Viral GI infection Flashcards
Who is at higher risk of viral gastroenteritis?
- children under age 5
- Old people, especially those in nursing homes
- Immunocompromised
Name 5 viruses that cause gastroenteritis
- Adenovirus (40 and 41)
- Norovirus
- Sapovirus
- Rotavirus
- Astrovirus
Which groups are affected most by norovirus/sapovirus?
Can affect all ages and healthy individuals but often most serious in the young and elderly
Which groups are affected by rotavirus/adenovirus/astrovirus?
Mainly children under 2, elderly and immunocompromised
What family is norovirus?
Calciviridae
Describe the structure of norovirus
Non enveloped, single stranded RNA
Which strain of norovirus is most common in the UK?
GII-4
What is the transmission of norovirus?
- Person to person (faecal-oral, aerosolised e.g. by toilet flush. fomites)
- Food bourne
- Water
What is the infectious dose of norovirus?
10-1000 virions
What is the incubation period of norovirus?
24-48 hours
How long can the virus be shed after infection?
3 weeks
What are the clinical features of norovirus?
- Can be asymptomatic
- Vomiting
- Diarrhoea
- Nausea
- Abdominal cramps
- Headache
- Muscle aches
- Fever in the minority
- Dehydration in young a elderly
What is the duration of norovirus infection?
12-60 hours
What are the complications of norovirus?
- Siginifcant proportion of childhood hospitalisation
- Illness in hospital outbreaks last longer with an increased risk of mortality (underlying illness)
- In elderly increased post infection complications
- Chronic diarrhoea and virus shedding in both solid organ transplant patients and bone marrow transplant patients (shedding for up to 2 years)
What is the treatment of norovirus?
- Oral and/or IV therapy
- Antispasmodics
- Analgesics
- Antipyretics (if fever)
How long does immunity to norovirus last?
6-14 weeks
What are the infection control measures for norovirus?
•Isolation or cohorting
•Exclude symptomatic staff until symptom free for 48 hours
•Do not move patients
•Do not admit new patients
•Thorough cleaning of ward/hotel/cruise ship/ bus
- 48 hours after the last symptomatic case
- dilute hypochlorite or hot soapy water
•Patient/visitor/passenger/guest awareness
What is the structure of rotavirus?
- Double stranded, non enveloped RNA virus
* 11 strands of RNA
Describe the transmission of rotavirus
- Low infectious dose (10-100 virus particles)
- Mainly person to person via face-oral or fomites
- Food and water borne spread is possible
- Spread via respiratory droplets is speculated
What is the incubation period of rotavirus?
1-3 dyas
What are the symptoms of rotavirus?
- Watery diarrhoea
- Abdominal pain
- Vomiting
- Loss of electrolytes leading to dehydration
how long do symptoms of rotavirus last?
3-7 dyas
when is the most severe infection likely to occur with rotavirus?
1st infection after age 3 months
What are the complications of rotavirus?
- Severe chronic diarrhoea
- Dehydration
- Electrolyte imbalance
- Metabolic acidosis
- Immunodeficient children may have more severe or persistent disease
