Virology questions Flashcards
Systemic PCR run, 2 positive results
86 year old - ?shingles - HSV pos
36 year old - ?PROM - VZV pos
what action would you take?
Gather information
Results could be correct e.g if 86 year old has recurrent herpes, and 36 year old has chickenpox rash
However, more likely samples are swapped
Need to go back to original samples, and repeat testing
Will take 24 hours, so recommend treating both until results known
48 year old, post liver transplant
CMV detected by PCR at low level
What action would you take?
Gather information -
- donor history
- any evidence of CMV disease e.g retinitis, colitis, pneumonitis
- if on CMV prophylaxis - is this breakthrough disease
- previous viral loads
- screen other infections
Treat - IV v oral would depend on disease severity
If on letermovir - switch to valganciclovir 900mg BD treatment
If on valganciclovir prophylaxis 900mg OD - switch to 900mg BD treatment
Consider resistance testing if breakthrough infection
what is the name of the new RSV monoclonal antibody approved in 2023
Nirsevimab - protects for 5 months. Longer half-life
Palivizumab requires injection every month
Give during RSV season to high risk babies aged <2
e.g chronic lung/ heart disease, immunocompromised
Who should receive the new RSV vaccine?
Not decided in UK
>75 years initial rollout
In future:
Children <2
Pregnant women weeks 32-36 gestation
In USA:
Children <2
Pregnant women weeks 32-36 gestation
>60 years old
Measles
What is the case definition?
Fever
Plus:
maculopapular rash
Plus one of:
cough
coryza
conjunctivitis
What is the DDx for maculopapular rash?
Measles
Rubella
EBV
CMV
HHV6
HHV7
Parvo B19
S. Aureus
GAS
Varicella vaccine
What is the name of the strain used?
How is it grown?
Oka strain
Live attenuated virus
Grown in MRC5 fibroblasts
What new developments have there been in oral polio vaccine?
novel monovalent OPV2
nOPV2
protection against type 2 variant outbreaks - which is vaccine derived
Type 1 strain is only 1 circulating in wild
more stable genetically, so less likely to cause vaccine associated paralytic polio
Describe the RSV vaccine?
mRNA vaccine
directed against Pre-F protein
What are indications for RSV vaccine?
Initially >75 year olds
Then will be:
>60 years old
<2 years old
pregnancy
Which countries still have wild polio infection?
Pakistan
Afghanistan
Polio Type 1 is only one circulating in wild
What is incubation period of TBE?
7-14 days
What is case fatality rate of TBE?
1-2% for European subtype
20% for Far Eastern subtype
Who is recommended to have TBE vaccine?
Those moving to endemic area
with high risk of exposure e.g outdoor working/ woodlands
What vaccine is available for Dengue?
Denvaxia quadrivalent
based on YF 17D strain - live attenuated
Only give if have proven Dengue infection previously
80% protection against severe disease
