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10 Cards in this Set
- Front
- Back
What class of virus is influenza and what are its chief characteristics?
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Orthomyxoviridae, Group V, 3 types - A, B, C, able to mutate and so antigenic drift and shift occurs, segmented genomes
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How does influenza bind to the cell?
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H protein attaches to sialic acid, endosomal entry, low pH membrane fusion
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What are some of the important differences between influenza A, B, and C?
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A - humans, pigs, horses, other mammals, birds, B - humans only, C - humans, pigs
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What are the concerns of H5N1?
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avian flu - jumped from birds to humans, only H5 to infect humans, 33% fatality, single insertion could cause spread to brain and heart
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Why are the young and very old most susceptible to Influenza?
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young - croup, otitis, secondary bacterial infxn, very old - pneumonia, secondary bacterial infxn, preexisting conditions exacerbated
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What does influenza do to the lungs?
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it destroys the cilia of ciliated columnar epithelium destroying cleaning system of lungs - mucus builds up
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How is influenza spread? How many particles are sneezed or coughed out?
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respiratory droplets, 100,000 to 1 million viruses per droplet
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Where does the influenza virus replicate and what are its unique features for taking over the cell?
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in nucleus, exploits host nuclear splicing for viral mRNA, suppresses interferon release
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When were major influenza epidemics?
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1918-1919 - Spanish flu, 1957-1958 - Asian flu, 1968-1969 - Hong Kong flu
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Where and how do new strains of influenza develop?
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influenza A viruses from swine and avian infect same cell creating antigenic shift
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