Anthrax is an acute disease in humans and animals that is caused by the bacterium Bacillus anthracis and is highly lethal in some forms. Anthrax is a bacteria that can form long-lived spores. When the bacteria’s life cycle is threatened by factors such as lack of food caused by their host dying or by a change of temperature, the bacteria turn themselves into more or less dormant spores to wait for another host to continue their life cycle.

History:- The word anthrax is the Greek word for coal. The germ’s name is derived from anthrakitis, the Greek word for anthracite, in reference to the black skin lesions victims develop in a cutaneous skin infection. Anthrax was first known to infect animals in the year 17 BC when a French farmer noticed his sheep flock suddenly dying. It was shown to cause disease by Robert Koch in 1877.

Description of Bacteria:- Bacillus Anthracis is a rod-shaped Gram-positive bacterium, about 1/9 micrometers in size.  The bacterium  normally rests in endospore form in the soil, and can survive for decades and perhaps centuries in this state. Anthrax most commonly occurs in  wild and domestic grass-eating mammals (ruminants). Ruminants are often infected whilst grazing, especially when grazing rough, irritant or spiky vegetation- the vegetation causes wounds within the gastrointestinal tract permitting entry of the bacterial endospores into the tissues. Anthrax can also be caught by humans when they are exposed to dead infected pigs, eat tissue from infected animals, or are exposed to a high density of anthrax spores from an animal’s fur, hide, or wool. Anthrax cannot spread directly from human to human; but anthrax spores can be transported by human clothing, shoes etc. and if  a person dies of anthrax his body can be a very dangerous source of anthrax spores.

Effects:- Once ingested by a ruminant or placed in an open cut, the bacterium begins multiplying inside the animal or human and in a few days to a month kills it. The endospores germinate at the site of entry into the tissues and then spread via the circulation to the lymphatics, where the bacteria multiply. Once in the lymph glands, the spores germinate into active bacillus, that multiplies, and eventually bursts the macrophage cell, releasing many more bacilli into the bloodstream which are transferred to the entire body. Once in the blood stream these bacilli release a tripartite toxin (composed of lethal factor, oedema factor and protective antigen) which is known to be the primary agents of tissue destruction, bleeding, and death. If antibiotics are administered too late, even if the antibiotics eradicate the bacteria, some people will still die. This is because the toxins produced by the bacilli remain in their system at lethal dose levels. Anthrax spores can be grown outside the body and used as a biological weapon.              However, recent evidence indicates that anthrax also targets endothelial cells (cells that lines serous cavities, lymph vessels, and blood vessels), causing vascular leakage (similar to hemorrhagic bleeding), and ultimately hypovolemic shock (low blood volume), and not only septic shock. In other words, the patient bleeds to death internally.

Types of Anthrax:- Anthrax can enter the human body through the intestines , lungs, or skin  and causes distinct clinical symptoms based on its site of entry.

Pulmonary (respiratory) anthrax:-

Respiratory infection initially presents with cold or flu-like symptoms for several days, followed by severe (and often fatal) respiratory collapse. This disease can rarely be treated, even if caught in early stages of infection. This  anthrax is highly fatal, with near 100% mortality. This inhalation anthrax is also known as Woolsorters’ disease or as Ragpickers’ disease since these people often caught it.

Gastrointestinal (gastroenteric) anthrax:-Gastrointestinal infection is most often caused by eating anthrax-infected meat. It is characterized by serious gastrointestinal difficulty, vomiting of blood, severe diarrhoea, acute inflammation of the intestinal tract, and loss of appetite. Some lesions have been found in the intestines and in the mouth and throat.  Gastrointestinal infections can be treated but usually result in fatality rates of 25% to 60%, depending upon how soon treatment commences.

 Cutaneous (skin) anthrax:- Anthrax skin lesion. Cutaneous  anthrax infection shows up as a boil-like skin lesion that eventually forms an ulcer with a black centre. The black eschar often shows up as a large, painless necrotic ulcer.  Cutaneous infections generally form within the site of spore penetration within 2 to 5 days after exposure. Cutaneous infection is the least fatal form of anthrax infection if treated. But without treatment, approximately 20% of all cutaneous skin infection cases may progress to toxemia and death.

Treatment and pre- vention:- The patient’s clothing and body  contaminated with anthrax spores must be  thoroughly wash down with anti-microbe effective soap and water. Waste water should be treated with bleach or other anti-microbial agent. Effective decontamination of articles can be accomplished by boiling contaminated articles in water for 30 minutes or longer and using common disinfectants. Chlorine is effective in destroying spores and vegetative cells on surfaces. Burning clothing is also effective.  If death occurs from anthrax the body should be isolated to prevent possible spread of anthrax germs. The victim should be sealed in an airtight body bag. Burial does not kill anthrax spores.                       

            Early antibiotic treatment of anthrax is essential. Treatment for anthrax infection and other bacterial infections includes large doses of intravenous and oral antibiotics, such as fluoroquinolones, like ciprofloxacin (cipro), doxycycline, erythromycin, vancomycin or penicillin. 

              Delays of only a few days may make the disease untreatable. The treatment should be started even without symptoms if possible contamination or exposure is suspected. Animals with anthrax often just die without any apparent symptoms. Initial symptoms may resemble a common cold – sore throat, mild fever, muscle aches and malaise. After a few days, the symptoms may progress to severe breathing problems and shock and ultimately death.

Aerial spores can be trapped by a simple HEPA or P100 filter. Inhalation of anthrax spores can be prevented with a full-face mask using appropriate filtration. Unbroken skin can be decontaminated by washing with simple soap and water. All of these procedures do not kill the spores which are very hard to kill and require extensive treatment to eradicate them. In recent years there have been many attempts to develop new drugs against anthrax; but the existing supply still works fine if treatment is started soon enough.