Bacillus anthracis is an encapsulated spore-forming bacterium. The bacterium is a gram positive, non-motile aerobe. It is also rod shaped occurring in chains and about 1-1.5 micrometers in diameter and 3-10 micrometers in length. The rods have an oval spore in the center, which is resistant to both chemical disinfectants and heat, although it can be destroyed with autoclaving for 15 minutes. It has no good function but does cause an acute infection disease called anthrax.
Anthrax occurs mostly in developing countries such as South America, Europe, Asia, Africa, and the Middle East. The spores can live in the soil for many years, infecting animals when they eat what grows in the soil. Infection of animals, most commonly cattle, sheep, and goats, is usually fatal. The processed hides and skins of the infected animals can also harbor spores for many years. Anthrax is a zoonotic disease, meaning that it can spread from animals to humans. There is no evidence of direct spread from person to person and is extremely unlikely to occur.
There are three forms of infection in humans. The first one is cutaneous, which happens through the handling of infected products, like wool, hides, leather or hair products (especially goat hair). The bacterium enters through a cut or abrasion on the skin. It begins as a itchy bump that resembles an insect bite but then develops into a vesicle and then to a painless ulcer. The black area in the center is dying skin. This accounts for about 95% of the anthrax infections and about 5-20% of untreated cases will result in death.
The second form is very rare but is more fatal than the others. Inhalation is caused by breathing in airborne spores from the infected products or from working with the soil. It is most deadly because it resembles a common cold or flu, going undetected until is it too late. The symptoms progress to severe breathing problems and eventually shock. About 70-80% of untreated cases result in death.
Gastrointestinal, the third form, is also rare. It occurs by consumption of undercooked, contaminated meat and causes nausea, loss of appetite, vomiting and fever followed by abdominal pain and vomiting of blood. About 25-75% of untreated cases result in death. This may also cause explosive outbreaks. The symptoms of anthrax do not show up until 2-7 days after contact, making it almost impossible to track.
Recovery from an anthrax infection can result in prolonged immunity. Treatment can be done with antibiotics, like penicillin, tetracycline, erythromycin, and chloramphenicol. If treatment is done early enough, most infections can be healed. If treatment is done too late, it usually proves fatal. Prevention can be done by a cell-free filtrate vaccine, meaning that no live or dead bacteria are used in the preparation of the vaccination, and is manufactured and distributed by BioPort, Co in Lansing, Michigan.
Center for Disease Control - http://www.cdc.gov/ncidod/dbmd/diseaseinfo/anthrax_g.htm
US Dept of Agriculture - http://www.aphis.usda.gov/oa/pubs/anthrax.html
Food and Drug Administration - http://www.fda.gov/cber/vaccine/anthrax.htm
State Govt of Victoria, Australia - http://www.health.vic.gov.au/ideas/bluebook/anthrax.htm
*Disclaimer - This report was written by a student participaring in a microbiology course at the Missouri University of Science and Technology. The accuracy of the contents of this report is not guaranteed and it is recommended that you seek additional sources of information to verify the contents.
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