Viruses Of The Gastointestinal Tract

Question 1

What are symptoms of acute viral gastroenteritis?

Answer 1

Diarrhoea
Vomiting
Abdominal discomfort
Fever
Rotavirus, norovirus, enteric adenovirus, astrovirus, calcivirus

Question 2

What is epidemic gastroenteritis caused by?

Answer 2

Norovirus

Question 3

What is sporadic gastroenteritis in very young people caused by?

Answer 3

Rotavirus

Question 4

What is sporadic acute gastroenteritis caused by?

Answer 4

Calicivirus
Rotavirus
Astrovirus
Adenovirus

Question 5

What is the difference in immunity for norovirus?

Answer 5

Immunity is shortlived and occurrence is outbreak, so can kee getting the same strain

Question 6

How do people transmit GI viruses?

Answer 6

Can be transferred to food via ill worker or ingested orally by new host from food or water which contains virus

Question 7

What are the biggest cause of norovirus?

Answer 7

Shellfish

Question 8

What is rotavirus morphology?

Answer 8

A genus within the family reoviridae, resembles a wheel hence rota
Non enveloped

Question 9

What is the rota virus genome?

Answer 9

dsRNA segmented
Structural viral proteins
Outer capsids
Core proteins
Non structural proteins

Question 10

What is rotavirus classification?

Answer 10

Group A - significant diarrhoea illness in the young, more important , vaccines are made to sterotypes within this group
Group B - annual epidemics in adults especially in china
Group C - sporadic child cases, also in outbreaks
Group D, E and F - in animals, thus far

Question 11

What are the four most common strains of rotavirus?

Answer 11

P8G1, P8G3, P8G4, P4G2

Question 12

How are strains named of rotavirus

Answer 12

VP4 antigen: P (protease-cleaved protein)
Serotype; 8 human viruses
Therefore p8G1

Question 13

What is pathogenesis of rotavirus?

Answer 13

Infect upper two third of duodenal epithelial cell
Infectious particles are released to intestinal lumen and undergo further replication in distal areas

Question 14

What happens to microvilli in rotavirus?

Answer 14

End up with problems with microvilli becoming shortened , they can’t absorb nutrients like normal

Question 15

What happens to epithelia in rotavirus?

Answer 15

Increased paracellular permeability by weakening tight junctions between cells

Question 16

What is diagnosis and treatment for rotavirus?

Answer 16

Antigen enzyme immunoassay (EIA) of stool specimens
RT-PCR
Non-specific treatment: oral rehydration therapy to prevent dehydration
Intravenous fluid is required in several infant cases
Immunisation by vaccines

Question 17

What is the rotashield vaccine?

Answer 17

Three viruses contain 10 genes from simian strain RRV and gene segment 9 (vp7) from human strains G1, G2, or G4
The fourth virus is simian strain RRV (whose vp7 is similar to human G3)

Question 18

What was the risk of rotashield?

Answer 18

Intussusception, this is inversion of the intestines with one another , was taken off the market despite it being a good vaccine

Question 19

What is rotarix?

Answer 19

Derived from one strain - P8G1
Relies on cross reactivity - not so effective on P4G2 strains

Question 20

What is rotateq?

Answer 20

Derived from bovine-human recombinant by reassormtnet
Grows less well int he human gut requires multiple doses
But has P8 G1-G4

Question 21

What is hyperemesis hiemis?

Answer 21

Winter vomiting disease