Viral Gastroenteritis Flashcards
The family Reoviridae is divided into ___ genera.
_____ of the genera are able to infect humans and animals:
15
Four
The family Reoviridae
Four of the genera are able to infect humans and animals:
______
_______
________
___________
Rotavirus
Orthoreovirus
Coltivirus
Orbivirus
The family Reoviridae
Four of the genera are able to infect humans and animals:
Rotavirus – ___ segments
Orthoreovirus – ___ segments
Coltivirus – ___ segments
Orbivirus – ___ segments
11
10
12
10
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
The family Reoviridae
The individual RNA segments vary in size from _____ (_____virus) to ____ bp (____virus).
680
rota
3900
orthoreo
The virion core of reoviridae contains several enzymes needed for transcription and capping of viral RNAs
T/F
T
___________ is the second most common viral illness after upper respiratory tract infection.
Viral gastroenteritis
Viral gastroenteritis
It mainly affects ___________ ————
Children under 5 years
Viruses are responsible for up to _____ of all infective diarrhoeas.
3/4
In developing countries, viral gastroenteritis is a major killer of _____ who are ___________.
infants; undernourished
Rotaviruses are responsible for __________ deaths a year.
half a million
Many different types of viruses are found in the gut and all are associated with gastroenteritis.
T/F
F
Many different types of viruses are found in the gut but only some are associated with gastroenteritis.
Causes of viral gastroenteritis
_____virus
_________ ______virus
_______virus
______virus
Rota
Enteric adeno
Calici
Astro
ROTAVIRUS
(Enveloped or Non enveloped?)
__________ shape
_______ nm in diameter with a characteristic _____-shaped structure (rota)
family ____viridae.
Non enveloped
icosahedral
60 -80
wheel; Reo
ROTAVIRUS
______ shells: ________________________________
three
an outer capsid, an inner capsid and a core.
ROTAVIRUS
______ segments of ______-stranded RNA,
____ structural proteins
____ non-structural proteins
11; double
6
5
ROTAVIRUS
6 structural proteins (_____,____ ,______)
5 non-structural proteins (______-_______).
VP1–VP4, VP6, VP7
NSP1–NSP5
ROTAVIRUS
VP4 and VP7
encode protein of the _________
are targets for __________
Targets for ________
Used to classify ______
outer capsid
neutralising antibodies.
vaccine production
serotypes
Rotavirus
VP6 – used to classify ________
serogroups
ROTAVIRUS
__________________ occurs readily
Genetic reassortment
ROTAVIRUS
___ serogroups (_________) are associated with human disease.
3
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
49
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
T
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
