What Is Anthrax?

Medical Author: Edmond Hooker, MD, DrPH
Medical Editor: Melissa Conrad Stöppler, MD

Anthrax is a potentially fatal disease caused by the bacterium Bacillus anthrax. There are actually three forms or anthrax: cutaneous, pulmonary (lungs), and gastrointestinal (digestive system). Anthrax is common in nature, and prior to the advent of a vaccine in the late 19th century, the disease killed many humans and animals. Now, the disease is uncommon. The cutaneous form of the disease is usually acquired by people handling dead animal carcasses infected with bacteria. This form of the disease is rarely fatal if diagnosed and treated. The gastrointestinal form of the disease is extremely rare and is caused by ingesting infected meat. Gastrointestinal anthrax has a mortality (death) rate of 25% to 30%. Pulmonary anthrax is the most feared form of the disease. This is acquired through inhalation of spores. Historically, mortality rates of inhalation anthrax have been over 90%; however, aggressive therapy has decreased that to around 50%.

How likely is a wide scale attack with anthrax?

Although there is great fear about a bioterror attack with anthrax, it is most likely to be seen in small attacks like the one seen in 2001 in the United States. Only 22 people were infected, and five died. While this is a tragedy, it is unlikely that anyone, other than a government, would have the resources to produce large quantities of weapons-grade anthrax. Even if the anthrax is produced in large quantities, it is hard to deliver it against a population.

Can anthrax be transmitted from person to person?

Anthrax infection cannot be transmitted from person to person. However, the spores can be transmitted on contaminated clothing.

What are the symptoms of pulmonary anthrax infection?

The symptoms of anthrax infection are, unfortunately, very nonspecific. The person will have flu-like symptoms. These initially include fever, sore throat, and muscle aches. This will progress to cough, chest discomfort, and shortness of breath. Unless the physician is considering the possibility of anthrax infection, the diagnosis is likely to be missed.

Are there any tests that can help my doctor determine if I have anthrax?

Currently, there are no widely available accurate blood tests that can be used to immediately diagnosis anthrax. These specimens are sent to reference laboratories such as the U.S. Centers for Disease Control and Prevention. A chest X-ray may show some widening of the mediastinum (center part of the chest). A computed tomography (CT) scan is more sensitive (more likely to have findings if the disease is present); however, there is concern for false-positive tests (the CT is abnormal, but you do not have the anthrax infection).

Is there any way to protect myself against anthrax?

There currently is a vaccine that is only used routinely for military personnel and researchers. It has been studied extensively in adults, and there are strategic stockpiles held by the U.S. government. Unfortunately, these vaccines have not received much testing in children. If there is an attack, the government also stockpiles antibiotics to treat large numbers of the population.

REFERENCES:

Stern, E.J., K.B. Uhde, S.V. Shadomy, and N. Messonnier. "Conference Report on Public Health and Clinical Guidelines for Anthrax." Emerging Infectious Diseases 14.4 (2008): e1.

United States. Centers for Disease Control and Prevention. "Bioterrorism." <http://www.bt.cdc.gov/bioterrorism>.

Last Editorial Review: 12/12/2011 4:49:15 PM