Viral Respiratory Infections Flashcards
what is the Ro value in epidemiology?
it describes how many people a single person with a well known virus can infect
what is the disease with the highest Ro value?
measles
what is the structure of rhinovirus?
single stranded RNA with small protein shell
what is a rhinovirus in first year of life associated with later in life?
chronic lung disease like COPD of CF…but especially adolescent asthma
why is there not a vaccine for rhinovirus?
because there are over 100 serotypes
can rhinovirus cause pneumonia?
you betcha
where do influenza viruses originate from? what is this called?
they originate from animals…called zoonotic virus
does RSV have a vaccine?
NO
does RSV have specific antivirals?
NO
does measles have specific antivirals?
NO
does measles have a vaccine?
YES…super good
what is a common problematic cooccuring disease with influenza virus?
bacterial superinfection
what four bugs commonly cause bacterial superinfection?
staph A
strep pneumo
group A strep (pyogenes)
post infection, how long does it take you to develop serum antibodies against influenza?
2-3 weeks
what is common class of influenza that infects us?
type A influenza
is type B influenza a zoonotic virus?
no…only in humans
what age group does type B influenza affect mainly?
mainly children
what is the makeup of the influenza virus?
segmented RNA virus
what is the role of neuraminidase in influenza?
it cleaves cyalic acid
what are the four descriptors in order in infleunza nomenclature?
type, location of origin, strain number, year of isolation
what animal do most influenza viruses start in?
aquatic birds
what is antigenic drift?
gradual adaption through mutation of zoonotic viruses that allow human infection and transmission
what is antigenic shift?
re-assortment of the segmented genome potentially allowing swapping of genes between different virus types (worse than drift)
how often does antigenic shift happen?
between 10-40 years per one
what is the predominant lineage of influenza B?
victoria lineage
what are the two vaccine options for flu?
inactivated dead viral shot
live attenuated flu mist
what does it mean for there to be a universal flu vaccine?
it means you get one vaccine that prevents you from drifting virus
what is the structure of RSV? what is its other name?
paramyxoviruses
eneveloped non segmented negative sense RNA
what ages does RSV usually affect?
infants and immunocomp elderly
how long does immunity last to RSV?
only like 2-3 months
what portion of the airways does RSV infect?
bronchioles
RSV infection of bronchioles leads to what?
airway obstruction
what is the treatment for RSV?
supportive care mainly…there are non specific antivirals and pasisvely administered immunoglobulins
are steroids or bronchodilators used with RSV?
no…
what cells of the respiratory tract do viruses infect?
the epithelium
explain how virus infections can lead to bacterial super infections
the virus gets into epithelium that gets infected enough that it clears out a space via necrosis and bacteria can settle
name the three important molecules on the outside of the influenza virus?
neuraminidase
hemagluttinin
M2 ion channel
explain why most influenza viruses in avian species do not make their way into human species
the receptors fro hemagluttinin on sialic acid for avian species is a 2,3 linkage but humans can only do 2,6 linkages between sialic acid and galactose
what is the mechanism of Xofluza?
it inhibits the influenza virus from being able to make its own mRNA
what time of year is RSV common?
late fall into early spring
name the five symptoms of measles
fever cough macular red rash over most of body photophobia nausea
how long does measles immunity last? can measles virus drift?
lifelong
no
what is the name of the rash in measles?
Kopliks spots
where does the rash come from in measles?
infection of dermal capillary endothelial cells
describe the pattern of disease from inoculation to transmission of measles in an individual
start by inhaling measles and it enters the lungs…from here the virus goes to lymph nodes and enters systemi circulation leading to the many symptoms…eventually works it way back to lungs and can cross back into airways to be coughed out and transmitted
