Influenza Flashcards
What is influenza?
acute, febrile respiratory disease (NOT GI upset and NOT mild respiratory illness)
Influenza virus is an ____ virus with a segmented genome.
enveloped ssRNA
The influenza virus genome is made up of _____.
8 pieces of ssRNA
Two of the best characterized viral proteins are the ____ and _____ glycoproteins, which identify the subtype of influenza based on their combination in the viral coat.
hemagglutinin (H); neuraminidase (N)
There are 3 types of influenza viruses: ___ and ____, which circulate in the pop. every year, and ____ that causes a mild/clinically insignificant illness.
A and B; C
How do repeated influenza epidemics persist?
type A and B viruses undergo constant and rapid change due to antigenic drift
When does antigenic drift occur? Why?
only after a strain has become established in humans; it has adapted to the host Abs
Influenza virus is an RNA virus with a ____ genome.
segmented
What is antigenic drift?
gradual change in the virus via mutations, substitutions, or deletions in aas that make up the H or N surface antigens
What is antigenic shift?
a completely novel hemagglutinin or neuraminidase gene segment is introduced
Where does the new gene segment in antigenic shift come from?
other host species (birds or swine)
How is influenza transmitted?
respiratory route, contamination of hands and inanimate objects
What is the incubation period for influenza?
1-3 days
What are the s/s of influenza in adolescents and adults?
acute onset fever, chills, myalgias, headache, cough
What are the s/s of influenza in a neonate?
resembles bacterial sepsis, including lethargy, decreased eating, mottling
