Anthrax

Anthrax, known as Bacillus anthracis is a Gram-positive, rod-shaped bacterium that is well known for its use in past bioterrorism attacks, although it is naturally found in the soil.

Anthrax is classified as a Hazard group 3 pathogen due to its ability to cause disease and potential to spread to the community. If left untreated, all types of anthrax can cause death. However, effective prophylaxis or treatments are usually available.

Anthrax has been used as a bioweapon for its ability to form spores that are highly resistant to heat, drying and common disinfectants such as 95% ethanol: the common disinfectant of a Biosafety level II lab.

Figure: Gram stain of Bacillus anthracis.

Anthrax spreads indirectly, via its spores, which can be picked up from the ground by grazing animals. As a weapon, the spores are easily transported and can spread through direct contact, and they are also light enough to spread through the air.

Bacillus anthracis can produce toxins that are very toxic to the human body, causing severe human disease and ultimately death. Additionally, the presence of a polyglutamic capsule, makes it more difficult for the immune system to fight it. Luckily, anthrax is very rarely transmitted from person to person.