Transcript BIRD FLU and YOU Brookings Register, November 2005 INFLUENZA A • There are THREE known A subtypes of influenza viruses (H1N1, H1N2, and.

BIRD FLU and YOU
Brookings Register, November 2005
INFLUENZA A
• There are THREE known A subtypes of influenza
viruses (H1N1, H1N2, and H3N2) currently
circulating among humans.
• It is likely that some genetic parts of current human
influenza A viruses came from birds originally.
• Influenza A viruses are constantly changing,
and they can adapt over time to infect
and spread among humans.
Image from: http://www.msjanie.com/articles/sickness.jpg
AVIAN INFLUENZA
(Bird Flu)
• Infection caused by bird flu virus
• Occurs naturally in wild birds
• Wild birds carry virus in their intestines,
but usually don’t get sick
• Very contagious among birds
• Can make domesticated birds
(chickens, ducks, turkeys)
very sick and kill them
Image from: http://www.friedmanarchives.com/Nepal/images/Chicken%208x10%20300%20dpi.jpg
Why worry about Bird Flu if it is a
bird disease?
• Three strains of bird flu (H5N1, H9N2 and H7N7)
have been transmitted to people
• H5N1 is genetically similar to the H1N1 virus
strain that caused the 1918 Flu pandemic.
• Most cases have occurred in previously
healthy children and young adults.
• It has a high mortality rate
(50% of the humans infected so far have died)
H5N1
http://fotservis.typepad.com/photos/egypt/chicken_smoke.html
• H5N1 virus does not usually
infect people, but more than
140 human cases have been
reported by the World
Health Organization since
January 2004
• Most of these cases
resulted from people having
direct or close contact with
infected poultry or
contaminated surfaces
Why worry about H5N1?
•So far, the spread of H5N1 virus from person to
person has been rare and has not continued
beyond one person.
•Nonetheless, because all influenza viruses have
the ability to change, scientists are concerned that
H5N1 virus one day could be able to infect
humans and spread easily from one person to
another.
•Because these viruses do not commonly infect
humans, there is little or no immune protection
against them in the human population.
WHY WORRY?
• A few cases of human-to-human spread of H5N1 have
occurred, but have not spread beyond this initial
infection
• If H5N1 virus were to gain the capacity to spread easily
from person to person, a worldwide outbreak of
disease could begin.
• In the current outbreaks in Asia and Europe, more than
half of those infected with the virus have died.
Where in the world is H5N1?
Influenza A (H5N1), has caused infections in
birds and HUMANS in Asia and Europe
(Cambodia, Tibet, Mongolia, Indonesia,
Malaysia, Thailand, Vietnam, Kazakhstan,
Siberia, Ukraine, and recently Turkey.
Image from: http://www.stanford.edu/group/virus/uda/
Flu pandemics
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•
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•
1918 Spanish flu killed 50 million
1957 Asian flu killed around 1million
1968 Hong Kong flu killed 1million
1976 Swine flu was a “dud”
Image from: http://plainbookofmormon.com/images/graves.jpg
Influenza Pandemic of 1918
• Infected 1/5 of world’s population and killed
somewhere between 20 and 40 million people
• It has been cited as the most devastating
epidemic in recorded world history.
• More people died of influenza in a single year
than in four-years of the Black Death Bubonic
Plague from 1347 to 1351.
• Known as "Spanish Flu" or "La Grippe" the
influenza of 1918-1919 was a global disaster.
http://www.stanford.edu/group/virus/uda/fluresponse.html
FLU PANDEMIC
of 1918
• Infected 28% of all Americans
• An estimated 675,000 Americans died
(ten times as many as in the World War I)
• An estimated 43,000 U.S. servicemen mobilized for
WWI died of influenza
(1/2 of casualties were from flu NOT the war itself)
http://www.sdhistory.org/arc/flunewspapers.htm
EVEN IN
SOUTH
DAKOTA
28% of people who died
in South Dakota in 1918
died from INFLUENZA
http://www.sdhistory.org/arc/flunewspapers.htm
PRECAUTIONS
http://www.sdhistory.org/arc/flunewspapers.htm
INFLUENZA A (FLU)
COMMON SYMPTOMS
• Fever
• Cough
• sore throat
• and muscle aches
OTHER POSSIBLE
•
•
•
•
other infections
pneumonia
severe respiratory diseases
severe and life-threatening complications
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PREVENTION
This is NOT an airborne disease
so there are ways that you can protect yourself,
• Wash your hands
• Use cough etiquette
• Stay home if you're sick
• Stay away from people who
are sick
http://www.askthebrain.com/pics/588/Cough.jpg
Will a Flu Shot now protect me
from Bird Flu?
• The viruses in flu vaccine change each year
based on which strain is expected to be the
problem
• Current vaccine protects against
2 strains of A (H3N2 & H1N1)
1 strain of B
NOT AGAINST H5N1
• It takes about 2 weeks after vaccination for flu
antibodies to develop in your body
Image from: http://www.omedon.co.uk/influenza/beans/influenza%20virus.jpg
Can we make a NEW VACCINE?
• There currently is no
commercially available vaccine
to protect humans against
H5N1 virus
• Research studies to test a
vaccine to protect humans
against H5N1 virus began in
April 2005, and a series of
clinical trials is under way
http://news.bbc.co.uk/2/hi/europe/3524824.stm
http://www.jsonline.com/news/image/flu010700.jpg
CAN OTHER MEDICINE HELP?
• The H5N1 virus that has caused human illness
and death in Asia is resistant to amantadine and
rimantadine, two antiviral medications commonly
used for influenza.
• There currently is no commercially available
vaccine to protect humans against H5N1 virus
that is being seen in Asia and Europe.
Image from: http://www.stanford.edu/group/virus/uda/fluscimed.html
Tamiflu
Anti-viral medicine
• Can be used for prevention OR
once you have virus
• One pill protects you for one day
• Experts believe the first wave in a
given area would last up to 100
days.
• You would need to stockpile about
100 doses of Tamiflu and start
taking them from the moment you
hear the virus is circulating in your
region.
• Shortage right now!
http://www.cbc.ca/news/background/avianflu/avian-faqs.html#q8
WHAT IS BEING DONE?
• World Health Organization (WHO) is
monitoring ALL REPORTED cases
around world
• EARLY detection and intervention
of first human to human infection is
VITAL to STOPPING the spread and
preventing a world wide EPIDEMIC
WHAT IS BEING DONE?
• Several countries are currently testing a
vaccine against H5N1
• Production of anti-virals (Tamiflu) has been
increased
• Public education about prevention and early
detection
• Plans by Governments for action in case of
epidemic