Kelsey Morgan
Dr. Hulet
An Sc 311
December 14, 2012
Avian Influenza
Avian influenza is a virus that is introduced into a flock by wild birds, which are
the virus’s natural host. It is spread to domesticated ducks, chickens and turkeys. From
there it spreads rapidly from bird to bird. It can be spread by saliva, nasal secretions or
feces. The virus can be spread through direct bird to bird contact by one of these body
fluid or by one of the fluids being left on a surface by an infected bird and then a healthy
bird coming in contact with it.
Who can be infected with this virus? We know that birds are infected but there a
few other species that can be infected. These include humans, pigs, tigers, leopards,
ferrets, domestic cats, dogs, stone-marten, and civet cats.
Humans who contract the virus usually do so because they are in close contact
with birds that are infected. They also were not using proper sanitation techniques.
With humans the virus is not contagious, so no need to worry about catching the bird flu
from a friend.
There are two forms of the virus. The low pathogenic form has mild symptoms.
These include a decrease in egg production and ruffled feathers. The other from is the
highly pathogenic which is very contagious. The mortality rate is 90 to 100% and
reaches this point within 48 hours of the virus first being detected. This mortality is
significantly high because the birds have to be euthanized immediately to eradicate the
virus before it spreads. The sooner the birds are destroyed the smaller the chance is for
spreading. It also affects many of the main organs.
There are a few different types of the avian influenza that are infecting our world.
Type A has a few subtypes: H5, H7, and H9. Each of these subtypes has nine potential
subtypes of their own. Type A influenza is the form that infects birds and causes such
devastation to the poultry industry. Influenza Type B is only found in humans and
fortunately has only caused epidemics. Another form found only in humans is Influenza
Type C; this is a mild form that does not cause much harm. Many new strains of
Influenza type A and B are forming constantly. The new strains replace old ones and
become more virulent with each generation.
Some signs and symptoms of avian influenza are: ruffled feather, soft-shelled
eggs, depression and droopiness, sudden drop in egg production, loss of appetite, cyanosis
of the wattles and comb, edema and swelling of the head, eyelids, comb, wattles, and
hocks, diarrhea, blood-tinged discharge from nostrils, loss of ability to walk and stand,
pin-point hemorrhages, and respiratory distress. No vaccine, antibiotic, or treatment
can be administered to birds to prevent, kill or help the treatment of Avian Influenza.
The only option is the elimination of the birds. There are vaccines that can be given to
lower the chance of chickens becoming infected but it does not have a very high
percentage of lowering this risk.
The last major breakout in the United States happened in Lebanon and Lancaster
counties in 1996-1997. Nine flocks had to be depopulated and a 75 square mile area was
put under quarantine by the Pennsylvania Agricultural Department. Back just a few
years ago a flock in Lancaster County was tested positive for the Avian Influenza but it
was quickly taken under control before the virus could spread farther. The most recent
outbreak was this June in Mexico. 200,000 birds died from the avian influenza and an
additional 60,000 had to be destroyed. The amount of birds lost was so large because
this outbreak occurred in an area that is densely populated with poultry growers and
breeders. In July of this year an Indonesian man was tested positive for H5N1, the most
harmful strain of the virus, and died two weeks later.
Many of the outbreaks that occur are happening in foreign countries where
sanitation and biosecurity are not as well developed as it is in the United States. This is
why I propose that a limited amount of international poultry is imported into the
country. When birds are imported they need to kept on a quarantine to ensure that they
are not carrying the avian influenza, or any other harmful disease for that matter. When
bringing in new birds to a flock the new birds should be kept isolated from the existing
for a period of time to ensure that they are not diseased; this includes small backyard
flocks too. Flocks should also be kept away from having any contact with wild birds. For
producers that have commercial flocks this will be an easy task to accomplish. For
producers that are raising organic, free range or backyard chickens this will be more
difficult. In instances like myself where I have a small flock with a fenced in yard that is
small enough to be covered with netting, this can be accomplished to limit the amount
of wild bird to chicken contact. For the organic and free range producers this will not be
feasible for they have such a large area to cover. The best option for these farmers is to
keep the feed and watering containers enclosed in some sort of small shelter that
prohibits wild birds from hanging out in the area. Another proposal is if a flock is tested
positive for avian influenza the entire flock should be depopulated immediately to limit
the chances of spreading the virus. The entire facilities and equipment need to be
sanitized and cleaned properly. My final proposal is biosecurity; it is the most
important precaution/ action to be taken to reduce the chances of avian influenza being
introduced into a flock. Such things are booties, hairnets, overalls, and foot dips are
important protective clothing to limit the spread of disease between poultry houses.
Another crucial part is to not allow people who have been on another poultry farm to
enter onto your farm without proper cleansing of their selves and the vehicle that they
had on their property.
In conclusion avian influenza is a very contagious virus that has no cure or
vaccine to prevent. It is detrimental to the poultry industry and the best way to prevent
it from occurring in your flock is biosecurity.
References
Avain Influenza - situation in Indonesia - update [Internet]. [place unknown]: World Health
Organization; c2012 [cited 2012 Nov 6]. Available from:
http://www.who.int/csr/don/2012_08_10b/en/index.html
Avain Influenza: Outbreaks [Internet]. [place unknown]: Agriculture Department - Animal
Production and Health Divsion; c2012 [cited 2012 Nov 8]. Available from:
http://www.fao.org/avianflu/en/maps.html
Avian Influenza outbreak in Mexico. Farmer's Weekly [Internet]. 2012 Jun 27 [cited 2012 Nov
9]; [6 paragraphs]. Available from:
http://www.fwi.co.uk/Articles/27/06/2012/133628/Avian-Influenza-outbreak-inMexico.htm
Centers for Disease Control and and Prevention [Internet]. Altlanta (GA): Centers for Disease
Control and Prevention; c2012 [cited 2012 Nov 5]. Available from:
http://www.cdc.gov/flu/avianflu/
Highly pathogenic avian influenza, Nepal [Internet]. [place unknown]: World Organisation for
Animal Health; c2012 [cited 2012 Nov 6]. Available from:
http://www.oie.int/wahis_2/public/wahid.php/Reviewreport/Review?page_refer=MapFull
EventReport&reportid=12529
Influenza Viruses [Internet]. Altlanta (GA): Centers for Disease Control and Prevention; c2012
[updated 2005 Nov 18; cited 2012 Dec 10]. Available from:
http://www.cdc.gov/flu/avian/gen-info/flu-viruses.htm
Jacob JP, Butcher GD, Mather FB, Miles RD. Avian Influenza in Poultry [Internet]. [place
unknown]: University of Florida; [cited 2012 Nov 5]. Available from:
http://edis.ifas.ufl.edu/pdffiles/PS/PS03200.pdf