Exam2Lec8RNAviruses Flashcards
What is the genome and sense of picornavirus
RNA genomes and positive sense, ss
What is the capsid symmetry of picornavirus
Iscoahedral capsid symmetry
Where is the replication of picornavirus
Cytoplasmic
T/F picornavirus has variable host range
True
What is the illness of picornavirus
Respiratory, GI, cardiac, hepatic illness
“common cold” (rhino, entero)
What are the exact examples we do for class?
Rhinovirus (HRV14)
EV-D68
Poliovirus
What is the tropism of entero-
GI tract (includes coxsackie A,B and echo)
What is the tropism for coxsackie
A: skin, mucous membranes
B: heart, lungs, liver
What is the tropism for Rhino-
URT
What is the tropism for Hep A
Liver
What does the picornavirus family cause?
Respiratory, GI, cardiac, hepatic illness
Positive stranded viral genomic RNA is what?
mRNA and considered infectious
What allows the facilitates interaction with ribosomes
Viral RNA has a 5’ internal ribosome entry site (IRES) sequence that facilitates interaction with ribosomes.
What is the problem and resolution of single segment?
Problem: single gene
Resolution: viral protease
- Clips polyprotein into smaller functional subunits
What is an example of viral protease?
Poliovirus
3c=protease
What is not capped in genomic RNA , and has what instead?
5’ end of genomic RNA is not capped, instead has viral VPg protein bound
What is the structure of Rhinovirus
ss(+) RNA, icosahedral
Serotypes:>200
What is the transmission of Rhinovirus
Fomite
Respiratory (surgical / N95)
Sensitive to low pH
Cannot grow above 33oC ⭐️
What is the seasonality of Rhinovirus
Peaks in Fall (predominant), Spring
More severe infection in Winter
When you see rhinovirus, what should you think?
Common colds
Makes up 1/3 to 1/2 of all acute respiratory infection in humans
What is the common cold symptoms
Coryza/rhinitis: congestion, runny nose
Pharyngitis: sore throat
Cough
Low-grade fever, if any
Causes of common cold
Rhinoviruses
Coronaviruses
Parainfluenza viruses
What should be used for large droplets
surgical mask
what should be used for small droplets
N95
Common cold is what type of illness
Common cold is a self-limited illness.
Common colds account for how many respiratory infections in humans
one-third to one-half
What is the virus that is similar to rhinoviruses
Enterovirus D68
What is the structure of Enterovirus D68
Structure: ss (+) RNA, icosahedral
What does Enterovirus can cause
EV-D68 can cause mild to severe respiratory illness.
Mild symptoms may include fever, runny nose, sneezing, cough, and body and muscle aches.
Severe symptoms may include wheezing and difficulty breathing.
Linked to acute flaccid myelitis (AFM) ⭐️
What is unique to EV-D68 disease
Linked to acute flaccid myelitis (AFM) ⭐️
What is seasonality in Enterovirus D68
Peaks In summer.fall
- earlier than rhinovirus
Where has the EV D68 have been recently
US Europe and Asia
What does poliovirus infect
Infects cells in the gut/intestinal lining, specifically the associated lymphoid tissue (GALT)
What are the symptoms of Poliovirus
Typically, asymptomatic infection (~70%)
Mild symptoms: sore throat, fever, malaise (~25%)
Rare CNS involvement: aseptic meningitis
Can progress to poliomyelitis
What is unique about poliovirus
Rare CNS involvement: aseptic meningitis
Can progress to poliomyelitis
What is poliomyelitis
virus targets CNS= paralysis
What is the poliovirus vaccine in the US
4 doses of inactivated polio vaccine (IPV, Salk)
What does the current vaccine (US) prevent?
ONLY POLIOMYELITIS, not infection
What is the polio vaccine out if the US
Live attenuated vaccine (OPV)
Bivalent (Types 1 and 3): Type 2 eradicated in 1999
What is the problem of the live attenuated vaccine out of US
can cause circulating vaccine- derived poliovirus (cVDPV)
- mostly type 2
Where is poliovirus endemic in?
Pakistan and Afghanistan
What is the Genomes of caliciviruses family
RNA Genomes
what is the sense of caliciviruses family
positive sense, ss
What is the capsid symmetry of Caliciviruses Family
Icosahedral
What is the replication of caliciveuses family
Cytoplasmic
What is host range of Caliciviruses family
narrow host range
what illness does Caliciviruses family cause
GI illness
What is the most common cause of viral gastroenteritis
Noroviruses