Anthrax, a biological or psychological weapon?

Be careful with your letters and mailbox!...

After the news of the recent anthrax cases in USA spread, the scare of bioterrorism was ignited. Even in Thailand, a suspected letter with white powder found in Cholburi province was sent to test for anthrax spore.

What makes Anthrax such an effective means of spreading Terror? What is biological weapon?  What is anthrax? What precautions should you take? and What to do in case you suspect that you are infected?

What is biological weapon?

Biological weapons are made from microorganism, its spore or its toxin such as some bacteria and viruses which cause the violent infectious diseases or acute syndromes. Weight-for-weight, they are hundreds to thousands of times more potent than a chemical weapon, according to the Center for Defense and International Security Studies in the UK. Though Anthrax is best known for making newspaper headlines other dangerous agents like botulism, smallpox, plague, tularemia and viral hemorrhagic fevers exists. It is interesting to note that most of these so called biological weapons are diseases known to medical experts for years. Cures and vaccinations have been availible in reputed hospitals worldwise. When used as Biological weapons the terrorists aim to spread the disease to the extent that medical facilities cannot cope with the outbreak or generate public hysteria of a possible outbreak.

Source: Center for Disease Control and Prevention (CDC)

The Public Health Minister Sudarat Keyuraphan assured the public that Thailand was well prepared, though it was believed the chance of a biological or chemical attack was remote.  She said that ``There's no need for Thai people to worry since Thailand is not involved in the US-Afghanistan conflict''.

The Government Pharmaceutical Organization has been ordered to produce antibiotics for the general public in the event of an anthrax attack.  Deputy Defense Minister Gen Yuthasak Sasiprapha, meanwhile, assured that the ministry was well-equipped with protective gear, such as masks and protective suits for germ detectors in case biological agents were found.  However people who find any suspicious objects should report directly to the provincial health offices or other provincial authorities so the matter may be pursued.

 

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What is anthrax?
Anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis.  The spore produces a toxin that can be fatal.  It is commonly found in Thailand and the hospital had gained expertise from years of administering treatment. There were several ways of contracting anthrax, including cutaneous (Skin) exposure, intestinal exposure and through inhalation. Inhalation is the most dangerous form and can result in the death of the victim if medical attention is not sought on time.  Normally the disease cannot be transmitted between people and is curable by antibiotics.  Thai medical experts are familiar with the disease, and last year only one person died of anthrax because he did not reach the doctor in time.

Symptoms: Usually symptoms appear within seven days. Inhalation anthrax infection can start out like a common cold before acute symptoms such as severe breathing problems and shock. Skin infection can look like an insect bite at first but within days develops into an ulcer with a characteristic black center. Infection by consuming contaminated food is characterized by inflammation of the intestinal tract, leading to vomiting of blood and severe diarrhea.

Treatment: Antibiotics, including penicillin. A delay in the use of antibiotics may lessen chances for survival.

Prevention: Vaccination

Reference: Inglesby TV, et al.  Anthrax as a biological weapon; Medical and Public Health Management

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Botulism

Botulism toxin or botulinus poison is the most potent lethal substance known to man.  It is made by the bacterium Clostridium botulinum.  The bacterium is an anaerobic (not require oxygen), spore-forming organism which is widely distributed in soils.  It grows readily under anaerobic conditions (oxygen free condition) in improperly sterilized preserved foods which have a near-neutral or slightly alkaline reaction.  In adequately processed home-canned foods are most often the cause of botulism, but preserved meats and fishes also are causes.  The ingestion of even minute quantities will result in a severe syndrome which may be fatal within 2-10 days or within 24 hours in extreme exposure.  Botulism toxin can be inhaled or ingested via contaminated food or water.

Symptoms:  Headache, nausea, double vision, slurred speech, dry mouth and muscle weakness or paralysis, which also starts at the top of the body and works its way down. Symptoms begin from six hours up to two weeks after exposure. Death can be caused by paralysis of the breathing muscles within 24 hours.

Treatment: Treatment is primary supportive in addition to the administration of botulism anti-toxin.

Prevention: Vaccination 

Reference: Arnon SS, et al.  Botulinum Toxin as a biological weapon; Medical and Public Health Management.  JAMA 2001; 285(8): 1059-81.

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Smallpox
This acute viral disease caused by the variola virus once claimed a high mortality rate, but was officially announced as globally eradicated in 1979.  Smallpox probably was first used as a biological weapon during the French and Indian Wars (1754-1767) by British forces in North America.  Smallpox comes in two forms: variola minor or the more deadly variola major.  

Symptoms: The incubation period is about 7-17 days following exposure.  Symptoms include fever, fatigue, headache and backache followed by a rash.  The eruption of a widespread rash that is raised, vesicular and finally pustularThe eruption follows a set pattern of dissemination, commencing on the head and face.  When the final stage is passed scars (pockmarks) are left to disfigure the skin.  Patients can die within the first two weeks of the illness.

Treatment: No proven treatment at this time.

Prevention: Vaccination.

Reference:  Henderson DA, et al.  Smallpox as a biological weapon; Medical and Public Health Management.  JAMA 1999; 281(22): 2127-37

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Plaque
The plaque is also known as pest and pestis. It is an infectious disease due to a bacteria called Yersinia Pestis. Yersinia is found in rodents and their fleas.  Fleas function as the prime vectors carrying the bacteria from one species to another. The fleas bite the rodents infected with Y. pestis and then they bite people and so transmit the disease to them.  The plaque bacterium could be disseminated by aerosol, resulting in the pneumonic form with the potential for secondary spread of cases through respiratory droplets of those infected. 

Symptoms: Within 1 to 6 days after exposure, the first signs of illness are fever, cough, headache, weakness, chest pain and cough with bloody phlegm like severe pneumonia symptoms, which can lead to shock and death within 2 to 4 days.

Treatment: Antibiotics within 24 hours of first symptoms.

Prevention: The US-licensed vaccine for prevention of plaque used to be produced and was discontinued by its manufacturers in 1999.  It is no longer available while the future plan and production are unclear.  The vaccine is made from the formaldehyde-killed whole bacteria.  It can prevent bubonic plaque, but can not prevent primary pneumonic plaque.  The additional research to find the best vaccine for prevention of primary pneumonia plaque is continued.

Reference: Inglesby TV, et al.  Plaque as a biological weapon; Medical and Public Health Management.  JAMA 2000; 283(17): 2281-90.

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Tularemia

Francisella tularensis is the causative agent of tularemia.  It is one of the most infectious pathogenic bacteria known.  Inhalation of as few as 10 organisms can cause death.  Humans become infected through bites by infected insects, contact with contaminated water or food, and inhalation of infective aerosols and can develop severe and sometimes fatal illness. The disease however is not be transmitted thru contact with imfected persons.

Symptoms: Earlier symptoms of infection by aerosol could be similar to those of influenza or a typical pneumonia.  The symptoms can occur within a few days or as long as two weeks after exposure.  Without treatment, the patient experiences progressive respiratory failure, shock, and death.

Treatment: Antibiotics

Prevention: Vaccination

Reference: Dennis DT, et al.  Tularemia as a biological weapon; Medical and Public Health Management.  JAMA 2001; 285(21): 2763-73.

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Viral Hemorrhagic Fevers (VHF)
The term viral hemorrhagic fevers (VHF) refers to a group of illnesses caused by several distinct families of viruses. While some of these viruses cause relatively mild illnesses, others cause severe, life- threatening ones, such as Ebola.
  Many VHF viruses are known to naturally reside in an animal or insect host, however the hosts of some VHF viruses remain unknown, including that of Ebola and Marburg viruses. Some VHF viruses can be transmitted by the body fluids of infected people.

Symptoms: Reactions vary depending on the type of VHF, but symptoms often include fever, fatigue, dizziness, muscle aches and exhaustion. Severe cases cause bleeding under the skin and in internal organs. Some types of VHF cause kidney failure.

Treatment: Generally there are no treatments other than supportive therapy for VHFs.

Prevention: Vaccines are available for only two VHFs: yellow fever and Argentine hemorrhagic fever

Reference: CDC (Centers for Diseases Control and Prevention)

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