Anthrax is an infection caused by a bacterium called
Bacillus anthracis. Anthrax is usually a disease of animals (such as
cattle, sheep, pigs, horses, goats, camels, and antelopes) but it can also occur
in humans who are exposed to animals or tissues of infected animals or to
Bacillus anthracis spores (a version of the bacterium in a hard shell).
Anthrax can be found worldwide, but it is much more
common in developing countries or countries without veterinary public health
programs, including South and Central America, Southern and Eastern Europe,
Asia, Africa, the Caribbean, and the Middle East.
Why was anthrax prominent in the news?
Anthrax was prominent in the news because anthrax
spores have been used in intentional acts of bioterrorism in the United States
shortly after 9/11/01. Even a very tiny amount of anthrax spores can be
aerosolized and inhaled by humans and result in morbidity and mortality.
However, is highly unlikely that you or someone you know will contract anthrax.
Aside from the people who contracted anthrax from spores delivered through the
US mail in bioterrorist acts, there have been few cases of anthrax infection
reported in the United States. Most were associated with handling infected
animals or animal products.
What are the symptoms of anthrax?
There are three types of anthrax infections in humans.
Cutaneous (skin-derived) anthrax
Cutaneous anthrax accounts for 95 percent of anthrax
cases and occurs when the bacterium enters a cut or abrasion on the skin.
Typically, the infection occurs through handling the wool, hide, leather, or
hair of animals infected with anthrax. The anthrax skin infection in humans
begins as a raised itchy bump that resembles an insect bite. Then, 1 to 2 days
later, the bump develops into a painless lesion or ulcer with a characteristic
black area in the center. The lymph glands in nearby area may swell. If left
untreated, about 20 percent of individuals with cutaneous anthrax die. However,
deaths are rare with appropriate antimicrobial therapy.
Intestinal anthrax occurs after eating contaminated
meat and results in an acute inflammation of the small intestinal tract. This is
very uncommon in the United States. Initial symptoms include nausea, loss of
appetite, and fever followed by abdominal pain, vomiting of blood, and severe
diarrhea. Death occurs in 25 percent to 60 percent of individuals infected with
Inhalational anthrax is extremely rare but can occur
if someone breathes anthrax spores, which are kicked up into the air by mail
sorting machines or released through a bioterrorist act. The anthrax spores are
inhaled into the lungs. The initial symptoms may be nonspecific cold, sore
throat, or flu (without the muscle aches) symptoms, but after a few days, the
symptoms may progress to severe breathing problems and shock and spread into the
central nervous system.. Inhalation anthrax is often fatal without early
recognition and treatment.
It usually takes less than 7 days for symptoms of skin
and intestinal anthrax to appear. However, symptoms can appear as early as 48
hours after the lungs have been exposed to anthrax spores.
Can anthrax be spread from person to person?
No. Anthrax is not a contagious disease. It cannot be spread from person-to-person.
How is anthrax diagnosed?
Anthrax is definitively diagnosed by isolating the bacterium, Bacillus anthracis,
from the blood, skin lesions, or cerebrospinal fluid.
How is anthrax infection treated?
Several different antibiotics, (including
ciprofloxacin and doxycycline) can kill Bacillus anthracis if diagnosed
early. Cutaneous anthrax is often caught in an early stage because of its
telltale signs. However, inhalation anthrax may be mistaken for other common
illnesses and therefore, is often not diagnosed until severe symptoms appear. At
this stage, antibiotic treatment is ineffective. For this reason, researchers
are working on developing other effective treatments including combinations of
antibiotics and antibodies and gene-based therapies. An anthrax vaccine has been
available since the 1970s and is used primarily for military troops deployed in
"high risk" areas.
Who should receive the anthrax vaccine?
The vaccine is currently recommended for use by those
at most risk for occupational exposure to the bacteria such as:
- military personnel (due to exposure as a biological warfare weapon)
- laboratory workers
- livestock handlers
- people who work with animal hides or furs imported from areas of the
world where the disease is common
- people who handle potentially infected animal products from areas where
the disease is common
Will the anthrax vaccine become more widely available to the public?
Health officials currently do not recommend the
vaccine for general use by the public because of the rarity of anthrax
infection. In addition, the vaccine can’t be practically given in response
to a bioterrorism act due to its prolonged administration schedule – the vaccine
is given as six subcutaneous injections over the course of 18 months. If
diagnosed early, anthrax can be successfully treated with antibiotics.
Researchers are working to develop a second generation anthrax vaccine as well
as other treatment options to protect the public in the event of a bioterrorism attack.
Where can I learn more?
CDC Hotline: 800.232.4636
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