Anthrax is caused by infection with Bacillus anthracis which is a gram-positive spore-forming rod type of bacteria. In its spore form, the bacteria can survive for decades in the environment during adverse conditions and is easily aerosolized. Certain environmental conditions produce "anthrax zones" where the soil is heavily contaminated with anthrax spores. These conditions include soil rich in organic material and dramatic changes in climate. It is an important veterinary disease especially in domestic herbivores (cows, sheep, cats, dogs, rabbits, etc.) which come into contact with the contaminated soil. Aside from contracting the disease from the soil, herbivores can also become infected from the bites of certain flies. In the United States, these "anthrax zones" closely parallel the cattle drive trails of the 1800s.
There are three forms of anthrax. The first is the cutaneous form which is contracted by close contact of abraded skin with products derived from infected herbivores, namely sheep, cattle and goats. The symptoms are readily recognizable and successful treatment with any number of antibiotics makes the cutaneous form rarely fatal. While uncommon in the United States with the last reported case in 1992, the cutaneous form remains especially common in parts of Asia and sub-Saharian Africa.
A second type of anthrax is acquired through the gastrointestinal route by the consumption of contaminated meat. Gastrointestinal anthrax is exceedingly rare.
The form most likely to be employed by biological terrorists is inhalation anthrax. In its naturally-occurring state, it has been an occupational hazard of those working in slaughterhouses and textile factories. Immunization of these workers has all but eliminated this hazard in Western nations. Caused by the spore form of anthrax, inhalation anthrax generally occurs 1 to 6 days after infection. A nonspecific flu-like illness is the first sign of infection which is characterized by fever, headache, cough and mild chest discomfort. These initial qualities make it difficult to differentiate from the common flu. After the flu-like symptoms subside, a brief 1 to 3 day period of improvement occurs but then rapid deterioration follows. Death is universal in untreated cases and if the initial flu-like symptoms are not caught within 48 hours, 95% of treated cases are fatal. However, anthrax has little potential for person-to-person transmission which allows health-care workers to treat those infected. The relatively short incubation period, the rapid progression of disease, the non-descript initial symptoms and its high rate of fatality make anthrax a potent tool for biological terrorists.
So... yeah, you could probably get it from eating it too... but if that's the case here, then it was a freak accident. Bioterrorists only use aerial Anthrax. Anything else would just be a waste of their time.
