Bird Flu Links
Hopefully this list will
help dispel rumours and give more factual information on which to go on
to protect our birds.
Bird Flu Epidemic is a Hoax
Cross posting authorized and encouraged by NAWA
Flu is for the Birds!
by the National Avian Welfare
Human influenza is a
highly contagious disease. Most of us have had the flu multiple times in
our lives. In the
, influenza epidemics occur nearly every winter and are responsible for
a substantial amount of illness and deaths. Approximately 114,000
hospitalizations and 20,000-50,000 deaths occur in the
on an annual basis as a result of the flu (http://www.cdc.gov/mmwr/preview/mmwrhtml/ss5107a1.htm).
If influenza is so
easily transmissible, why aren't more people catching the bird flu
directly from birds? The reason is that birds and humans are different.
The qualities that allow the virus to easily infect birds don't work
well on humans.
Although it's true that
avian flu viruses can become human flu viruses, the typical way a flu
virus makes the jump from birds to humans is by infecting a pig that
just happens to have a concurrent infection of human flu virus - 2
different viruses in the same animal at the same time. Pigs are more
easily infected by both types of viruses and they serve as a sort of
mixing pot. Different types of influenza viruses can exchange genetic
material when they are exposed to each other in the same host. This is
called antigenic shift.
Antigenic shift allows
for large amounts of new genetic information to be acquired by the avian
flu from the human flu virus when they are exposed to each other. If the
avian flu virus acquires the genetic factors that allow it to easily
pass from human to human, then it is possible for the avian virus to
make the jump to become a human influenza.
Because birds and
humans are very different, there are generally multiple factors that
must be acquired in order for the virus to make the transition from
avian to human flu. The actual factors that allow an avian flu virus to
easily infect birds may prevent it from easily infecting humans.
Additionally, the factors that allow the avian flu viruses to easily
infect humans are likely to alter more than just the viruses' ability to
infect humans. It is also likely to alter the virus's impact on the
human body. In the case of H5N1, this means it is just as likely to
become nothing more than the standard flu, as opposed to the killer flu,
if it makes the jump to human influenza.
One of the reasons
is a breeding ground for influenza is the animal husbandry practices
that are used there. Poultry can be brought to markets where they are
exposed to poultry from other farms, and live birds are brought back
home if unsold. Ducks, poultry and pigs are allowed to commingle on the
farms where there is very little biosecurity. Poultry are allowed to
free-range and domestic ducks are allowed to graze in open wetlands
where wild waterfowl visit. This increases the likelihood that avian flu
viruses which are common in wild waterfowl can mix with human flu
viruses which are common in pigs. This allows for a shuffling of genetic
traits between the different strains of viruses which creates new
strains as a result. If the new strains have the ability to infect
humans easily, then the farmer, or other people around the livestock,
will catch it and the virus spreads through the human population from
practices in the
are not conducive to the mingling of avian flu strains with human flu
strains. If H5N1 arrives in the
via migrating waterfowl, it is not going to have the opportunity to
acquire the traits necessary to become a human flu virus here.
Influenza viruses also
change their genetic properties by simple random mutations. This process
is called antigenic drift, in contrast to antigenic shift. Antigenic
drift is responsible for small changes in the genetic properties of the
virus. All influenza viruses mutate regularly and thereby undergo
antigenic drift constantly. This is the reason we can't carry immunity
to the flu from one year to the next. This year's flu will be different
enough from last year's flu so that our immune system will not recognize
it or have the proper antibodies to fight it off. Although antigenic
drift can result in changes in pathogenicity in avian flu virus strains,
it rarely, if ever, results in the significant genetic changes required
to allow an avian flu virus to make the jump to becoming a human flu
It is theoretically
possible for an avian flu virus to accumulate enough mutations through
antigenic drift to gain the ability to infect humans easily, without
antigenic shift or an intermediate host involved, but this generally
requires a specific series of mutations to happen. Because more than a
single mutation is involved, the odds of this happening are very small.
Any single mutation in the direction that may lead to an avian flu
becoming a human flu is likely to cause that avian flu strain to be less
capable of infecting birds and thereby surviving long enough to gain the
additional mutations necessary to complete the jump. Even if an avian
virus strain was capable of accumulating the correct series of mutations
to become a human influenza, those genetic changes are also just as
likely to reduce the impact the virus has on the human body.
In order for an
influenza virus to be easily spread throughout the human population and
result in a pandemic, it must be mild enough for people to be able to go
out and spread the virus once they are infected. If the virus kills its
victims quickly, as is the case with the current strain of H5N1, there
will be dramatically less opportunities for the virus to be transmitted
from the victim to a new host. The infection becomes what
epidemiologists call "self-limiting". Because a victim quickly
becomes too sick to get out in public, the virus does not have the
chance to spread to a large number of people. This further illustrates
why the genetic changes required for H5N1 to become a human flu virus
are unlikely to cause it to become the deadly killer that the media is
playing it up to be.
The current pattern
displayed by H5N1 illustrates how difficult it is for avian flu viruses
to infect humans. Despite the fact that there have been millions of H5N1
infected poultry in
in the past few years, only a little over one hundred human H5N1 cases
have been reported. This is a very small number in comparison to the
probability of numerous human exposures resulting from the husbandry
practices there. Keep in mind that in
poultry are frequently sold live to the consumer who must butcher and
prepare the bird themselves.
Since 1997, more than
16 outbreaks of H5 and H7 influenza have occurred in poultry within the
. The virus strains in each of these outbreaks were just as likely as
H5N1 to become human influenza viruses, yet none of them made the jump
from avian virus to human virus. Of all the people exposed to the avian
flu during these 16 outbreaks, according to the CDC (http://www.cdc.gov/flu/avian/),
only 2 mild cases of human infection in the
Despite the media
attention to Bird Flu, there is no increased risk of catching the flu
from exposure to birds, other than poultry in
. There have been no documented cases of humans catching Avian Flu from
pet birds such as parrots, finches and other commonly kept species (http://www.cdc.gov/flu/avian/gen-info/avian-flu-humans.htm).
All birds imported into
have been routinely tested for pathogenic Avian Influenza since 1974. Of
the many millions of birds imported during this 30 year period,
pathogenic Avian Influenza was only found in 1 shipment of birds from
. Exotic birds being legally imported into the
represent virtually NO risk of introducing pathogenic Avian
Influenza virus as they are ALL tested during quarantine.
being bred for sale in the
represent virtually NO risk for Pathogenic Avian Influenza unless
they are co-mingled with infected poultry and at this time pathogenic
Avian Influenza (H5 or H7 strains) are not known to exist in the
. USDA is continually monitoring for the presence of Influenza and
New Castles Disease in domestic "backyard" and commercial
It is important to
understand that Bird Flu or Avian Influenza is a disease of birds
(mostly poultry), and it is not readily transmitted to humans. For many
millennia, Avian Influenza has existed in
. It is found in migrating waterfowl on an annual basis. H5N1 is no more
likely to infect humans than the Avian Flu strains that arrive every
year yet do not infect humans.
H5N1 gains the ability for human to human transmission, it will be humans
spreading the disease to humans, not bird to human transmission.
A human version of the virus will most likely enter the
by infected persons arriving from outside the
on airplanes. The virus will not arrive by
imported birds which are quarantined, and not by migrating birds. And
example of this type of disease transmission was the spread of SARS into
. This disease introduction was quickly
recognized and brought under control due to vigilance of medical and
fear of contracting bird flu from pet, companion, or zoo birds in the
is totally unfounded. The chance of
contracting bird flu from native birds is also extremely remote.
Attention needs to be appropriately placed on surveillance of incoming
international travelers if and when the virus shifts sufficiently to
maintain virulent human to human transmission.
posting authorized and encouraged by NAWA
Flu Prevention & Protection Through Bio-security Measures
by the National Avian Welfare
Bird Flu Carriers: Wild migratory waterfowl, ducks and geese, are the
primary carriers of a variety of strains of bird flu viruses, including
the H5N1 subtype which can be dangerous to humans. New strains of H5
and/or H7 bird flu viruses have always arrived every year. H5N1 is not
H5N1, is rarely transmissible from infected poultry to humans. Only
people who have contact with
H5N1 infected poultry, their feces,
or water contaminated by their droppings may become infected.
H5N1, is NOT transmissible from human to human at this time, but it is
feared that H5N1 might mutate into a form that is transmissible from
human to human. If H5N1 becomes transmissible from human to human, birds
will no longer be a source of infection.
Standard biosecurity measures can protect your birds from infection by
various diseases including the H5N1 virus. The following simple measures
can be taken to protect your birds from exposure to H5N1 and other
1. If your birds are housed inside a building or your home, and you have
no poultry at your home and you do not have any free roaming poultry
with access to your facilities, your birds will have no opportunity to
contract the disease. If you handle other birds away from home or visit
an area with free-roaming waterfowl, it is recommended to shower, change
clothing and disinfect shoes before handling your birds.
2. If you do not visit or frequent feed stores or other sites frequented
by individuals or farmers with free ranging chickens, or other poultry,
you should have no opportunity to pick up viral particles on your shoes
to track into your home or facility.
3. If you have a small flock of poultry that is contained in a building
or a securely fenced area with wire enclosing the top portion so that
wild birds cannot enter, your poultry will be protected from exposure to
bird flu from wild birds. However, if you DO have any poultry located at
your facility, it is recommended that you routinely wear special
footwear outside when feeding the poultry, and remove that footwear
prior to entering your house or exotic bird facility.
4. If you have a neighbour with free ranging poultry, especially if they
have a pond which is visited by wild waterfowl during migration, it is
recommended that you put in place a security fence so that the free
ranging poultry cannot enter your property.
5. If you have a pond on your property which provides access to wild
waterfowl, and you have a flock of ducks or geese or swans, it is
recommended that you corral the domestic or exotic waterfowl so that
they cannot access the pond and contact the wild migratory waterfowl or
6. If you have family or friends who own poultry or waterfowl, it is
recommended that you have them remove their footwear prior to entering
your home or bird facility.
7. If you are feeding wild songbirds at bird feeders, it is unlikely
that you will come into contact with a bird carrying bird flu. However,
it is wise to wash your hands well after handling and refilling the
8. If you find a dead wild bird near your birds, wear disposable gloves
to pick it up. Take it to a vet or state lab for necropsy and testing.