IMM250H1 Lecture Notes - Lecture 7: Viral Envelope, Upper Respiratory Tract Infection, Rna Virus
Document Summary
Not a mild cold rapid onset, often bed-ridden for a few days, fever, cough and severe muscle aches. Stomach flu is caused by other viruses, not influenza virus. Tested guinea pigs: virus is more readily transmitted under cool dry conditions. At higher humidity and temperature, droplets are larger and settle faster, need more direct contact. Under cooler, drier conditions can spread through air. Influenza c common but seldom causes disease. Pleomorphic (the envelope can occur in spherical and filamentous forms) Febrile (symptoms of fever), respiratory illness with systemic symptoms. Ha hemagglutinin (h1-16: h1, h2, h3 human strains, h5n1 current bird flu , binds to cells, allows entry. March 13, 2013: needed to get out of cells. Virus ha (hemagglutinin) attaches to terminal sialic acids on surface carbohydrates. Cleavage of newly synthesized ha (hemagglutinin) by enzyme in lung epithelial cells, but not other cells restricts site of virus activity to human lung.
