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Facts About...


What is it?

Anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis. It is primarily a disease of sheep, goats, cattle and swine. Animals shed the bacteria, and on exposure to air, the microbes form spores that can survive in the environment for a long time. The spores can remain in soil for many years. Anthrax can also occur in humans when exposed to infected animals or tissue from infected animals. In humans the disease usually affects the skin (cutaneous anthrax). It may however infect the nasal passages (inhalation anthrax) and the intestines.

Anthrax is a reportable disease and must be reported immediately to the Health Department.

How is it spread?

Anthrax cannot be transmitted from person to person. Skin anthrax infection is spread by exposure to animals dying of the disease, especially wool, hides or other products made from the animal. Inhalation anthrax is caused by inhaling anthrax spores. Exposure to the spores may be through contact with infected animals or spread intentionally as an agent of biological warfare. Similar exposures may occur with intestinal anthrax. The time from infection to the development of symptoms is usually 1-7 days, although up to 60 days is possible. Articles and soil contaminated with anthrax spores may be infectious for decades.

What do I look for?

Skin: Most (~95%) anthrax skin infections occur when the bacteria enter a cut or abrasion. Symptoms begin with a raised itchy bump that looks like an insect bite. In 1-2 days, the bump develops into a small blister, and then into a painless ulcer, usually 1-3 cm in diameter. The ulcer has a blackened centre. Nearby lymph glands may swell. Death from skin anthrax infection can occur in untreated cases so treatment with appropriate antibiotics is required.

Inhalation: Initial symptoms are similar to a common cold, and then progress to severe breathing problems and shock. Chest x-rays often show specific changes. Treatment with appropriate antibiotics should be given as soon as possible. Even with treatment, the death rate from inhalation of anthrax is high.

Intestinal: This form of anthrax is rare and difficult to recognize. Symptoms include stomach pains, fever, sepsis, and severe diarrhea. Given the difficulty of early diagnosis, this form of anthrax can lead to death in a number of cases.

How can I get tested?

Routine testing for anthrax is not recommended. Testing should only occur when a diagnosis of anthrax is suspected and/or as part of an investigation. Specimens can be submitted to the laboratory that normally provides bacteriological testing. If necessary, further testing can be arranged through specialized laboratory testing.

How is it treated?

Skin: Penicillin is the drug of choice for skin anthrax and is given for 5-7 days. Other antibiotics are also effective.

Inhalation/Intestinal: Treatment started after people are severely ill may not be effective. Therefore, treatment should begin at the earliest signs of disease with intravenous antibiotic therapy under the care of an infectious disease specialist. Intensive care therapy is often needed.

Are there vaccines available to prevent it?

Anthrax vaccine is not licensed in Canada and is not available commercially. There is no need, however, to vaccinate the general public or people who have not been exposed to anthrax. Health Canada does stockpile a quantity of anthrax vaccine for specific uses. Should a significant event occur, and in consultation with public health officials, anthrax vaccine could be accessed through the Special Access Program at Health Canada.

How can I protect myself?

If you think you could have been exposed to anthrax, remove yourself from the exposure and immediately wash with soap and water. Call 911 if there is a concern that you may have been exposed. Confirmed exposures to anthrax are treated with antibiotics (e.g., ciprofloxacin, doxycycline or amoxicillin) and should be started as soon as possible. Unless anthrax has been confirmed in the area, persons potentially exposed should await laboratory results prior to being placed on preventative treatment. Should an exposure to anthrax be confirmed, antibiotics should be taken for at least 60 days since exposure.

More information can be obtained from

Durham Region Health Department, Environmental Help Line 905-723-3818 or 1-888-777-9613

April 22, 2013