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9 Cards in this Set
- Front
- Back
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Orthomyxoviridae
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Influenze A B C
SS RNA, negative polarity, 8 segments (A and B), 6 segments (C). Helical Nucleocapsid 1 protein per segment H and N are envelope glycoproteins RNA Dependent - RNA polymerase in Nucleocapsid |
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Influenza
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Nucleocapsid and M protein
Upon proteolytic cleavage of H - activate infectivity N is important in budding and lowering viscosity of mucus |
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nfluenze Epidemics and Pandemics
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H - major antigen for immunity - 11 subtypes
N - 8 subtypes antigenic drift is point mutations in H and N - this leads to epidemics antigenic shift is when there is reasortment between human and animal populations - this causes pandemics (every 10 years) - NO AB's |
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Pathogenesis of Influenza
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spread by droplets
epithelial cells lysed N peptide lowers the viscosity of mucus cell destruction and viremia causes fever Ig A is most important in immunity - short lived |
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Influenza B
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Less frequent shif and drift
infects children mostly Reye's Syndrome - noninflammatory encephalopathy, fatty degeneration of liver, polyneuritis, hypoglycemia (clinically - vomittting, and neuro dysfunction - Aspirin related) guillain -barre - paralysis due to demylination |
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Antiviral drugs
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not a substitute for vaccination
Amantadine and rimantadine - blocks uncoating. Give to those with egg hypersensitivity Ribavirin - inhibits RNA synthesis (not used) there is resistence to Adamantanes reported world wide Zanamivir and Oseltamivir - Neuraminidase inhibitor |
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Seasonal Vaccine
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split vaccine to persons 6 months and older
combo of type A and B start vaccine in october and november TIV recommended for 65 years plus healthy children 6 - 35 if there is adequate supply Split vaccine (subunit) - split of H and N antigens nontoxic nonpyrogenic not contaminated with egg proteins Intranasal LAIV or Flumist. will not replicated in lungs, only in the upper respiratory tract 2 doses 6 weeks apart children 2 years or older, and adults up to 49 not for comprimised/pregnant individuals |
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What are the 2 reasons flu vaccines may be required in the age of bioterrorism?
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differentiate against anthrax infection
could protect somewhat from weaponized flu |
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Replication of Flu virus
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cytoplasmic and nuclear phases
RNA is copied from negative to postive strand - which acts as mRNA or a template for replication mRNA is shorter than (-) RNA mRNA has a 3' poly A tail DONATED cellular RNA short cap at the 5' end each mRNA codes for 1 protein there is formation of a replicative intermediate nucleocapsid acquires envelope |
