Viral Gastroenteritis Flashcards by Iseoluwa Ojo

The family Reoviridae is divided into ___ genera.

_____ of the genera are able to infect humans and animals:

Four

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The family Reoviridae

Four of the genera are able to infect humans and animals:

______
_______
________
___________

Rotavirus
Orthoreovirus
Coltivirus
Orbivirus

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The family Reoviridae

Four of the genera are able to infect humans and animals:
Rotavirus – ___ segments
Orthoreovirus – ___ segments
Coltivirus – ___ segments
Orbivirus – ___ segments

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The family Reoviridae

Genome consists of

______-stranded (DNA or RNA?) in ______ discrete segments

Total genome size of ____ kbp, depending on the genus.

double

RNA; 10–12

16–27

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The family Reoviridae

The individual RNA segments vary in size from _____ (_____virus) to ____ bp (____virus).

680

rota

3900

orthoreo

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The virion core of reoviridae contains several enzymes needed for transcription and capping of viral RNAs

T/F

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___________ is the second most common viral illness after upper respiratory tract infection.

Viral gastroenteritis

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Viral gastroenteritis

It mainly affects ___________ ————

Children under 5 years

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Viruses are responsible for up to _____ of all infective diarrhoeas.

3/4

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In developing countries, viral gastroenteritis is a major killer of _____ who are ___________.

infants; undernourished

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Rotaviruses are responsible for __________ deaths a year.

half a million

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Many different types of viruses are found in the gut and all are associated with gastroenteritis.

T/F

Many different types of viruses are found in the gut but only some are associated with gastroenteritis.

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Causes of viral gastroenteritis

_____virus
_________ ______virus
_______virus
______virus

Rota

Enteric adeno

Calici

Astro

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ROTAVIRUS

(Enveloped or Non enveloped?)

__________ shape

_______ nm in diameter with a characteristic _____-shaped structure (rota)

family ____viridae.

Non enveloped

icosahedral

60 -80

wheel; Reo

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ROTAVIRUS

______ shells: ________________________________

three

an outer capsid, an inner capsid and a core.

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ROTAVIRUS

______ segments of ______-stranded RNA,

____ structural proteins

____ non-structural proteins

11; double

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ROTAVIRUS

6 structural proteins (_____,____ ,______)

5 non-structural proteins (______-_______).

VP1–VP4, VP6, VP7

NSP1–NSP5

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ROTAVIRUS

VP4 and VP7

encode protein of the _________

are targets for __________

Targets for ________

Used to classify ______

outer capsid

neutralising antibodies.

vaccine production

serotypes

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Rotavirus

VP6 – used to classify ________

serogroups

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ROTAVIRUS

__________________ occurs readily

Genetic reassortment

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ROTAVIRUS

___ serogroups (_________) are associated with human disease.

A, B C

Enteric adenovirus

(Enveloped or Non enveloped?)

_________ shape

________nm

Non enveloped

Icosahedral

70 – 90

Enteric adenovirus

Linear or circular?)

______ stranded (DNA or RNA?)

Replication – ________

Linear

Double; DNA

nucleus

Enteric adenovirus

Human adenoviruses are divided into ____ groups (_______) with about ____ antigenic types.
Group F is associated with gastroenteritis
•
Types 40 and 41 cause infantile gastroenteritis

6; A – F

Enteric adenovirus Group ____ is associated with gastroenteritis Types _____ and _____ cause infantile gastroenteritis

F 40 and 41

Caliciviruses (Enveloped or Non enveloped?) (Spherical or icosahedral?) ________nm

Non enveloped icosahedral 27 – 40

Caliciviruses (Linear or circular?) , _______ sense _____ stranded (DNA or RNA?) Replication – _______

Linear ; positive single; RNA cytoplasm

Caliciviruses Norovirus – ________ 3 genotypes – ___,___,____

Norwalk GI, GII, GIV

Caliciviruses _________virus the most important cause of epidemic viral gastroenteritis in adults

Sapporo

Astroviruses _______ sense _______ stranded (DNA or RNA?) virus _______ pointed _____ on their surface

Positive; single RNA 5 – 6; stars

Astroviruses (Enveloped or Non enveloped?) (icosahedral or spherical?) ________nm in diameter

Non enveloped icosahedral 28 – 30

Astroviruses _____ serotypes ______-_____ kb in size

8 6.8 – 7.9

Astroviruses Replication – _________

cytoplasm

Rotaviruses are the single most important worldwide cause of gastroenteritis in ____________

young children

By _______, 90% of children have serum antibodies to rotavirus

3 years

In temperate climates, rotavirus occurs mainly in (summer or winter?) .

Winter

Norwalk virus is associated with epidemics and more common in (adults or children?) than (adults or children?) .

adults Children

Adenoviruses cause (adults or infantile?) gastroenteritis

infantile

Rotavirus account for 20–70% of _______ of ______ 20% of all _______ in children under 5 years of age

hospitalized cases ; diarrhoea diarrhoeal deaths

Rotavirus Asymptomatic clinical infection are common in _____ less than ________ due to _____________________

infants; 6 months maternal antibodies

Calicivirus – ______ rise slowly reaching a peak of about ____% in the _____ decade

Antibodies 50 fifth

_____virus – Causes outbreaks of gastroenteritis in schools, camps and cruise ships.

Calici

Pathogenesis Transmission is by the __________ route Person to person through ____________ Eating _________ fruits and vegetables contaminated with _______________

faeco-oral contaminated hands. uncooked; infectious fecal material.

Pathogenesis Drinking water contaminated with ____________________ Contamination of uncooked food, fruits and salads by __________________.

infectious fecal material. food handlers

Pathogenesis Rotaviruses appear to localize primarily in the _________ and _________ causing __________ of __________ with ___________ Damage the _____________ of enterocytes

duodenum and proximal jejunum destruction of villous epithelial cells with blunting of villi transport mechanism

Pathogenesis Rotaviruses Damage the transport mechanism of enterocytes _______ is an enterotoxin which induces ________ As a result, _____________ of __________ occurs .

NSP4 ; secretion maladsorption of fluids and electrolytes

Pathogenesis Rotaviruses are shed in the stool T/F

Incubation period – Rotavirus:________ Norwalk virus: ___________ Adenovirus: _________

1 – 3 days 10 -51 hours 8 – 10 days

Clinical features of viral gastroenteritis Vomiting (persist for ___________) Copious ____________ ( persists for _______ days) (Low or High?) grade fever may be present __________

1 – 3 days watery diarrhoea ; 4 – 8 Low Dehydration

Diagnosis Antigen detection using ELISA •–_________,________ Electron microscopy –______,________,_________,________ Polymerase chain reaction – ________,_______,______,_________

Rotavirus, Adenovirus Rotavirus, Adenovirus, Norwalk virus, Astrovirus Rotavirus, Adenovirus, Norwalk virus, Astrovirus

Treatment of viral gastroenteritis _______ antiviral therapy _________ therapy Replacement of fluids and electrolytes –______ – Oral ___________

No Supportive IV fluid rehydration salt

Prevention Vaccination _______,______ Given at _________,________, and ________ access to safe drinking-water; use of improved sanitation; hand washing with soap; good personal and food hygiene; health education about how infections spread

Rotarix, RotaTeq 2 months, 4 months and 6 months