Anthrax

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Anthrax

• A Special Lesson
• Produced by Amber Dowd Dr. Frank B. Flanders
• Georgia Agricultural Education Curriculum Office
• November 2001
• Teachers should view notes pages for additional
  information on certain slides.
• View note pages by clicking on View and then
  Notes Page.

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Anthrax is no stranger to agriculture
Anthrax has been on Americas 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.

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What is Anthrax?

• 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.

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History of Anthrax

• 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 Bibles book of
  Exodus may have been anthrax.
• The Black Bane, a disease that that swept
  Europe in the 1600s, was most likely anthrax.

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• In the 1870s, 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.

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Anthrax Worldwide
Military personnel deployed to areas with high
risk for exposure are usually vaccinated.
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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.
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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.

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• 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 1800s took place.
• Spores can survive for many decades and are
  resistant to heat, sunlight, and drought.

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Anthrax in Animals
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How is Anthrax Contracted?

• Animals are usually infected by ingesting
  soil-borne 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.

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Symptoms in Animals

• 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.

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• 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.

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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.

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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.  

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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.

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Anthrax in Humans

• 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.

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Cutaneous (Skin) Anthrax is the most common.
It is contracted through a cut or abrasion on the
skin.
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• 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.

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• 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.

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Am I at risk?

• 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.

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Symptoms in Humans

• 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

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Diagnosis and Treatment

• Anthrax can be diagnosed by testing for
  antibodies or bacteria in blood.
• Antibiotics, such as Cipro, are used to treat
  anthrax.

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Anthrax as a Weapon

• 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.
• 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.

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• Anthrax is considered a viable biological weapon
  because
• 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.

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Anthrax in the Mail

• 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.

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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

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