Respiratory viruses Flashcards
(24 cards)
what is the most common cause of upper respiratory tract infection? what family of viruses is this?
Rhinovirus (gives you the common cold), which is an RNA picornavirus
why is there no vaccine for rhinovirus?
bc there are over 100 serological subtypes
the fact that there are 100 serological subtypes of rhinovirus means what two thing?
- no vaccine
2. you can be infected with it over and over
rhinovirus is synonymous with…
the common cold
unlike all other picornoviruses, rhinovirus is…
acid labile, which means that the virus is destroyed by stomach acid/bile and can’t cause GI ifxns
what does it mean that rhinovirus, unlike all other picornoviruses, is acid labile?
it means that rhinovirus gets destroyed in the stomach, and has no GI side effects. All other picornoviruses infect the GI tract!
influenza virus, which causes respiratory symptoms, is RNA or DNA? is ss or ds? enveloped or not? is what group?
ssRNA virus, enveloped, orthomyxovirus
the influenza virus codes for what two proteins
Hemagglutinin (viral entry)
Neuraminidase (progeny virion release)
the influenza virus makes what protein for viral entry
hemagglutinin
the influenza virus makes which protein for progeny virion release?
neuraminidase
what is hemagglutinin
protein made by influenza virus that allows for viral entry into the cell
what is neuraminidase?
protein made by influenza virus for progeny virion release
influenza’s segmented genome allows it to…
recombine with other strands of influenza—> increase virulence, lead to genetic shifts (when it’s combined with RNA from another species!) (pandemics)
genetic drifts are caused by
point mutations in the genome
what’s worse a genetic shift or drift?
genetic shift (pandemic) genetic drift (epidemic)
which virus group mainly infects children, giving them respiratory problems? what are the 4 subtypes of that virus group?
Paramyxovirus
- parainfluenza (croup)
- Mumps
- Measles
- RSV
which paramyxovirus causes croup?
parainfluenza
which paramyxovirus causes bronchiolitis in babies
RSV (respiratory syncytial virus)
** syncytial comes from the fact that surface F (fusion) protein on the virus causes respiratory epithelial cells to fuse, forming multinucleated giant cells (syncytial cells).
paramyxoviruses (parainfluenza, measles, mumps and RSV) contain was virulence factor? what does it do?
surface F (fusion) protein– causes respiratory epithelial cells to fuse, forming multinucleated giant cells (syncytial cells).
Do we get vaccinated for influenza A to protect us from genetic shift or drift?
Drift– minor changes in surface antigens due to point mutations. Though shift occurs (recombinant dna), the reality is that our vaccines can’t really protect against them.
is influenza a live vaccine or a killed one?
killed
can an immunocompromised pt get a flue vaccine?
yes, bc it’s a killed vaccine.
how many segments in influenza virus?
8
the fact that influenza is segmented (8 segments) means that it can undergo
genetic reassortment (where segments are switched in and out)
