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Updated: 10 Jun 1998
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Information Paper
Anthrax as a Biological Warfare Agent
- Anthrax is the preferred biological warfare agent
because:
- 100 million lethal doses per gram of anthrax
material (100,000 times deadlier than the
deadliest chemical warfare agent).
- Silent, invisible killer.
- Inhalational anthrax is virtually always fatal.
- There are low barriers to production.
- Low cost of producing the anthrax material.
- Not high-technology. Knowledge is widely
available.
- Easy to produce in large quantities.
- It is extremely stable. It can be stored almost
indefinitely as a dry powder.
- It can be loaded, in a freeze-dried condition, in
munitions or disseminated as an aerosol with
crude sprayers.
- Currently, we have a limited detection capability.
- Anthrax is a naturally occurring disease of plant
eating animals (goats, sheep, cattle, wine, etc.)
caused by the bacterium Bacillus anthracis.
- It is an illness which has been recognized since
antiquity. Anthrax was common in essentially all
areas where livestock are raised. Intensive livestock
immunization programs have greatly reduced the
occurrence of the disease among both animals and
humans in much of the world, an most outbreaks occur
in areas where immunization programs have not been
implemented or have become compromised (primarily
Africa and Asia; however, outbreaks occurred during
the mid- I 990's in Haiti and the former Soviet
Union).
- Anthrax spores can remain viable for several decades
under suitable environmental conditions; thus,
absence of cases does not equate to absence of risk.
- Humans can contract anthrax in three ways:
- Through cuts or breaks in the skin resulting from
contact with an infected animal (cutaneous
anthrax), resulting in local and possibly
systemic (bloodstream) infection.
- From breathing anthrax spores (termed
"woolsorters" disease) resulting in an
infection of the lungs (inhalational anthrax).
- From eating infected meat, resulting in
gastrointestinal infection (gastrointestinal
anthrax). Gastrointestinal anthrax is generally
not considered a threat to U.S. forces.
- Symptoms of anthrax begin after a 1 to 6 day
incubation period following exposure.
- For contact or cutaneous anthrax, itching will
occur at the site of exposure followed by the
formation of a lesion. Untreated contact anthrax
has a fatality rate of 5-20 percent, but with
effective antibiotic treatment, few deaths occur.
- Initial symptoms for inhalational anthrax are
generally non-specific: low grade fever, a dry
hacking cough, and weakness. The person may
briefly improve after 2 to 4 days; however within
24 hours after this brief improvement,
respiratory distress occurs with shock and death
following shortly thereafter.
- Almost all cases of inhalational anthrax, in which
treatment was begun after patients have exhibited
symptoms, have resulted in death, regardless of
post-exposure treatment.
- What is the medical countermeasure?
- Prior to exposure, prevention through vaccination, using
the FDA-licensed vaccine.
- Otherwise, antibiotics such as penicillin,
ciprofloxacin, and doxycycline are the drugs of
choice for treatment of anthrax.
- Treatment with antibiotics must begin prior to
the onset of symptoms and must include vaccination
prior to discontinuing their use.
- The use of antibiotics keep the patient alive until
their body can build an immunity to anthrax via
vaccination. After symptoms appear however,
inhalational anthrax is almost always fatal,
regardless of treatment.
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