What exactly is anthrax, and should you be concerned about
it?
Anthrax is an infection caused by a bacterium (a type of
germ
) called
Bacillus anthracis
(
B. anthracis
). Although it's most commonly seen in grazing animals like
sheep, pigs, cattle, horses, and goats, anthrax can also occur in
humans - although it's very rare.
In the environment, the anthrax-causing bacterium forms
spores
(a version of the germ covered by a hard protective shell) that can
live in the soil for years. People can become infected by coming
into contact with these spores through a break in the skin (such as
a cut or scrape), by eating food (usually undercooked meat)
contaminated by them, or by inhaling spores (breathing them into
the lungs). But anthrax is
not
contagious, which means that it can't spread from person to
person.
It's extremely unlikely that you or someone you know could
get anthrax. In fact, there are usually only one or two reported
cases of anthrax per year. Most of these have been in people who
work with animals or animal products.
Why Are People So Concerned About Anthrax?
Anthrax that occurs naturally in the environment isn't a
huge threat. But
B. anthracis
can be grown in a laboratory and some people are worried about
anthrax germs being grown as a weapon.
The issue of laboratory-grown
B. anthracis
received lots of attention in 2001 after an anthrax outbreak
in the United States. The outbreak scared a lot of people, in part
because five people died (which is very rare) and also because the
outbreak coincided with the September 11 terrorist attacks.
However, bioterrorism experts believe that it is technologically
difficult to use anthrax effectively as a weapon on a large
scale.
What Are the Signs of Anthrax?
The three main types of anthrax are:
- Cutaneous
or skin anthrax, can occur if someone with a cut or scrape
handles contaminated animals or animal products. More than 95% of
anthrax cases are of the cutaneous type, which is the least
dangerous form. A person with cutaneous anthrax will notice a
small sore that develops into a painless ulcer with a black area
in its center. If left untreated, the infection can spread to
other areas of the body.
- Intestinal
anthrax can occur if someone eats undercooked contaminated meat.
Intestinal anthrax is far less common than cutaneous anthrax, but
it can make someone much sicker. Intestinal anthrax symptoms
include severe abdominal pain, nausea, vomiting, severe diarrhea,
and bleeding from the digestive tract.
- Pulmonary
, or inhaled, anthrax is the rarest form of anthrax - but
it's also the most dangerous. Pulmonary anthrax can only
occur if someone breathes thousands of anthrax spores into the
lungs. Pulmonary anthrax usually seems like a common cold or the
flu at first, but it rapidly turns into severe
pneumonia
and requires hospitalization.
It usually takes fewer than 7 days for a person to show signs of
anthrax after being infected. However, symptoms of pulmonary
anthrax can sometimes take months to appear.
How Difficult Is It to Get Anthrax?
It's
very
difficult to get anthrax. Just being exposed to the spores or
coming into contact with an infected animal doesn't mean that a
person will automatically develop the disease.
For example, to get pulmonary anthrax (the type of anthrax that
killed the five people in the 2001 outbreak), a person has to
inhale thousands of spores. This is extremely difficult to do when
the anthrax spores are found in soil or on infected animals.
Even in the case of the manmade outbreak in 2001, several of the
people who were exposed were found to have
B. anthracis
spores only in their nostrils when tested. These spores hadn't
made it to their lungs in sufficient amounts to cause a problem. In
other words, the people had been exposed to the bacteria but had
not developed the disease.
How Is Anthrax Diagnosed and Treated?
Medical professionals can diagnose anthrax by taking samples
from the skin sores, blood, or other bodily fluids of people
who are believed to have been exposed to
B. anthracis
. These samples are then sent to a lab to check whether the person
has the bacteria in his or her system.
If anthrax is caught early, it is almost always successfully
treated with antibiotics. If a person is known to have been exposed
to
B. anthracis
but has no signs or symptoms of the disease, antibiotics may
be given (after exposure) to prevent the disease from
occurring.
Although there is a vaccine for anthrax, in the United States it
is currently only recommended for people who are at risk of coming
into contact with
B. anthracis
. They include people who work with
B. anthracis
in laboratories, people who handle potentially infected animal
products, and U.S. military personnel. The vaccine is not given
routinely to people in the United States and it hasn't been
studied for use in people younger than 18.
If you worry when you hear about anthrax, remember that it's
very rare, and it's unlikely that you will ever be exposed to
the germs that cause anthrax. If you're worried about it, talk
to a science teacher or medical professional - someone who can help
you find the answers to any questions you may have about
anthrax.
Reviewed by:
Elana Pearl Ben-Joseph, MD
Date reviewed: September 2006
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
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