All About Anthrax: What You Need to Know About this Deadly Bacterium
Bacillus Anthracis, more commonly known as Anthrax, is a spore-based bacterium that has the ability to infect all warm-blooded animals including humans. Fortunately, it is very uncommon for humans to become infected with this deadly bacteria. In almost all documented cases of Anthrax infection throughout history, the victim came into contact with an infected animal. In fact, the incidence rate is so low that it is listed as a "rare disease" by the Office of Rare Diseases of the National Institutes of Health.
History of Anthrax
Descriptions and accounts of Anthrax can be found as early as 1500 B.C. Some historians believe that the fifth and sixth plaques of Egypt were caused by Anthrax. Later on, the Roman poet Virgil wrote extensively on this rare and deadly diseases. Between this period and the late 1800s, there were several documented cases of Anthrax killing livestock around the world. In 1876, Robert Koch began experimenting with anthrax. This eventually led him to develop the original theory of bacteria and disease. In 1880, the first successful Anthrax vaccine was developed and used on livestock
Ok, It Sounds Bad, but What Else?
Anthrax is an occupational disease. It is commonly found in agricultural regions all over the world that contain livestock. Humans that contract the disease are usually workers who are exposed to infected dead animals or animal products. Anthrax can is contracted by contact with an infected animal, inhalation of spores found in contaminated soil, or through consumption of undercooked and contaminated meat. Even though the disease can be contracted through these mediums, there has been no evidence that person-to person transmission of Anthrax is possible.
Anthrax can infect you in three common ways: 1) Skin Contact (Cutaneous Anthrax), 2) Inhalation Anthrax, and 3) Ingestion (Gastrointestinal Anthrax).
Of the three infectious pathways listed, inhalation Anthrax is by far the most deadly. Inhaled spores enter the lungs and begin to rapidly spread and kill the tissues that they infect. The infection begins with cold-like symptoms, but within seven days serious breathing problems, profuse sweating, and cyanosis (blue colored skin) begin to occur. Shock and death occur following the symptoms within ten days. Almost all cases of inhalation Anthrax result in death regardless if treatment is given or not.
Gastrointestinal Anthrax affects the intestines and stomach. The symptoms of intestinal Anthrax include: inflammation of the intestinal tract, nausea, loss of appetite, vomiting, fever followed by abdominal pain, vomiting of blood, and severe diarrhea. Sixty percent of all untreated cases result in death.
The cutaneous form of Anthrax produces blister-like lesions that appear on the skin within 2 days of first contact. The lesions usually grow to about an inch wide and turn black. Fortunately, cutaneous anthrax is very often successfully treated. The cutaneous anthrax death rate is 20 percent without antibiotic treatment and less than 1 percent with it.
The diagnosis of Anthrax can be determined in many ways. Blood cultures, skin examinations, and testing of respiratory secretions are common methods. Other methods include x-rays of the chest, spinal taps, and antibody measurements. All three types of Anthrax are treated with antibiotics such as penicillin or tetracycline.
Anthrax can be prevented with a vaccine. Vaccination typically occurs over a period of 18 months with a booster shot given every year. Those in the military and those who work around livestock are the only ones who need to be vaccinated. The vaccine is a cell-free filtrate vaccine; this means that it contains no dead or live bacteria in the preparation. Many people in the military are opposed to taking the vaccine because of possible adverse reactions to the it and the fact that the long-term side effects aren't well known. The most common adverse reactions to the vaccine are extensive swelling of the forearm and acute cold-like symptoms. The vaccine is about ninety-three percent effective in protecting against cutaneous Anthrax and intestinal Anthrax. It is not known if the vaccine is effective against inhalation Anthrax because it has not been tested yet.
Anthrax In Bio-Warfare and Terrorism
Anthrax is an ideal bacterium for use as a biological weapon for at least four reasons. First, it is very easy to grow in large quantities. Second, the spores can be dry-stored for years without losing their effectiveness. (Anthrax spores can only be destroyed by steam sterilization or burning, not by disinfectants.) Third, it is highly incapacitating and fatal to its victims. And four, it can be deployed without no obvious signs of an attack; there is no cloud or colored vapor, nor is there any smell or taste. Since Anthrax is so suitable to use as a weapon, it is not surprising that it has been used in several terrorist attacks around the globe in recent years.
References and Resources
Clinaero, Inc. "Anthrax Death Rate." eMedTV. June 8, 2011. <http://anthrax.emedtv.com/anthrax/anthrax-death-rate.html>
CNN Health. "Timeline: Anthrax Through the Ages." October 16, 2001. <http://articles.cnn.com/2001-10-16/health/anthrax.timeline_1_anthrax-outbreak-deadly-anthrax-disease-anthrax-weapons?_s=PM:HEALTH>
Health Grades, Inc. "Statistics about Anthrax." Right Diagnosis. February 1, 2012. <http://www.rightdiagnosis.com/a/anthrax/stats.htm>
Sternbach, G. "The History of Anthrax." Department of Emergency Medicine, Stanford University Medical Center. May 24, 2003. <http://www.ncbi.nlm.nih.gov/pubmed/12745053>