Anthrax Health Article

Definition

Anthrax is an infectious disease caused by bacteria called Bacillus anthracis. Infection in humans most often involves the skin, the gastrointestinal tract, or the lungs.

Alternative Names

Woolsorter's disease; Ragpicker's disease; Cutaneous anthrax; Inhalation anthrax; Gastrointestinal anthrax

Causes, incidence, and risk factors

Anthrax commonly affects hoofed animals such as sheep and goats, but humans who come into contact with the infected animals can get sick from anthrax, too. In the past, the people who were most at risk for anthrax included farm workers, veterinarians, and tannery and wool workers.

There are three main routes of anthrax infection:

• Cutaneous anthrax occurs when anthrax touches a cut or scrape on the skin.
• Inhalation anthrax develops when anthrax spores enter the lungs through the respiratory tract.
• Gastrointestinal anthrax occurs when someone eats anthrax-tainted meat.

Anthrax may be used as a biological weapon or for bioterrorism. In 2001, anthrax sent through the U.S. Postal Service infected 22 people; 7 survivors had confirmed cutaneous anthrax disease.

While at least 17 nations are believed to have a biological weapons program, it is unknown how many nations or groups are working with anthrax. Most bioterrorism experts have concluded that it is difficult to use anthrax effectively as a weapon on a large scale.

Symptoms

Symptoms of anthrax differ depending on the type of anthrax.

Symptoms of cutaneous anthrax:

• Blister or ulcer that later forms a black scab
• Blister or ulcer is usually surrounded by a lot of swelling

Symptoms of inhalation anthrax:

• Begins with fever, malaise, headache, cough, shortness of breath, and chest pain
• Shock may occur later

Symptoms of gastrointestinal anthrax usually develop within one week and can affect the mouth, esophagus, intestines, and colon. Symptoms may include:

• Nausea and vomiting (the vomit may include blood)
• Anorexia
• Bloody diarrhea

Signs and tests

The tests to diagnose anthrax depend on the type of disease suspected.

Tests may include:

• Culture of skin sore to test for cutaneous anthrax
• Chest x-ray
• Sputum culture
• Spinal tap to check your spinal fluid for infection (See:CSF culture)
• Gram stain (staining a sample of tissue and looking at it under a microscope for the bacteria that cause anthrax infection)

Tissue or fluid samples may be sent to a special lab for more detailed testing, including immunofluorescence.