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Virus and Disease. Chapter 19.3. Viruses and Disease—Colds/Flu/Herpes. _ Transitory virus _ : infects organism and are killed by the immune system. EX: Rhinovirus- causes _ cold _ Influenza virus - causes the flu
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Virus and Disease Chapter 19.3
Viruses and Disease—Colds/Flu/Herpes • _Transitory virus_: infects organism and are killed by the immune system. EX: Rhinovirus- causes _cold_ Influenza virus - causes the flu • _Permanent virus_: DNA or RNA are inserted into the host genetic material and become part of host DNA. EX: Herpes symplex I , II -inserted into _host_ genetic material -usually _dormant_ -gets inflamed when virus is reproducing and releasing lots of virus particles
Viruses and Disease—HIV/AIDS • HIV - goes after white blood cells (T cells) -is an RNA virus • HIV has receptors that are like the white blood cells own receptors, so the virus is invited in • HIV has an enzyme called reverse transcriptase, which makes the viral genetic material become part of the host cells DNA. • Once infected, the immune cells may burst -producing more daughter viral cells- or they may continue to reproduce regularly until some later time. • HIV -hard to transmit -has to be transmitted through body fluids -Cocaine increases viral replication by 3 times -Cannot get it from mosquitoes because it cannot be active in insects
Viruses and Disease—Spanish Flu (Misnamed) • Early 1918 - started as a typical flu -mutated into a virulent (disease causing) form • Fort Riley Kansas- 1st known cases during WWI -lots of men on base went to Europe from the US. -In Europe it mutated • People started dying -dizzy -projectile nose bleeds -severe respiratory problems -coughed up pints of green-yellow pus -big purple blisters -within hours you could be dead -autopsy- nothing left of lungs
Viruses and Disease—Spanish Flu (Misnamed) • -Flu spread through Europe and Asia becoming a pandemic (worldwide epidemic) -8 million people died in Spain -12 million died in India -600,000 died in the US (MORE THAN DIED IN THE CIVIL WAR) -22 million people died worldwide within 1 year. -30 million people had complications but did not die -Pittsburg- 5000 people died in one weekend • so many people got this flu because it spread through the air. • finally it mutated back
DIRECT RESPONSE TO FLU • -C.D.C. –Center for Disease Control (contain epidemics before they spread) • -W.H.O. - World Health Organization (collect new viral strains) • -People-animal relations help infestations to occur -Viruses pop up in birds which can live in pigs (not humans). -Virus mutates and humans can get it. -Rain forest- stressed environment