1. 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’.

2. 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.

3. Anthrax is rare on the East Coast
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.
Before October 2001, the last cases of anthrax, all cutaneous, were  Florida,  South Carolina,  North Carolina, 1987
In the United States there are recognized areas of infection in South Dakota, Nebraska, Arkansas, Texas, Louisiana, Mississippi and California; small areas exist in other states.

4. The last documented case of anthrax in Georgia animals was in 1948
The last documented case of anthrax in Georgia animals was in 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.

5. What is Anthrax?
A disease of most mammals, including humans, that is caused by a rod-shaped, spore-forming bacterium called Bacillus anthracis.

6. 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.

7. 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 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.

8. 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.

9. 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.

10. Anthrax Worldwide
Red – Epidemic Lt. Green-Probably free
Pink – Endemic Dk. Green – Free
Yellow – Sporadic Gray - Unknown
Military personnel deployed to areas with high risk for exposure are usually vaccinated.

11. 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.

12. However, it does not spread from human to human.
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.
Health officials suggest wearing gloves to prevent contact with zoonotic diseases.
However, it does not spread from human to human.

13. 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.

14. “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.
Spores can survive for many decades and are resistant to heat, sunlight, and drought.

15. Anthrax in Animals

16. 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.

17. 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.

18. 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.

19. 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.

20. Swine, dogs, and cats usually have swelling of the neck
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.

21. 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.

22. 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.  

23. 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.
“Another reason for the low human rate of infection in the wild may be that most ranchers recognize the signs of anthrax in animals. “
“It's usually fairly obvious when you know what to look for," said Martin Hugh-Jones, a veterinarian at Louisiana State University who monitors anthrax. "[Animal victims] bloat up fairly quickly. … You get blood coming out of the nose and anus in some cases and they don't have rigor mortis."
“When ranchers see the signs, most know to avoid infected blood or tissue, to wash up after animal contact and to use other techniques to avoid infection, experts say.”
"Rather than fooling with the animal carcasses, it's highly recommended that they burn that animal on site rather than dragging it from one area to another," said Terry Conger, a veterinarian who is Texas' state epidemiologist for animal cases. "If they bury the animal, that will only preserve the organism deep within the soil."
Source – ABC News

24. 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.

25. Animals that die of anthrax should be burned on-site in a very hot fire. Dragging them to another area only spreads the disease.

26. 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.
Symptoms of disease vary depending on how the disease was contracted, but symptoms usually occur within 7 days.
Cutaneous anthrax is the most common naturally occurring type of infection (>95%) and usually occurs after skin contact with contaminated meat, wool, hides, or leather from infected animals. The incubation period ranges from 1-12 days. The skin infection begins as a small papule, progresses to a vesicle in 1-2 days followed by a necrotic ulcer. The lesion is usually painless, but patients also may have fever, malaise, headache, and regional lymphadenopathy. Most (about 95%) anthrax infections occur when the bacterium enters a cut of abrasion on the skin. Skin infection begins as a raised bump that resembles a spider bite, but (within 1-2 days) it develops into a vesicle and then a painless ulcer, usually 1-3 cm in diameter, with a characteristic black necrotic (dying) area in the center. Lymph glands in the adjacent area may swell. About 20% of untreated cases of cutaneous anthrax will result in death. Deaths are rare if patients are given appropriate antimicrobial therapy.
Inhalational anthrax is the most lethal form of anthrax. Anthrax spores must be aerosolized in order to cause inhalational anthrax. Studies show that 4,000 – 5,000 spores must be present to cause an infection. The incubation period of inhalational anthrax among humans is unclear, but it is reported to range from 1 to 7 days, possibly ranging up to 60 days. It resembles a viral respiratory illness and initial symptoms include sore throat, mild fever, muscle aches and malaise. These symptoms may progress to respiratory failure and shock with meningitis frequently developing.
Gastrointestinal anthrax usually follows the consumption of raw or undercooked contaminated meat and has an incubation period of 1-7 days. It is associated with severe abdominal distress followed by fever and signs of septicemia. The disease can take an oropharyngeal or abdominal form. Involvement of the pharynx is usually characterized by lesions at the base of the tongue, sore throat, dysphagia, fever, and regional lymphadenopathy. Lower bowel inflammation usually causes nausea, loss of appetite, vomiting and fever, followed by abdominal pain, vomiting blood, and bloody diarrhea.

27. Human anthrax has three major clinical forms:
cutaneous
inhalation
gastrointestinal
If left untreated, anthrax in all forms can lead to septicemia and death.

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

29. 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.

30. 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.

31. 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.
In a case in the summer of 2001 in western Texas, a man contracted the skin form of anthrax, apparently after attempting to skin a bison that had died of the disease, state health officials said. He was treated with antibiotics.
In the North Dakota case, a man successfully was treated with antibiotics after handling five cows he believed died of anthrax.

32. 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.

33. 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

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

35. 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.

36. 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.

37. 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.

38. 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.

39. 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.
Some characteristics of suspicious packages and envelopes include the following:
 Inappropriate or unusual labeling    - Excessive postage    - Handwritten or poorly typed addresses    - Misspellings of common words    - Strange return address or no return address    - Incorrect titles or title without a name    - Not addressed to a specific person    - Marked with restrictions, such as “Personal,” “Confidential,” or “Do not x-ray”    - Marked with any threatening language    - Postmarked from a city or state that does not match the return address
Appearance    - Powdery substance felt through or appearing on the package or envelope    - Oily stains, discolorations, or odor    - Lopsided or uneven envelope    - Excessive packaging material such as masking tape, string, etc.
If a package or envelope appears suspicious, DO NOT OPEN IT.

40. 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