Anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis.
Anthrax most commonly occurs in wild and domestic mammalian species (cattle, sheep, goats, camels, antelopes, and other herbivores), but it can also occur in humans when they are exposed to infected animals or to tissue from infected animals or when anthrax spores are used as a bioterrorist weapon. Visit the Anthrax & Bioterrorism webpage for more information.
How is anthrax transmitted?
Anthrax is not known to spread from one person to another.
B. anthracis spores can live in the soil for many years, and humans can become infected with anthrax by handling products from infected animals or by inhaling anthrax spores from contaminated animal products.
Most (about 95 percent) anthrax infections occur when the bacterium enters a cut or abrasion on the skin, such as when handling contaminated wool, hides, leather or hair products (especially goat hair) of infected animals.
Anthrax can also be spread by eating undercooked meat from infected animals. It is rare to find infected animals in the United States.
Anthrax spores can also be used as a bioterrorist weapon. Visit the Anthrax & Bioterrorism webpage for more information.
What are the types of anthrax infection?
Anthrax infection can occur in three forms:
What are the symptoms for anthrax?
Cutaneous: Skin infection begins as a raised itchy bump that resembles an insect bite but within 1-2 days develops into a vesicle and then a painless ulcer, usually 1-3 cm in diameter, with a characteristic black necrotic (dying) area in the center. Lymph glands in the adjacent area may swell.
Inhalation: Initial symptoms may resemble a common cold – sore throat, mild fever, muscle aches and malaise. After several days, the symptoms may progress to severe breathing problems and shock.
Gastrointestinal: The intestinal disease form of anthrax may follow the consumption of contaminated meat and is characterized by an acute inflammation of the intestinal tract. Initial signs of nausea, loss of appetite, vomiting and fever are followed by abdominal pain, vomiting of blood and severe diarrhea.
These symptoms can occur within 7 days of infection:
Fever (temperature greater than 100 degrees F). The fever may be accompanied by chills or night sweats.
Cough, usually a non-productive cough, chest discomfort, shortness of breath, fatigue, muscle aches
Sore throat, followed by difficulty swallowing, enlarged lymph nodes, headache, nausea, loss of appetite, abdominal distress, vomiting, or diarrhea
A sore, especially on your face, arms or hands, that starts as a raised bump and develops into a painless ulcer with a black area in the center.
What are the case fatality rates for the various forms of anthrax?
Early treatment of cutaneous anthrax is usually curative, and early treatment of all forms is important for recovery. Patients with cutaneous anthrax have reported case fatality rates of 20 percent without antibiotic treatment and less than 1 percent with it.
Although case-fatality estimates for inhalation anthrax are based on incomplete information, the rate is extremely high, approximately 75 percent, even with all possible supportive care including appropriate antibiotics. Estimates of the impact of the delay in postexposure prophylaxis or treatment on survival are not known.
For gastrointestinal anthrax, the case-fatality rate is estimated to be between 25 and 60 percent and the effect of early antibiotic treatment on that case-fatality rate is not defined.
How can I know my cold or flu is not anthrax?
Many human illnesses begin with what are commonly referred to as “flu-like” symptoms, such as fever and muscle aches. However, in most cases anthrax can be distinguished from the flu because the flu has additional symptoms. In previous reports of anthrax cases, early symptoms usually did not include a runny nose, which is typical of the flu and common cold.
What should I do if I think I have anthrax?
If you are showing symptoms of anthrax infection, call your health care provider right away.
Which antibiotics does CDC recommend for prevention of inhalation anthrax?
In selecting an antibiotic, the CDC will be guided by the organism's culture and sensitivity results, history of allergic reactions, age and health status factors and antibiotic availability. When no information is available about the antimicrobial susceptibility of the implicated strain of B. anthracis, initial therapy with ciprofloxacin or doxycycline is recommended for adults and children, or levofloxacin for adults.
What drugs are FDA-approved for treatment of anthrax?
Ciprofloxacin, doxycycline and penicillin are FDA-approved for the treatment of anthrax in adults and children.
Is there a vaccination for anthrax?
A protective vaccine has been developed for anthrax; however, it is primarily given to military personnel. Vaccination is recommended only for those at high risk, such as workers in research laboratories that handle anthrax bacteria routinely. The antibiotics used in post exposure prophylaxis are very effective in preventing anthrax disease from occurring after an exposure.
Is the anthrax vaccine available to the public?
A vaccine has been developed for anthrax that is protective against invasive disease, but it is currently only recommended for high-risk populations. CDC and academic partners are continuing to support the development of the next generation of anthrax vaccines.
Who should be vaccinated against anthrax?
The Advisory Committee on Immunization Practices (ACIP) has recommended anthrax vaccination for the following groups:
Persons who work directly with the organism in the laboratory.
Persons who work with imported animal hides or furs in areas where standards are insufficient to prevent exposure to anthrax spores.
Persons who handle potentially infected animal products in high-incidence areas; while incidence is low in the United States, veterinarians who travel to work in other countries where incidence is higher should consider being vaccinated.
Military personnel deployed to areas with high risk for exposure to the organism.
Can I get screened or tested to find out whether I have been exposed to anthrax?
There is no screening test for anthrax; there is no test that a doctor can do for you that says you've been exposed to or carry it. The only way exposure can be determined is through a public health investigation. Nasal swabs and environmental tests, are not tests to determine whether an individual should be treated. These kinds of tests are used only to determine the extent of exposure in a given building or workplace.
What is a nasal swab test?
A nasal swab involves placing a swab inside the nostrils and taking a culture. The CDC and the U.S. Department of Health and Human Services do not recommend the use of nasal swab testing by clinicians to determine whether a person has been exposed to Bacillus anthracis, the bacteria responsible for anthrax, or as a means of diagnosing anthrax. At best, a positive result may be interpreted only to indicate exposure; a negative result does not exclude the possibility of exposure.
Also, the presence of spores in the nose does not mean that the person has inhalation anthrax. The nose naturally filters out many things that a person breathes, including bacterial spores. To have inhalation anthrax, a person must have the bacteria deep in the lungs, and also have symptoms of the disease.
Another reason not to use nasal swabs is that most hospital laboratories cannot fully identify anthrax spores from nasal swabs. They are able to tell only that bacteria that resemble anthrax bacteria are present.
If patients are suspected of being exposed to anthrax, should they be quarantined or should other family members be tested?
Anthrax is not known to spread from one person to another. Therefore, there is no need to quarantine individuals suspected of being exposed to anthrax or to immunize or treat contacts of persons ill with anthrax, such as household contacts, friends, or coworkers, unless they also were also exposed to the same source of infection.
Where can I get more information?
Contact your doctor or the Southern Nevada Health District, Office of Epidemiology at (702) 759-1300.
Additional information about anthrax can be found on the Centers for Disease Control and Prevention’s website at http://www.cdc.gov/anthrax/.