- What is anthrax?
- How common is anthrax and how is it spread?
- What are the symptoms and how soon do they develop after exposure?
- How is anthrax diagnosed?
- Can anthrax be spread from person to person?
- What is the treatment for illness caused by anthrax?
- Is there a vaccine available?
- Anthrax as a bioterrorist weapon
Anthrax is a serious infection caused by a bacterium called Bacillus anthracis.
Anthrax occurs naturally around the world in wild and domestic animals, especially hoofed animals such as cattle, sheep, goats, camels and antelopes. The spores of B. anthracis can remain viable in the soil for many years, and can be a potential source of infection for livestock through ingestion. It is rare to find infected animals in the United States. Humans can also get anthrax, and usually it is due to an occupational exposure to infected animals or their products (cutaneous anthrax). Infection can also result from inhaling anthrax spores that have been aerosolized (inhalational anthrax), or by eating undercooked meat from infected animals (gastrointestinal anthrax).
The illness a person gets when they are infected with B. anthracis depends on how the bacteria got into the person’s body.
- Inhalational anthrax is the most serious form of anthrax and is caused by inhaling the bacterial spores into the lungs. Woolsorters’ disease is a rare endemic infection that occurs among workers handling infected hides, wools, furs and especially goat hair. The first symptoms usually begin 1-6 days after exposure, but can occur as late as 60 days later. Symptoms include fever, headache, cough, difficulty breathing, chills, weakness, and chest discomfort. Without treatment, severe breathing problems and death usually result.
- Cutaneous anthrax is caused when the bacteria come into direct contact with skin that has a cut or a break in it. About 7 days after exposure, a raised, itchy bump that looks like an insect bite appears. After 1-2 days, a small blister develops, which later becomes a painless sore with a black center. Lymph glands in the area of infection may become swollen.
- Intestinal anthrax is caused by eating meat from an animal that has died of anthrax or by drinking liquids contaminated with anthrax bacteria. Within 1 to 7 days after exposure, symptoms appear. These include nausea, vomiting with blood, fever, pain in the abdomen and diarrhea.
If left untreated, each of these forms of anthrax can spread to the blood or brain and cause severe illness or even death.
The bacteria that cause anthrax can be grown from the blood, skin lesions or respiratory secretions. Special tests to confirm the identification are performed at reference laboratories. Antibody tests and tests to look for anthrax DNA in tissue or blood specimens are also available at specialized labs. There is no laboratory test for anthrax before symptoms begin. Nose swabs are NOT useful to test for anthrax.
A person who has cutaneous anthrax, with draining open sores, presents a low risk of infection to others. The only way cutaneous anthrax can be spread is by direct contact with the draining. Inhalational anthrax is NOT transmitted from person to person, by casual contact, sharing office space, coughing or sneezing. Even when people have developed symptoms of inhalational anthrax they are not contagious to others.
There are several antibiotics that are used successfully to treat anthrax. Treatment is highly effected in cases of cutaneous anthrax and is effective in inhalation and gastrointestinal anthrax if begun early in the course of infection.
Currently, the only available vaccine is for military personnel who are thought to be at a higher risk for exposure to anthrax in combat settings, or certain civilian workers who may come in contact with anthrax spores in the course of their work. There is no anthrax vaccine that is available commercially.
After the terrorist attacks of September 11, 2001 and reports of anthrax transmission through the U.S. mail, public concern about a biological attack with anthrax heightened.
While we have heard of successful transmission of this infection to individuals, the risk of a successful large-scale biological attack in the U.S. is still considered by experts to be low. Nevertheless, state and local government, hospitals and the medical community have been working over the past few years to improve emergency response and to increase capacity to detect unusual illnesses and prevent their spread. The Vermont Department of Health is also working with other state agencies such as The Department of Public Safety/Emergency Management, to coordinate emergency response plans.
The federal government also has a range of resources that they can share with states during an emergency. The Centers for Disease Control and Prevention (CDC) works closely with other federal agencies and the states to provide public health assistance where needed. The CDC also maintains a stockpile of medicines and supplies that can be moved to wherever they are needed.