Anthrax

Definition

Definition of Anthrax
Anthrax is an acute disease caused by the bacterium Bacillus anthracis. Most forms of the disease are lethal, and it affects both humans and other animals. There are effective vaccines against anthrax, and some forms of the disease respond well to antibiotic treatment.

Symptoms

Symptoms of Anthrax
Symptoms of anthrax differ depending on the type of anthrax.

Symptoms of cutaneous anthrax start 1 to 7 days after exposure:

1. An itchy sore develops that is similar to an insect bite. This sore may blister and form a black ulcer (sore).
2. The sore is usually painless, but it is often surrounded by swelling.
3. A scab often forms, and then dries and falls off within 2 weeks. Complete healing can take longer.

Symptoms of inhalation anthrax:

1. Begins with fever, malaise, headache, cough, shortness of breath, and chest pain
2. Fever and shock may occur later

Symptoms of gastrointestinal anthrax usually occur within 1 week and may include:

1. Abdominal pain
2. Bloody diarrhea
3. Diarrhea
4. Fever
5. Mouth sores
6. Nausea and vomiting (the vomit may contain blood)

Causes

Causes of Anthrax
Anthrax commonly affects hoofed animals such as sheep, cattle, and goats, but humans who come into contact with 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 spores touch a cut or scrape on the skin.

• It is the most common type of anthrax infection.
• The main risk is contact with animal hides or hair, bone products, and wool, or with infected animals. People most at risk for cutaneous anthrax include farm workers, veterinarians, and tannery and wool workers.

Diagnosis

Diagnosis of Anthrax
A culture of the skin, and maybe a biopsy, are done on the skin sores. The sample is looked at under a microscope to identify the anthrax germ.

Tests may include:

1. Blood culture
2. Chest CT scan or chest x-ray
3. Spinal tap to check for infection around the spinal column
4. Sputum culture

Treatment

Treatment of Anthrax
Most people with anthrax are treated with antibiotics. Several antibiotics are effective, including penicillin, doxycycline, and ciprofloxacin.

When treating inhalational anthrax, a combination of antibiotics should be used. Doctors often start treatment with ciprofloxacin plus another drug, given through a vein (intravenously). The length of treatment is about 60 days for people who have been exposed to anthrax, because it may take spores that long to germinate.

Cutaneous (skin) anthrax is treated with antibiotics taken by mouth, usually for 7 to 10 days. Doxycycline and ciproflaxin are most often used.

Prognosis

Prognosis of Anthrax
When treated with antibiotics, cutaneous anthrax is likely to get better. However, up to 20% of people who do not get treatment may die if anthrax spreads to the blood.

People with second-stage inhalation anthrax have a poor outlook, even with antibiotic therapy. Up to 90% of cases in the second stage are fatal.

Prevention

Prevention of Anthrax
There are two main ways to prevent anthrax.

For people who have been exposed to anthrax (but have no symptoms of the disease), doctors may prescribe preventive antibiotics, such as ciprofloxacin, penicillin, or doxycycline, depending on the strain of anthrax.

An anthrax vaccine is available to military personnel and some members of the general public. It is given in a series of five doses over 18 months.