Norovirus

Question 1

What is the most common cause of gastroenteritis in England and Wales?

Answer 1

Norovirus

Question 2

Norovirus contains double-stranded RNA. True or false?

Answer 2

False - ssRNA

Question 3

Norovirus is a non-enveloped virion. True or false?

Answer 3

True

Question 4

Does norovirus have a high or low infectious dose and what does this mean?

Answer 4

Low infectious dose - don’t need to acquire a lot of the virus for an infection to be caused

Question 5

Norovirus has only one variant. True or false?

Answer 5

False - it is variable

Question 6

Is there a vaccine that protects against norovirus?

Answer 6

No

Question 7

What are the symptoms of norovirus?

Answer 7

Often start with sudden onset of nausea followed by projectile vomiting and watery diarrhoea
headaches
myalgias and malaise
low-grade fever
abdominal cramps
gastroenteritis develops 24-48h after consumption of contaminated food/water/contact with infected individual
episodes are short-lived often lasting 24-72h

Question 8

How is norovirus transmitted?

Answer 8

Person-person
aerosol exposure (droplets)
faecal-oral route

Question 9

Norovirus is highly contagious. True or false?

Answer 9

True - infection requires fewer than 10 virions

Question 10

Norovirus is extremely stable in the environment. True or false?

Answer 10

True

Question 11

Viral shedding may occur for up to how many weeks after infection?

Answer 11

3

Question 12

Can recurrent infection of norovirus happen?

Answer 12

Yes because of the diversity of strains and lack of long-term immunity

Question 13

Why can infection with norovirus lead to lactose intolerance?

Answer 13

Because virus infects the brush border of the small intestine, the machinery that absorbs lactose is damaged

Question 14

The most effective prevention of norovirus is through hand washing. True or false?

Answer 14

True

Question 15

Infection damages microvilli of intestine. True or false?

Answer 15

True

Question 16

People infected with norovirus should keep themselves isolated for 48 hours. True or false?

Answer 16

True

Question 17

Closure of hospital wards usually takes place when there is an outbreak. True or false?

Answer 17

True

Question 18

There is a specific medication for treatment of norovirus. True or false?

Answer 18

False

Question 19

What are the “danger symptoms” of norovirus?

Answer 19

Blood in stools
Mucus in diarrhoea
Symptoms of severe dehydration - weakness, confusion, rapid HR

Question 20

Oral rehydration is important. True or false?

Answer 20

True

Question 21

Loperamide can be given for acute diarrhoea. What is the mode of action?

Answer 21

Binds to opiate receptor in gut wall - reduces propulsive peristalsis and increasing intestinal transit time

Question 22

Rotavirus and norovirus are the same thing. True or false?

Answer 22

False

Question 23

Rotavirus is the most common cause of gastroenteritis in children. True or false?

Answer 23

True

Question 24

Norovirus is the most common cause of gastroenteritis in adults. True or false?

Answer 24

True

Question 25

What are the referral criteria for norovirus?

Answer 25

Any “dangerous symptoms”
pregnancy
>1 day symptom duration in children <1 year
>2 day symptom duration in children <3 years and elderly
>3 day symptom duration in older children and adults
diarrhoea associated with severe vomiting and fever