Transcript Anthrax - Georgia FFA

Anthrax
A Special Lesson
Produced by: Amber Dowd & Dr. Frank B. Flanders
Georgia Agricultural Education Curriculum Office
November 2001
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Anthrax is no stranger to agriculture
Anthrax has been on America’s mind
recently because of terrorist attacks,
however, anthrax has affected
humans and animals for centuries.
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Anthrax is rare on the East
Coast. Farmers in the West,
Midwest and parts of the
South still deal routinely
with anthrax.
Animal deaths from
anthrax rarely make news.
Deaths of wild animals
such as deer and bison as
well as domesticated
animals is common.
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The last documented case of anthrax
in Georgia animals was in 1948. The
environment in Georgia, and some
other states, does not seem to be
suitable for long-term survival of
anthrax. The characteristics of
Georgia soils (low pH and not as hot
and dry as soils in the Western US)
are thought to be a poor
environment for anthrax spores.
Texas is one state in which anthrax is
common. More than 1600 cattle died
in Texas from anthrax during 2001.
What is Anthrax?
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A disease of most mammals, including humans,
that is caused by a rod-shaped, spore-forming
bacterium called Bacillus anthracis.
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Disease is defined as any
deviation in the normal
health of plants or animals.
Microorganisms that most
commonly cause disease are
bacteria, viruses and fungi.
Anthrax was the first
microorganism ever linked
specifically to a disease.
History of Anthrax
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Although anthrax has recently become a greater threat
to humans, it is suspected to have been around since
biblical times.
The 5th and 6th plagues in the Bible’s book of Exodus
may have been anthrax.
The “Black Bane,” a disease that that swept Europe in
the 1600’s, was most likely anthrax.
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In the 1870’s, Robert Koch, a
German family doctor,
accidentally discovered anthrax
while trying to figure out the
cause of death in an animal.
In 1876, he published a paper
identifying the bacterium,
genus and species bacillus
anthracis, as the cause of
anthrax.
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In 1881, Louis Pasteur made anthrax the
first bacterial disease for which a vaccine
was available.
More than 6,000 cases in humans occurred
in Zimbabwe between October 1979 and
March 1980.
Anthrax Worldwide
Military personnel deployed to areas with high risk
for exposure are usually vaccinated.
Susceptibility
All mammals appear to be susceptible to
anthrax, but ruminants such as cattle,
sheep, and goats are the most susceptible,
followed by horses and swine.
Anthrax is a zoonotic disease, meaning it may
spread from animals to humans. Examples of
other zoonotic disease are, cat-scratch fever, rabies
and ringworm.
However, it does not spread from human to human.
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Anthrax spores occur in many areas, such as soil,
but only become a problem when ingested in a
sufficiently large concentration.
Grazing animals may be
more susceptible because
they breath air close to
the ground as they graze
where anthrax spores are
in greatest concentration.
 “Anthrax zones” are areas where
there is a high concentration of
anthrax spores in the soil.
 Anthrax zones in the US are
primarily where the cattle drive
trails of the 1800’s took place.
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Spores can survive for many
decades and are resistant to
heat, sunlight, and drought.
Anthrax in Animals
How is Anthrax Contracted?
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Animals are usually infected by ingesting soilborne spores, such as in contaminated food
or water.
Spores can be picked up directly from the soil
or plants through grazing or from feed grown
on infected soil.
It is possible for animals to become infected
by inhaling dust containing anthrax spores.
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Bites from flies and other insects that carry
anthrax have also been reported to cause
infection.
The incubation period of natural infection in
animals is usually 3 to 7 days, with a range of
1 to 14 days.
Symptoms in Animals
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Signs are fever up to 107º F, muscle tremors,
respiratory distress, and convulsions. Death
occurs quickly and often before symptoms are
observed.
Animals that die of anthrax bloat quickly.
Blood may come from the nose and other
body openings.
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Animals that die of anthrax don't have
rigor mortis (stiffening of the body
after death) because the blood does
not clot upon death.
A toxin released by the bacteria
prevents blood clotting in the bodies of
animals that die of anthrax.
 Swine, dogs, and cats usually have swelling
of the neck. Carnivores apparently have
some natural resistance to anthrax and
recovery is not uncommon.
 If a problem is suspected a vet should be
called as soon as possible.
Preventing Infection
 If anthrax is diagnosed, all the animals in contact
must be examined for up to two weeks, and their
temperatures need to be taken regularly.
 If an animal is found to have a fever, it should be
given antibiotics immediately.
 When animals are at risk of anthrax they should be
vaccinated annually.
 The anthrax vaccine has proven to be effective in
field situations and can protect animals for about
one year.
Treatment of Infected
Animals
 Because of the rapid course of the disease,
infected animals are often found dead or too
sick to be treated.
 Anthrax can be treated if it is still in the early
stages when fever is the only clinical sign.
 The treatment for anthrax is to use antibiotics
for at least five to six days.
Disposing of Infected Animals
One reason for the low human rate of infection may be
that most ranchers recognize the signs of anthrax in
animals, know how to avoid exposure and to dispose of
dead animals.
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Contact with infected blood or
tissue should be avoided by
wearing gloves.
Wash-up after contact with an
infected animal is imperative.
Burying infected animals only
preserves the organism deep
within the soil and is not
recommended.
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Animals that die of anthrax should be
burned on-site in a very hot fire. Dragging
them to another area only spreads the
disease.
Anthrax in Humans
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The disease occurs when spores enter
the body, germinate, multiply, and
release toxins.
In humans, anthrax is fairly rare; the
risk of infection is about 1/100,000.
Exposure to the bacteria causes the
body to produce antibodies for the
disease.
Most exposure is from working with
infected animals.
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Human anthrax has three major clinical
forms:
 cutaneous
 inhalation
 gastrointestinal
If left untreated, anthrax in all forms
can lead to septicemia and death.
Cutaneous (Skin) Anthrax is the most common.
It is contracted through a cut or abrasion on the skin.
 Inhalation anthrax
is the most deadly,
resulting in death
95-100% of the
time.
 An estimated 8 to
10 thousand spores
must be inhaled to
contract the
disease.
A deadly but far less common form of anthrax
in humans is gastrointestinal anthrax,
contracted from eating undercooked, infected
meat.
 It is fatal 20-60% of the time without
treatment, but is very rare, because
animals usually die within 12 to 48 hours
after contracting anthrax.
 Farmers generally know not to butcher and
eat animals that die of unknown causes.
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The last case of inhalation anthrax in the
United States before 2001 was in 1976 in
California.
The last case of cutaneous anthrax before
2001 occurred in North Dakota in 2000.
Am I at risk?
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The average person has a very small chance of
being exposed to anthrax, however, everyone
should be extremely watchful and careful,
especially around sick animals.
USDA inspections of commercially processed
meat keeps our food supply safe.
A person can be exposed without having the
disease.
Symptoms in Humans
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Fever (greater than 100° F)
Flu-like symptoms (most common)
Cough, chest discomfort, shortness of breath, fatigue,
muscle aches
Sore throat, difficulty swallowing, enlarged lymph
nodes, headache, nausea, loss of appetite, abdominal
distress, vomiting, or diarrhea
A sore on the face, arms or hands, that starts as a
raised bump and develops into a painless ulcer with a
black area in the center
Diagnosis and Treatment
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Anthrax can be diagnosed by testing for
antibodies or bacteria in blood.
Antibiotics, such as Cipro, are used to treat
anthrax.
Anthrax as a Weapon
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To some military planners, anthrax is the
single greatest biological warfare threat.
Even though there are world treaties against
using biological and chemical weapons, it is
suspected that countries are still producing
them.
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The first attempt to use anthrax
as a biological warfare agent
occurred in World War I, when
Norwegian police arrested a
German agent carrying two vials
of the bacteria to be used to
infect reindeer ferrying supplies
to allied forces in Europe. The
spores were still viable when
scientists analyzed them in
1998.
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In World War I almost every country involved
had a biological warfare program that included
anthrax.
During World War II, Britain experimented
with anthrax as a biological warfare agent on a
British island.
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After the war, the island was burned to
decontaminate it. However, after burning, the
concentration of anthrax was the same as before it
was burned. Britain needed 36 years to clean up
the island.
Anthrax is considered a viable biological
weapon because:
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it produces spores that are hard to kill
and that last for decades.
it kills quickly.
it can be ground to a fine powder that
can be suspended in the air.
it is easy and cheap to produce.
it has a potential for mass destruction.
Anthrax in the Mail
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In 2001, terrorists began sending
anthrax through the mail.
In some instances, anthrax
exposures have occurred with
several persons becoming infected,
and some have died.
To prevent exposure everyone
should learn how to recognize a
suspicious package or envelope.
Summary
Anthrax:
 has been around since biblical times
 is a disease agricultural producers have always had
to deal with
 can be used as a deadly biological weapon
 is common along the cattle trails of the west
 is caused by a bacteria
 is a manageable disease unless spread maliciously