Lecture 17: Viral Enteric Pathogens

Question 1

List enteric pathogens (bacteria)

Answer 1

Salmonella spp.
Shigella spp.
E. coli (specific types)
Campylobacter spp
Yersinia spp.
Clostridium difficile

Question 2

List enteric pathogens (viruses)

Answer 2

Rotavirus
Norovirus
Astrovirus
Adenovirus
Enterovirus

Question 3

List parasitic enteric pathogens

Answer 3

Entamoeba
histolytica
Giardia lamblia
Cryptosporidium

Question 4

Viral gastroenteritis is when a patient has

Answer 4

Syndrome of acute nausea and vomiting, typical in winter months and lasts for 1-3 days

Question 5

What are the two possible syndromes of viral gastroenteritis?

Answer 5

Mild afebrile disease with watery diarrhea, or more severe with vomtitng, headache etc..

Question 6

Astrovirus

Answer 6

Especially amongst the paediatric
population

Question 7

Adenovirus

Answer 7

-Enteric
-Alot of pets inpatient diarrhea

Question 8

What are caliciviruses?

Answer 8

Those that are not noro

Question 9

List a few likely and emerging pathogens

Answer 9

• Caronaviruses
• Enteroviruses
• Especially echovirus types 11, 14 and
  18
• Torovirues
• Picrobirnaviruses, Picotrimaviruses.
• Pestiviruses.

Question 10

What type of virus is a norovirus?

Answer 10

Non-enveloped, isochahedral virus
SS positive sense RNA Genome

Question 11

Which virus looks like a cupcake?

Answer 11

Noro ,a member of the calicivirdae family

Question 12

How is noro transmitted?

Answer 12

Vomitus and airborne transmission
100 particles needed for transmission

Question 13

Incubation period for norovirus?

Answer 13

18-72h, virus shedding happens in stool

Question 14

How long can virus particles get picked up on after a noro infection with PCR?

Answer 14

3 weeks after illness

Question 15

What happens with most noro outbreaks?

Answer 15

They terminate spontanoeously

Question 16

How do you treat Noro?

Answer 16

Isotonic liquids, symptomatic treatment, NO antibiotics

Question 17

How long are you on contact precautions with noro?

Answer 17

Until symptoms resolve, hand washing, ID and elimination of common surfaces

Question 18

Describe the characteristics associated with the Rotavirus

Answer 18

Only double-stranded RNA genome, non-enveloped virus

Question 19

What is characterized by “empty” particles with dark centres which lack genomic RNA

Answer 19

Rotavirus

Question 20

Group A,B,C rotavirus

Answer 20

Human and non-human diseases

Question 21

Group A Rota

Answer 21

Most important clinically; causes endemic GE in kids

Question 22

Group B and C

Answer 22

Epidemic GE affecting all ages

Question 23

Group D to G Rotavirus

Answer 23

Non-human disease

Question 24

How is rotavirus transmitted?

Answer 24

Fecal-oral transmission ; detected by 4-10 days in 57 days PCR

Question 25

What are some possible pathogenesis of rotavirus ?

Answer 25

a) Malabsorption of related mucosal damages and depression of disaccharides b) Shortened and blunted villi in duodenum, with crypt hypertrophy, and mononuclear infiltration

Question 26

What reflexes are activated in the enteric nervous system and what do they cause?

Answer 26

Secretary reflexes, fluid secretions

Question 27

Signs and symptoms of rotavirus?

Answer 27

Vomiting and Fever, profuse diarrhea, more severe symptoms with dehydration than other pathogens

Question 28

Why is there death is rotavirus?

Answer 28

Death due to dehydration and severe electrolyte abnormalities leading to cardiac arrest

Question 29

Treatment of Rotavirus

Answer 29

Rehydration, electrolytes, oral rehydration solutions are preferred, IV, NOT antibiotics

Question 30

Why is it hard to control rotavirus infections?

Answer 30

Physically hardy, non-enveloped

Question 31

Rotavirus is a vaccine in Ontario (T/F)

Answer 31

TRUE

Question 32

Disease burden of rotavirus peaks in...

Answer 32

Winter-spring, but this declined since the publicly funded vaccine program introduction in 2011

Question 33

How do you propagate an enteric virus in vitro?

Answer 33

you DONT

Question 34

How do you diagnose rotavirus in a lab?

Answer 34

Take advantage of high viral loads in stool and use electron microscopy to diagnose, or PCR, or antigen detection