Anthrax: Causes, Risk Factors, Symptoms, Treatment


Anthrax is a serious infection which rapidly leads to fatal outcomes if neglected. Anthrax is very rare. Anthrax, is also called as malignant pustule or woolsorter’s disease. Anthrax is caused by gram-positive bacterium called Bacillus anthrasis, which exists in both vegetative form and spore form. Anthrax is thought to have been originated in Egypt and Mesopotamia. Anthrax is the infamous black bane that swept through Europe in the 1600s, and was responsible for the cause of over 60,000 deaths in humans and cattle. In India, the states that were reported to have outbreaks of anthrax are Odisha, West Bengal, Andhra pradesh and Jharkhand with Odisha reporting the maximum number human anthrax of cases in 2009.

If you experience flu-like symptoms with the sudden onset of high fever, accompanied by skin lesions or respiratory distress, consult urgently with an Infectious Disease specialist or a General Practitioner in the Internal Medicine department to evaluate the possibility of Anthrax exposure.


Anthrax, is also called as malignant pustule or woolsorter’s disease. Anthrax is caused by Bacillus anthrasis which is a non-motile(not capable of moving), gram-positive, encapsulated rod. The bacterium has two forms vegetative form and a spore form. As the bacterium can form endospores which is resistant to a variety of conditions like heat, cold, radiation, dessication (drying) and disinfectents, it will be present in the environment for prolonged periods of time. Infection to humans with B. anthrasis are usually occurs secondary to outbreaks in animals and are usually related to the slaughter and consumption of animals which were either infected and sick or dead from anthrax. This usually occurs in places with food shortage, inadequate veterinary inspection and low vaccination coverage to animals. Bacillus cereus, Bacillus cereus biovar anthrasis (Bcbva) is reported to cause fatal infection in mammals in certain parts of Africa. However, there were very few cases reported in which humans were affected in United States.

Risk Factors

Individuals working in slaughter houses are at increased risk at being infected with anthrax which results either due to direct contact or upon exposure to infected animals and or contaminated animal byproducts (slaughterhouse waste which includes skin, bones, horns, hooves, blood, fat and offal) Veterinarians, laboratory scientists and laboratory workers who are in close contact with bacterium, textile mill workers, farmers, individuals working in slaughter houses, individuals who handle animals and animal products are at high risk for getting infected with anthrax when an animal is infected.


Recognizing the symptoms of anthrax is of significant importance as it helps prevent further spread of infection and complications. Symptoms of anthrax vary depending upon the site of exposure. A. Cutaneous anthrax is the most common form in humans which is often a localized skin infection occurring on face, neck, arms and hands. These lesions starts as pruritic papule (red coloured skin rash associated with swelling) and then these turn into vesicles (fluid filled cyst which are pimple-like) and finally these vesicles turn into black necrotic eschar (dark and dried scab) B. Systemic anthrax Ø Ingestion anthrax is when an individual consumes meat of an infected animal. Ingestion anthrax is again of two different forms a) Oropharyngeal form (infection of the mouth, base of the tongue, back part of roof of the mouth, tonsils and throat) which causes swelling of neck, respiratory insufficiency like shortness of breath, extreme weakness, inability to perform any task . b) Gastrointestinal form occurs when the spores germinates and infects the lower part of gastrointestinal tract which causes fever, chills, nausea, vomiting, headache, abdominal pain, diarrhoea (sometimes might contain blood), weakness, ascites (fluid collection in abdomen) C. Inhalation anthrax occurs due to inhalation of aerosolized spores. This mainly occurs due to processing of wool, hides, and hair from infected animals. Symptoms include fever, cough, weakness, which is followed by sudden respiratory distress(life-threatening injury to lung which causes fluid to leak into the lung), which leads to difficulty in breathing, and causes decreased oxygen supply to tissues which could be fatal.. D. Injection anthrax mainly observed in drug users who inject heroin, which is contaminated by the spores of B. anthrasis. Symptoms include deeper tissue infections and effects one or more organs in the body.


Diagnosing of anthrax is important for providing effective treatment and to prevent the spread of infection to others. The health care individual might advise a series of test depending upon the clinical presentation. The tests might include PCR, gram stain (methylene blue stain a special stain which helps in finding the gram-positive rods when observed under a microscope) and aerobic and anaerobic cultures from blood, from ulceration site of skin, cerebrospinal fluid (CSF) by doing a lumbar puncture, pleural fluid and stool. The healthcare professional may also advise routine investigations like CBP, liver function test and Chest X-ray and CT which would be exceptionally helpful in case of inhlation anthrax.


The treatment of anthrax should be not be neglected because of its capability to cause death rapidly,and there would be better chances of recovery in the early stages of infection. The contaminated individuals should immediately wash hands with soap and water and be isolated and all the clothes should be placed in a plastic bag . The treatment includes different antimicrobial agents which are given intravenously and orally for cutaneous anthrax, inhalation anthrax and systemic anthrax. The duration of treatment for cutaneous anthrax is around 3-7days and for for systemic anthrax it is 3-4 weeks. However, antibiotics are advised for 60 days in case of inhalation anthrax as the spores that remain in the body might take that long to germinate. Monoclonal antibodies would be used in combination with antibiotics in case of inhalation anthrax. Anthrax vaccines are available for both humans and animals and post-exposure schedule would be advised for the infected individuals. Pre-exposure prophylaxis schedule is recommended for exposed community members.

Preventive Measures

Ø Anthrax can be controlled by vaccinating all the grazing animals in areas where anthrax cases were reported and also by implementing control measures in areas where the was an outbreak of anthrax. Ø Individuals working in close contact with animals should always wear vinyl or nitrile gloves, eye glasses, face and respiratory protection in order the prevent the skin contact with animals and animal products. Ø Preventative antibiotics may be recommended to individuals who were suspected to have been exposed to anthrax. Ø Individuals infected with anthrax should always be quarantined and complete the recommended treatment.

Do's & Don’t's

Do's Don't
Ensure domestic farm animals are vaccinated at 3 months, 6 months, and annually.  Neglect vaccinations for domestic farm animals. 
Quarantine oneself if infected with anthrax to prevent spread.  Ignore the need for self-quarantine when infected.
Report anthrax infection to local authorities promptly.  Delay or avoid notifying local authorities of anthrax infection.

If you experience flu-like symptoms with the sudden onset of high fever, accompanied by skin lesions or respiratory distress, consult urgently with an Infectious Disease specialist or a General Practitioner in the Internal Medicine department to evaluate the possibility of Anthrax exposure.

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