virus which appear in the stool.
o Viral excretion usually lasts for 2–12days in healthy patients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why Diarrhea in Rota-viral Infections

A

1.secretory diarrhea by reducing villous epithelium + increasing secretory crypt cells
(impared Na & glucose absorption as damaged cell on villi are replaced by non absorbing immarture crypt cell )
2.osmotic diarrhea = by reducing brush border enzymes causing accumulation of unmetabolized disaccharides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how to detect infants are suffering from rotavirus

A
  • child is vomiting and diarrhoeing
  • eye sunkened
  • child crying w no tears
  • sunken fontanelle
  • dry mouth /tongue
  • decreased skin tugor - (normally - more tight - but is now loose)
  • sunken abdomen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

immunity of rotavirus

A

o By age 3years , 90% of the children have
serum antibodies to one or more types.

o Young children suffer up to five reinfections
by 2years ofage.

o Secretary IgA or Interferon are important in protection against Rota viral infections.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how is rotavirus diagnosed in lab

A

can be detected in the stool via
o ELISA
o Latex agglutination - looking for antigen to rotavirus
o PCR

human rotavirus does not grow readily in cell culture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

treatment of rotavirus

A

o Treatment of Gastroenteritis is supportive.

o Correction of Loss of water and electrolytes
- Failure for prompt correction of
dehydration lead to Acidosis Shock Death.

o Correction Electrolyte remain the goal treatment in Rota viral infections.

o replacement of fluid & restoration of electrolyte balance

20
Q

prevention & control

A
  • waste water management, safe water
    supplies     and sanitation ,education
  • Vaccine – In 2006 an Oral Bovine based
    Rotaviral vaccine was licensed inUSA.
21
Q

differentiate between Endemic & epidemic viral gastroenteritis

A

Endemic = cause of GE among infants & young children
Epidemic(outbreak) - cause of GE in all ages

22
Q

which type of adenovirus cause gastroenteritis

A

Adenovirus 40 & 41

23
Q

strucutre of adenoviruse 40&41

A

naked
DNA virus

24
Q

edidemiology

A

usually causes GE in young children & neonated

25
Q

which subfamily is rota-virus in

A

sedoreovirinae ( appears more smooth - lacking large surface glycoproteins)

26
Q

how many species are there of rotaviruses & which ones infect humans

A

A-H
infect humans = A,B,C

27
Q

Classify group b & C of Rotavirus

A

Group B - causes adult diarrhoea
Group C - causes pediatric gastroenteritis

28
Q

how many serotypes are identified in group A of rotavirus & which are common?

A

10 G
But 5 types common (G1-G4 & G9)

29
Q

what are some examples of rotaviruses known to cause specific types of diarrhea in various species

A
  • human infantile diaarhea
  • nebraska claf diarrhea
  • epizootic diarrhea of infant mice
  • SA11 virus of monkety
30
Q

which structural protein can be used for immunoassay & grouping rotaviruses

A

VP-6 major structurla protein - (target for commercial immunoassay & determines group specificity of rotaviruses)

31
Q

role of the VP4 & VP7 structual proteins of rotavirus

A

VP4 & VP7 = carry epitopes for neutralizing activity
VP7 = predominant antigen

32
Q

what are the main causes of secretory diarrhea by rotavirus

A
  1. reducing villous epithelium & incresaing crypt cells
  2. enterotoin (NSP4) - which alters epithelial cell function & permeability
    3.Activation of enteric nervous system in intestinal wall
33
Q

What family & genera is norwalk viruses in

A

Family: calicivirdae
Genus : norovirus

34
Q

the norwalk virus can be cultured true/false

A

false

35
Q

Antigen property of norovirus

A
  • undergoes antigenic drift over time - in reposnse to population immunity
36
Q

What is the recepetor for norwalk-like viruses

A

histocompatibility blood group antigens expressed on the mucosal epithelia of digestive tract

37
Q

calciviruses

A
  • Small RNA viruses, characteristic surface morphology
    consisting of hollows. particles 35 nm in diameter.
  • Associated mainly with epidemic outbreaks of
    gastroenteritis, although occasionally responsible for
    endemic cases.
  • Like Norwalk type viruses, vomiting is the prominent
    feature of disease.
  • Majority of children have antibodies against caliciviruses
    by the age of three.
  • Diagnosed by electron microscopy only, often difficult
    to diagnose because of small size.
38
Q

incubation period of norwalk viral gastroenteritis

A

24-48hrs

39
Q

epidemiology of norwalk viruses

A
  • causes mild gE in community and affect all age groups
  • are major causes of epidemic of GE
  • survives 10ppm chlorine & heating of 60 degress - can maintain viabikity in steamed oysters
40
Q

clinical presentation of norwalk virus

A

onset is rapid & clinical course is brief (12-60hrs)
symptoms
- diarrhea - MC in adults
- nausea
- vomiting - MC in children
- lowgrade fevr
- abdominal cramps
- headache
- malaise

41
Q

Pathogenesis of norwalk viruses

A

1.attached on carbo of duodenal epithelium of individula w secretor phenotype
2.reversible lesion in upper jejunum e.g broadening & blunting of villi , shortening of microvilli
3.malabsorption of carbohydrates & fats & decreased brush border enzyme
4.Gastric motor function is delayed

42
Q

diagnosis of norwalk viruses

A

1.PCR - detection of virus in stool & vomitus
2.EIA (Enzyme immunoassay) - detection of virus in stool & 3.serologic responce to specific viral antigen

43
Q

how are norwalk viruses spread

A

aerosolization , contact w contaminated fomites , person to person contact

44
Q

immunity to norwalk viruses

A

antibody is acquried later in life than the roatavirus

45
Q

treatment & control

A
  • effective handwashing
  • care taken in disposal of stoll
    -containment & disinfection of soiled areas & bedding
  • careful procesisng of food & educate food handles
  • purification of drinking water , swimming pool

NO VACCINE

Microbiology (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions