INDEPTH: BIOLOGICAL WEAPONS|
CBC News Online | February 18, 2004
Anthrax is a disease caused by a bacterial infection, most often affecting large herbivores such as cattle, sheep or bison, either wild or domesticated.
It is most common in developing countries in Central and South America, Eastern and Southern Europe, Africa, Asia, the Caribbean and the Middle East.
People most often catch the disease through contact with infected animals or their wool or hides. The bacteria can enter through cuts or scrapes in the skin. This cutaneous form of anthrax causes ulcers and coal-black scabs, which give anthrax its name: anthracis is the Greek word for coal.
Anthrax can also be transmitted to people by eating contaminated meat. Intestinal anthrax causes intense pain, bleeding and diarrhea.
The anthrax bacteria, Bacillus anthracis, can also form spores and be transmitted through the air. The inhaled form of anthrax, also called woolsorters' disease, is much more severe than the cutaneous form and is usually fatal.
This is the form that killed a photo editor at the office of a supermarket tabloid in Boca Raton, Florida in October.
The symptoms of inhalation anthrax are flu-like at first: aches, pains, fever, fatigue. After a few days, symptoms progress to severe breathing problems and shock, a reaction to the anthrax toxin in the blood.
In any of its forms, anthrax can not usually be transmitted from one person to another. Anthrax can be treated with antibiotics if it's caught early. But by the time the symptoms of anthrax become evident, it's usually too late to treat.
Although the inhaled form of anthrax is often cited as a potential biological weapon, there are limitations to its use.
The bacteria is found in nature, but it is difficult to find strains that will cause serious disease. And once such a strain is found, it's dangerous to handle.
The spores of anthrax would have to be ground down to a size that can be inhaled easily, freeze dried and delivered in an aerosol spray from an aircraft.
A standard crop-dusting airplane, however, would not be suitable. The spraying equipment used to deliver insecticide onto fields produces droplets that are too large to be absorbed through the lungs.
Even after it's delivered, the bacteria's behaviour is somewhat unpredictable. It normally has an incubation period of up to seven days, but could take up to 60 days to develop.
And unlike other potential biological weapons, such as smallpox or plague, anthrax can't be transmitted from person to person, so it won't spread through a population after it's released.
However, if someone was determined enough to release anthrax in this way and weather conditions were perfect for such an attack, it could be devastating.
A U.S. Congress analysis estimated that 100 kilograms of anthrax spores released over Washington, D.C. would cause between 130,000 and 3 million deaths, as lethal as a hydrogen bomb.
The largest release of anthrax spores was an accidental one. In Sverdlovsk, Russia in April 1979, 68 people died after a small amount of anthrax powder was released through the ventilation system of a near-by secret military base.
Although a vaccine for anthrax exists, it is used almost exclusively on American military personnel. People who work with the bacteria in laboratories and people who handle furs, hides and other products from overseas are also vaccinated.