Influenza Pathophysiology 2012 (1)

Genetic parts of currently circulating human

Info iconThis preview shows pages 30–39. Sign up to view the full content.

View Full Document Right Arrow Icon
Genetic parts of currently circulating human influenza strains came from birds
Background image of page 30

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Avian, Swine and Human Influenza Typically wild birds don’t get sick from influenza Virus is carried in their intestines Transmission to other animals or humans occurs via contaminated saliva, nasal secretions and feces What’s the Connection?
Background image of page 31
Avian, Swine and Human Influenza What’s the Connection? Bird Human Rarely does an avian flu directly transmit to a human Example: “Spanish flu” H1N1 Requires direct contact with infected birds Must acquire the ability to spread from human to human Bird Mutation Mutation Human Viruses can mutate over time and adapt to conditions in which they can infect and spread amongst humans ______________________________________________________________________ ______________________________________________________________________ Bird Re-Assortment Human Re-assortment can be considered “genetic sharing”
Background image of page 32

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Avian, Swine and Human Influenza Re-assortment and “Genetic Sharing” Wild or domestic Bird Animal or Human H1N1 H2N2 Re-assortment New Virus!!! H1N2 Animal or Human Host Examples: “Hong Kong Flu” and “Asian Flu
Background image of page 33
Influenza A Gene Pool in Wild Birds Every influenza A virus has: A gene encoding for 1 of 16 possible hemagglutinin surface proteins A gene encoding for 1 of 9 possible neuraminidase surface proteins Eight (8) genes encoding for additional functional proteins In 1918, an avian flu (H1N1) adapted to infect both humans and pigs 1918 H1N1 Human Spanish Flu 1918 H1N1 Swine Spanish Flu
Background image of page 34

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
1918 H1N1 Human Spanish Flu Influenza A Gene Pool in Wild Birds Current H1N1 Seasonal Flu + 1957 Pandemic Human H2N2 “Asian Flu” Periodic Antigenic Drift Genetic re-assortment with H2 and N2 donated from “gene pool” In 1957, a new influenza strain was identified (H2N2) and resulted in a pandemic killing 70,000 in the US alone Antigenic Shift
Background image of page 35
Influenza A Gene Pool in Wild Birds + 1957 Pandemic Human H2N2 “Asian Flu” Genetic re-assortment with H3 donated from “gene pool” In 1968, a new influenza strain was identified (H3N2) and resulted in a pandemic killing 35,000 in the US Became extinct by 1975 1968 Pandemic Human H3N2 “Hong Kong” Flu Antigenic Shift
Background image of page 36

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Current H3N2 Seasonal Flu + Periodic Antigenic Drift Genetic re-assortment with genes donated from 3 viruses Antigenic Shift 1968 Pandemic Human H3N2 “Hong Kong” Flu Eurasian Swine H1N1 Swine H1N2 + 2009 Pandemic Swine H1N1
Background image of page 37
Pandemic H1N1 Influenza April 2009 First case of novel H1N1 reported July 11, 2009 A pandemic is declared by WHO CDC estimates of H1N1 activity in the United States 4/2009 – 4/2010: About 61 million people were infected with H1N1 About 274,000 H1N1-related hospitalizations occurred About 12,470 H1N1-related deaths occurred Statistics
Background image of page 38

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Questions ???
Background image of page 39
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page30 / 39

Genetic parts of currently circulating human influenza...

This preview shows document pages 30 - 39. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online