Astro/noro/rota/sapo Flashcards
Mum is on rituximab and receives a dose during pregnancy. Which vaccine(s) can’t the baby have?
“immunisation with live vaccines should be delayed until 6 months of age in children born to mothers who received immunosuppressive biological therapy during pregnancy. In practice, this means that children born to mothers who were on immunosuppressive biological therapy during pregnancy will not be eligible to receive rotavirus vaccine (and will need to defer BCG, if indicated, for 6 months). “
From chapter 6 green book
Which species of rota virus most commonly causes human infection?
Rotavirus A species based on VP6 protein. Further subclassified by G and P type using VP7 and VP4 respectively
Rotavirus vaccine -
type?
Recipients and schedule?
Contraindications?
Live attenuated oral vaccine
Given as 2 doses
-First dose at 8 weeks and not later than 15 weeks
- Second dose at 12 weeks and not later than 24 weeks
Dosing schedule designed to minimise possible risk of intussusception
Contraindications
- Mother received biological immunosuppression during pregnancy. (live vaccine CI for first 6 months)
- SCID
- child with hx intussusception
What timings can the the rota virus be given/not given?
First dose
- After 8 weeks and no later than 15
- Second dose 4 weeks after first and no later than 24.
Appearance of astrovirus on EM ?
28-30nm (small)
5 or 6 pointer star appearance.
- Not all virions (usually around 10% and pH dependent)
Genome of rota virus and EM appearance?
Looks like a wheel - rota = latin for wheel.
Genome - ds RNA gapped genome.
** the genome can rotate (antgenic shift) more than others**
Most common strain of norovirus in uk?
GII.17
Strain of norovirus associated with worse disease?
GII.4
Gene which confers resistance to norovirus infection?
Fut2 - occurs in around 20% of European descendants. Homozygotes don’t display h proteins in their gut which is required for some noro strains to infect (esp gii.4). H protein part of ABOH blood grouping proteins.
If you’ve got 2 feet (fut) you can outrun noro
Incubation and infectious period for noro
Incubation - short 12-48h
Infectious period - Symptom onset until 48h afterwards
Vaccine trials in uk for noro?
Type of vaccine and coverage?
mRNA-1403 – Moderna sponsored phase 2 trial underway in the UK. Trivalent mRNA-based candidate containing mRNAs that encode for the major capsid protein 1 (VP1) of three globally prevalent Norovirus genotypes—GII.4, GI.3, and GII.3.
HilleVax - VLP vaccine with phase 2 trials underway - contains antigens to GI.1 and GII.4 genotypes
What are the families of:
Norovirus
Rotavirus
Sapovirus
Astrovirus
Caliciviridae
Reoviridae
Caliciviridae
Astroviridae
What type of virus (+/- ss/ds) are:
Norovirus
Rotavirus
Sapovirus
Astrovirus
+ssRNA
dsRNA
+ssRNA
+ssRNA
Incubation periods of:
Norovirus
Rotavirus
Sapovirus
Astrovirus
12-48 h
1-2 d
1-4 d
1-4 d
What are the extra-GI manifestations of Astrovirus?
Encephalitis and meningitis (mostly) in immunosuppressed
How many genogroups of norovirus are there?
Which most cause human infect humans?
How are genotypes subdivided?
10
GI and GII
Based on G and P types (same as rota)
How long does norovirus shed in stool post infection?
Weeks in immunocompetent, even longer (up to years) in immunocompromised
Does asymptomatic infection pose a transmission risk in norovirus?
Yes, asymptomatic infection still results in high stool viral shedding
Which groups are most at risk of severe norovirus infection?
Infants
Immunosuppressed
Elderly
What are the extra-GI manifestations of norovirus?
Seizures in young children
Encephalopathy
Acute liver disease
What patients are at risk of chronic norovirus?
What are the symptoms?
What treatment have been used in chronic noro?
Immunocompromised
Malabsorption and wasting
Reduction of immunosuppression
Dietary interventions
Nitazoxanide
Ribavirin
Prednisolone
Favipirivir
What defines the end of a norovirus outbreak?
72 h after the last episode of vomiting or diarrhoea
What PPE should be worn when working with a patient with norovirus?
What additional PPE is required if there is a risk of splashes?
Gloves and aprons
Type IIR fluid resistance surgical mask and eye protection
