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Biological Weapons
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Biological Weapons
What are biological weapons?
Biological weapons are any infectious agent such as bacteria or virus, or chemicals extract
from microorganisms when used intentionally to inflict harm upon others. The most commonly
recognized agents or chemicals that can be used as biological weapons are: Anthrax (炭疽菌),
Smallpox (天花病毒), Black death (鼠疫), Botulinum (肉毒桿菌), Ricin (蓖麻毒), Tularemia (兔
熱病菌) and Marburg hemorrhagic Fever (馬爾堡病). Some of these agents and chemicals are
highly lethal and can cause a lot of death.
Anthrax
Anthrax is caused by the bacteria, Bacillus anthracis. It is an
ancient disease of livestock and humans, which is usually found in
sheep, cattle and horses. It can transmitted to humans who
contact infected animals or their products. Human can contract
anthrax in three ways:
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Through cuts or breaks in the skin resulting from contract
with infected animal.
From breathing anthrax spores.
From eating infected meat.
Symptoms of anthrax begin after 1 to 6 days after infection. If the infection is on skin,
itching will occur at the infected area followed by the formation of a black lesion. It can be cured
with effective antibiotic treatment, few deaths occur. If the infection is in lung, the symptoms are
similar to common cold: low grade fever, a dry hacking cough, and weakness. The person may
briefly improve after 2 to 4 days, and within 24 hours after this brief improvement, respiratory
distress occurs with shock and the person soon dead. If the infection is in the alimentary canal, it
will cause vomiting, abdomen-ache, high temperature and diarrhoea occurred. It causes death too.
The diseases caused can be treated with antibiotics, but it must begin prior to the onset of
symptoms. 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.
Anthrax is preferred to make biological weapon because:
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Highly lethal.
Easily to spread over. (It is extremely stable which can be stored almost indefinitely as a dry
powder. It can also be loaded, in a freeze-dried condition or distribute as an aerosol with
sprayers.)
Inhalational anthrax is virtually always fatal and can cause a lot of death.
Biological Weapons
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Small pox
Smallpox was a highly infective human disease caused by the
virus variola. It can spread through air by direct contact to patients.
As it s very stable in the environment, it is not easy to be destroyed.
It has a high death rate of 30 %.
Symptoms of Smallpox are characterized in its classical form by the
sudden onset of fever, headache, backache and vomiting. Early in the illness
there may appear in about 10% of patients a fleeting rash in the form of a
reddening of the skin. About two to three days after the onset of illness the
true smallpox rash appears. These rashes eventually dry up to become hard
crusts and separate leaving a sunken scar. The hard material always contains
smallpox virus in it.
Small pox can be prevented by vaccination. Human can be introduced
to attenuated smallpox virus and a trivial infection occurs. After the
vaccination, he/she can protect for lifelong, or at least 10 years.
Smallpox is preferred to be an effective biological weapon because:
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Highly infectious. (It is communicable from person to person)
Small dose is enough.
High death rates. (No treatment)
Easy to spread over by aerosol release.
Black Death
Black death is caused by a bacterium called Yersinia pestis. This
bacterium has a life cycle involves two hosts, rat and the flea Xenopsylla
cheopis. The infection is through the bite from the infected flea, which
carried the bacteria in their gut, or direct bit of the infected rats. It can also
be infected by directly inhale the plague aerosol.
Symptom of the black death are enlarged and inflamed lymph nodes around arm pits, neck and
groin. Victims will have headaches, nausea, aching joints, fever, vomiting, skin turning deep
shades of purple. Symptoms took at most 7 days to appear. The mortality rate is about 90-100 %.
The victims of this disease can be cured by prophylaxic antibiotics if caught early, which can reduce
the mortality rate to 10-15 %.
Black death, as it needs flea and rats as media, can be prevented by clearance of these media.
A better sanitation environment can prevent the spread of the bacterium. It can also be prevented
by vaccination which can last for about 6 months.
Black death is preferred to be an effective biological weapon because:
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Easily spread by aerosol spray (i.e. easy to spread and use)
High death rate within a few days.
Vaccination is uncommon.
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Botulism
Botulism is a food poisoning caused by a neuraltoxin produced by the bacteria, Clostridium
botulinum. It is due to the direct ingestion of a toxin formed in contaminated food. Victims of
this disease will have blurred or double vision, general weakness, poor reflexes and difficulty
swallowing or breathing, which appears in 12-36 hours after ingestion. To cure the disease,
antitoxin or vaccination of botuninum immune globulin is given to the victims.
Botulism is used as biological weapon because:
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Easy to make.
Spread in different forms. e.g. in aerosol, in food and water, etc.
Quick effect.
Ricin
Ricin is a potent protein toxin derived from the beans of the castor
plant (Ricinus communis), which is fairly easily produced. When
inhaled as a small particle aerosol, this toxin may produce pathologic
changes within 8 hours and severe respiratory symptoms followed by
acute hypoxic respiratory failure in 36-72 hours. The victims will be
weakness, fever, cough, respiratory distress and finally death from
hypoxemia.
There is currently no vaccine or antitoxin available and management is supportive and should
include treatment for pulmonary edema. Gastric decontamination measures should be used if
ingested.
Ricin can be used as biological weapon because:
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Spread in different form. (e.g. poison of water and food stuff)
Easy to obtain and make.
No cure.
Tularemia
Tularemia, also known as rabbit fever, is a disease that caused by a bacterium, Francisella
tularemsis. This disease is named as rabbit is the species most often involved in disease outbreaks.
The infection can be by inoculation of the skin or mucous membranes with blood or tissue while
handling, dressing or skinning infected animals, contact with fluids from infected flies or ticks, the
bite of infected ticks, handling or eating insufficiently cooked rabbit, drinking contaminated water,
inhaling dust from contaminated soil, or handling contaminated pelts or paws of animals. It
cannot be spread from one person to another.
The symptoms may appear in 2-10 days. The victims will have skin lesion and swollen
glands. Ingestion of the organism may produce a throat infection, intestinal pain, diarrhea and
vomiting. Inhalation of the organism may produce a fever alone or combined with a pneumonia
like illness. The victims can take antibiotics to cure the disease, and one will develop a degree of
immunity against the disease.
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The tularemia can be used as biological weapons because:
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Spread in different form (e.g. in water and through air)
Fast effect (2-10 days)
Marburg Hemorrhagic Fever
Marburg hemorrhagic fever is a rare type of fever which affects both
humans and non-human primates. It is caused by a genetically unique
animal borne virus. The infection is by direct handling of infected
monkeys or contact with their fluids or cell cultures. Droplets of body
fluids, or direct contact with persons, equipment, or other objects
contaminated with infectious blood or tissues can cause the disease.
The victims will have fever, chills, headache and myalgia (肌肉痛) after 5 days of infection.
The victims then have maculopapular rash (疹), most prominent on the chest, back and stomach
may occur. Nausea, vomiting, chest pain, a sore throat, abdominal pain, and diarrhea may appear.
As there are many signs and symptoms which are similar to other infectious disease, it is difficult to
diagnosis. There is no cure currently but supportive therapy should be used.
Marburg Hemorrhagic Fever can be used as biological weapon because:
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No cure.
Difficult diagnosis.
Easy to spread.
Biological Weapons
References
General
http://www.ocean.ic.net/ftp/doc/disaster/bio/biowfaq.html
Anthrax
http://www.terrorismfiles.org/weapons/anthrax_biological_warfare_agent.html
http://www.aomc.org/ComDiseases/Anthrax.html
Small pox
http://www.hopkins-biodefense.org/pages/agents/agentsmallpox.html
http://www.bt.cdc.gov/agent/smallpox/overview/disease-facts.asp
Black death
http://www.insecta-inspecta.com/fleas/bdeath/Black.html
http://www.needham.k12.ma.us/pollard/student_projects/plague/
http://ponderosa-pine.uoregon.edu/students/Janis/menu.html
Botulism
http://www.ianr.unl.edu/pubs/foods/nf162.htm
Ricin
http://www.nbc-med.org/SiteContent/MedRef/OnlineRef/FieldManuals/medman/Ricin.htm
Tularemia
http://www.dhfs.state.wi.us/healthtips/BCD/Tularemia.htm
Marburg hemorrhagic fever
http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/marburg.htm
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