Viral GI Infections Flashcards
List the 5 main viruses causing GI infection.
Which ones occur in healthy people?
Which ones occur in the young/elderly/immunocompromised?
AFFECTING HEALTHY PEOPLE:
Norovirus
Sapovirus
AFFECTING THE YOUNG/ELDERLY/IMMUNOCOMPROMISED:
Rotavirus
Adenovirus 40 and 41
Astrovirus
List 4 viruses which replicate in the gut but do NOT cause GI disease.
Poliovirus
Other enteroviruses
Adenoviruses
Hepatitis A
What type of virus is sapovirus?
Calicivirus
What type of virus is norovirus?
Describe its structure. (3)
Non-enveloped
ssRNA
Antigenic variation
Describe the 6 types of norovirus.
Which ones affect humans? (3)
Groups 1-6
AFFECTING HUMANS:
- Group 1
- Group 2
- Group 4
How do you diagnose norovirus infection? (2)
PCR
-Testing for viral DNA
Bristol stool chart
-Types 6 or 7
Describe the Bristol stool chart. (7)
Type 1 - separate hard lumps
Type 2 - lumpy and sausage like
Type 3 - sausage shape with cracks in the surface
Type 4 - smooth, soft sausage or snake
Type 5 - soft blobs with clear cut edges
Type 6 - mushy consistency with ragged edges
Type 7 - liquid
Describe the epidemiology of norovirus. Consider:
a) Transmission (3)
b) Infectious dose
c) Infectious period
d) Outbreaks
TRANSMISSION:
Person-person
Contaminated food
Contaminated water
INFECTIOUS DOSE:
10-100 (very low)
INFECTIOUS PERIOD:
From: Onset of symptoms
To: 48 hours after symptoms stop
OUTBREAKS:
Common
Describe the clinical features of a norovirus infection. (7)
Asymptomatic Vomiting/nausea Diarrhoea Abdominal pain Headache Muscle aches Fever (rare)
Describe 2 complications of norovirus infection.
In which patient groups do these occur?
Dehydration
- Young patients
- Elderly patients
Chronic diarrhoea and virus shedding
- Solid organ transplants
- Bone marrow transplants
Describe treatment of norovirus infection. (4)
Symptomatic therapy:
- Oral/IV fluid replacement
- Antispasmodics
- Analgesics
- Antipyretics
Describe infection control measures needed for norovirus infection. (6)
Isolation/cohorting Exclusion of symptomatic staff Do not admit new patients Thorough cleaning of environment 48 hours after last case Patient/visitor awareness Hand hygiene
What type of virus is rotavirus?
Describe its structure. (2)
Reovirus
dsRNA
Segmented (11 strands)
Describe the epidemiology of rotavirus. Consider:
a) At risk populations (3)
b) Infectious dose
c) Infectious period
d) Outbreaks
AT RISK POPULATIONS:
Children under 2 yo
Elderly
Immunocompromised patients
INFECTIOUS DOSE:
10-100 (very low)
INFECTIOUS PERIOD:
While symptoms are present
OUTBREAKS:
Frequent in paediatric wards
What is the incubation period for rotavirus?
How long does a rotavirus infection normally last?
Incubation period: 2 days
Duration: 3-8 days
Describe the symptoms of rotavirus infection. (5)
Anorexia Low grade fever Watery diarrhoea Vomiting Abdominal pain
Describe the treatment for rotavirus infection. (1)
Rehydration therapy
Can you get immunity to rotavirus?
How?
Yes
Rotavirus vaccine (Rotarix)
Is the rotavirus vaccine live or not?
Live
Describe the infection control measures needed for rotavirus. (4)
Isolation/cohorting
Do not admit any new patients
Thorough cleaning of the ward
Patient/visitor awareness
How do you diagnose adenovirus? (3)
PCR (viral DNA)
Bristol stool chart:
-Types 6 or 7
ELISA test (viral antigens)
Can you get immunity to norovirus?
How?
Yes - but only lasts <1 year
Previous infection
