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Bird flu virus
Avian influenza is an infection caused by avian (bird) influenza (flu)
viruses. These bird flu viruses occur naturally among birds. Wild birds
worldwide carry the viruses in their intestines, but usually do not get
sick from them. However, avian influenza is very contagious among birds
and can make some domesticated birds, including chickens, ducks, and turkeys,
very sick and kill them.
There are many different subtypes of type A influenza viruses. These subtypes
differ because of changes in certain proteins on the surface of the influenza
A virus (hemagglutinin [HA] and neuraminidase [NA] proteins). There are
16 known HA subtypes and 9 known NA subtypes of influenza A viruses. Many
different combinations of HA and NA proteins are possible. Each combination
represents a different subtype. All known subtypes of influenza A viruses
can be found in birds.
Usually, "bird flu virus" or “avian influenza virus” refers
to influenza A viruses found chiefly in birds, but infections with these
viruses can occur in humans. The risk from avian influenza is generally
low to most people, because the viruses do not usually infect humans.
However, confirmed cases of human infection from several subtypes of avian
influenza infection have been reported since 1997. Most cases of avian influenza
infection in humans have resulted from contact with infected poultry (e.g.,
domesticated chicken, ducks, and turkeys) or surfaces contaminated with
secretion/excretions from infected birds. The spread of bird flu viruses
from one ill person to another has been reported very rarely, and has been
limited, inefficient and unsustained.
“Human influenza virus” usually refers to those subtypes that spread widely
among humans. There are only 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 might
adapt over time to infect and spread among humans.
During an outbreak of bird flu among poultry, there is a possible risk
to people who have contact with infected birds or surfaces that have been
contaminated with secretions or excretions from infected birds. It is only
if the birf flu virus mutates to become contagious amongst humans that it
could spread easily between the populations of the world, and that is the
potential global bird flu pandemic that
is worrying so many health agencies around the world.
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bird flu virus - Google News
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Swine flu deaths top bird flu toll - Financial Times
Tue, 30 Jun 2009 04:27:12 GMT
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Cambodia confirms first case of new flu - Reuters
Wed, 24 Jun 2009 13:03:21 GMT
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Two more flu A/H1N1 deaths reported in Aisa-Pacific region - Xinhua
Fri, 03 Jul 2009 16:25:32 GMT
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Wayne Marasco: A Shot at a Universal Flu Vaccine - U.S. News & World Report
Tue, 30 Jun 2009 19:33:48 GMT
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Vietnam A/H1N1 flu cases increase to 181 - Xinhua
Fri, 03 Jul 2009 03:37:01 GMT
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Experts divided on treatment for birdflu patients - Reuters
Tue, 23 Jun 2009 05:27:25 GMT
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Egypt extends dorm lockdown after H1N1 spreads - Reuters
Tue, 09 Jun 2009 14:04:21 GMT
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Novavax Wins Flu Vaccine Deal in Spain; Shares Surge - Washington Post
Wed, 01 Jul 2009 04:17:25 GMT
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Op-Ed Contributor - New York Times
Wed, 10 Jun 2009 13:41:50 GMT
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Battelle a major fighter of swine flu - Columbus Dispatch
Sat, 04 Jul 2009 10:20:46 GMT
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