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Biological Terrorism Agents

What are biological terrorism agents?

Biological terrorism agents are bacteria or viruses that make poisons and cause infections. Some examples are:

  • anthrax
  • botulism
  • plague
  • smallpox
  • tularemia.

What is anthrax?

Anthrax is a type of bacteria that lives in the soil and forms spores. The bacteria and spores can infect animals and people. Anthrax infections can be fatal if they are not treated early with antibiotics.

You may get infected with anthrax if:

  • You handle infected animals, animal parts, or materials contaminated with the bacteria.
  • You breathe the bacteria or spores into your lungs.
  • You eat undercooked meat from infected animals.

Anthrax bacteria are common but anthrax infections are very rare in the US. Anthrax is not known to spread from person to person.

The 3 types of anthrax infections are:

  • Cutaneous (skin) anthrax

    Most anthrax infections happen when the bacteria enter a cut or scrape in the skin. Skin infection starts as a raised itchy bump that looks like an insect bite. In 1 to 2 days the bump becomes a blister and then a painless open sore. The sore is usually 1 to 3 cm (an inch or smaller) in diameter, with a black area in the center. Lymph glands near the sore may swell. Treatment with antibiotics usually cures the infection.

  • Inhalation anthrax

    If you breathe anthrax bacteria or spores into your lungs, symptoms of infection may start 1 to 6 days later. The first symptoms are like the symptoms of a cold or flu: fever, tiredness, and cough. The symptoms may get worse quickly. The infection can cause severe breathing problems and shock. Inhalation anthrax is often fatal if it is not treated before symptoms start.

  • Intestinal anthrax

    You can get an anthrax infection in your digestive system by eating contaminated meat. The first symptoms are nausea, loss of appetite, vomiting, and fever. You may have pain in your belly. As the symptoms get worse, you may vomit blood. You may have very bad diarrhea. Intestinal anthrax causes death in 25% to 60% of cases, even with treatment.

Being exposed to anthrax does not mean that you will be infected and get sick. For example, you could get anthrax spores in your nose but not in your lungs.

Anthrax is diagnosed from your history, physical exam, and lab tests of samples of blood, sputum, stool, or skin. If you have definitely been exposed to anthrax, you will need antibiotics. If there is a good chance you have been exposed, it may be recommended that you start treatment before the test results are in.

There is a vaccine that can help prevent anthrax infection, but it is not available for everyone. It is recommended only for:

  • people who work with animal hides or furs
  • people who work with animal products that have high rates of anthrax infection
  • animal doctors who treat animals in foreign countries
  • people who study anthrax in the lab
  • some people in the armed services.

If there is a threat of bioterrorism with anthrax, here are some things you can do to help keep from getting infected with anthrax:

  • Don’t handle suspicious letters, packages, or other objects.
  • Don’t eat meat that has not been cooked properly.

If you live or work where anthrax has been reported, call your healthcare provider or go to the emergency room if:

  • You have fever, chest pain, and muscle aches.
  • You have a suspicious skin sore.
  • You have suspicious cold or flulike symptoms or unexplained nausea, vomiting, and diarrhea.

What is botulism?

Like anthrax, botulism is caused by bacteria that live in the soil. The poison made by these bacteria causes paralysis. It is one of the deadliest substances known to man. Even a tiny amount can be fatal. Death usually occurs when the muscles needed for breathing become paralyzed by the poison.

Eating food that has botulism bacteria is the usual cause of infection. Poorly preserved canned foods are the most common example. However, you can also become infected or poisoned by breathing the bacteria or poison into your lungs, or by getting the bacteria in a wound.

The symptoms of botulism may start within a day or two after exposure to the bacteria. Sometimes symptoms may not appear for several days. The symptoms are:

  • blurred vision and problems focusing
  • trouble swallowing, speaking, or breathing
  • vomiting
  • weak muscles.

The diagnosis of botulism is made from your history and physical exam. Samples of blood or bowel movement may be tested in the lab.

The infection can be treated with a medicine called an antitoxin. People infected with botulism sometimes need a machine called a ventilator to help them breathe until they get better.

Botulism isn't contagious. A terrorist release of the poison in the air is dangerous only right at the time the poison is released. Chlorine can kill the bacteria that cause botulism. (Chlorine is added to most water supplies in the US.) If you think food may be contaminated, you can destroy the poison by boiling the food for 10 minutes. If you suspect that a surface is contaminated, it can be cleaned with soap and water or a bleach solution. The poison will not hurt your skin, but you can get infected if the bacteria enter your body through a wound.

Call your healthcare provider if you live or work in an area where botulism has been reported AND:

  • You start having muscle weakness, new constant blurry vision, and trouble swallowing, speaking, or breathing.

What is plague?

The bacteria that cause plague are usually spread by fleas that feed on infected rodents, such as rats. The fleas infect people by biting them. Plague that starts this way is called bubonic plague. However, the plague can also be spread through the air. If an infected person gets pneumonia from the plague, it is called pneumonic plague. Pneumonic plague can be spread from person to person by coughing, sneezing, or even just talking. Plague can be fatal if it is not treated early. There are usually 10 to 15 cases of plague in the US every year, primarily in the southwest where the flea carrier is the prairie dog.

The first signs of bubonic plague are fever, chills, weakness, and tender lymph nodes 2 to 10 days after a flea bite. Bubonic plague can spread to the blood, lungs, and nervous system.

The first signs of pneumonic plague are fever, chills, headache, weakness, and coughing with bloody or watery sputum. These symptoms usually start 1 to 6 days after exposure. The pneumonia gets worse over 2 to 4 days. Pneumonic plague can cause shock and death if it is not treated within 24 hours of the start of symptoms.

Plague is diagnosed from your history, physical exam, and lab tests of a sample of tissue from an infected lymph node.

When plague is treated early with antibiotics, the infection is usually not fatal.

Antibiotic treatment for 7 days can protect you if have had close contact with someone who has pneumonic plague. Researchers are working on developing a safe and effective vaccine for plague.

Call your healthcare provider if you live or work in an area where plague has been reported AND:

  • You have a fever.
  • You have swollen lymph nodes (also called swollen glands).
  • You have a new persistent cough with bloody or large amounts of sputum.
  • You have had close contact (within 6 feet, or 2 meters) with someone known to have untreated pneumonic plague.

What is smallpox?

Smallpox is caused by the variola virus. It is spread from person to person by droplets of saliva from coughing and sneezing. The virus causes fever and a rash. It kills about 1 of every 3 people who get the infection.

No smallpox infections have been reported anywhere in the world since 1977. Small amounts of the virus have been kept for research purposes, and there is a risk that smallpox could be used for biological terrorism.

Symptoms of smallpox start about 12 days after exposure. Some of the first symptoms are high fever, fatigue, headache, and backache. Two to four days later a rash appears. Blisters develop, which become scabs in 1 to 2 weeks. Smallpox is diagnosed from the symptoms, a physical exam, and lab tests of fluid samples from the mouth or blisters.

Because it is caused by a virus, smallpox cannot be treated with antibiotics. And no antiviral treatment is known to be effective against smallpox. IV fluids and antibiotics to prevent bacterial infections can help but will not cure the disease.

The smallpox vaccine was given to most people until 1972, when the US decided to stop routine smallpox vaccinations. The vaccine caused side effects and there was almost no risk of getting smallpox by that time. The US does have an emergency supply of smallpox vaccine. The smallpox vaccine can protect you even when it is given 2 to 4 days after exposure to the disease. It may prevent smallpox infection or it may make the illness less severe. Immunity to the infection weakens over time. If you got the smallpox vaccine before 1972, you are probably no longer protected against the disease.

Call your healthcare provider if you live or work in an area where smallpox has been reported AND:

  • You think you have been exposed to someone who has smallpox.
  • You have fever, chills, headache, nausea, vomiting, and severe muscle aches.
  • You start having blisters after 2 to 4 days after you think you were exposed.

What is tularemia?

Tularemia is caused by bacteria that spread to humans by the bite of a tick, fly, or mosquito. It can also be spread by contact with infected animals, such as rabbits or deer. You can also become infected by breathing in contaminated dust or air, drinking contaminated water, or eating the meat of an infected animal without cooking it well first. Tularemia is not known to spread from person to person.

The illness can affect the body in different ways. Symptoms start within a few days of exposure. Some of the symptoms are fever, chills, headache, nasal congestion, sore throat, cough, pain in your back or belly, stiff neck, skin ulcers, diarrhea, and vomiting. The diagnosis is based on the symptoms, history of possible exposure, and lab tests of samples of blood and sputum.

Tularemia can be treated with several common antibiotics. With treatment, the disease is usually not fatal.

A shot of an antibiotic given soon after exposure can prevent illness. An experimental vaccine to protect against tularemia has been developed but is not yet available.

If the bacteria that cause tularemia are on a surface or in water, they can be killed by chlorine.

Call your healthcare provider if you live or work in an area where tularemia has been reported AND:

  • You have unexplained muscle, abdominal, or back pain.
  • You have a fever that doesn't go away in 2 to 3 days.
  • You have cold symptoms that don’t get better in 7 to 10 days.

What are viral hemorrhagic fevers (VHFs)?

Viral hemorrhagic fevers (VHFs) are a group of viruses that could be used for bioterrorism. Examples of VHFs include:

  • Ebola virus
  • hantavirus
  • yellow fever
  • Lassa fever
  • Marburg virus.

Some types of hemorrhagic fever viruses can cause relatively mild, flulike illness. However, many of the viruses cause severe, life-threatening disease.

The viruses are carried by some types of animals, and they are usually found in the areas where these animals live. Most are in sub-Saharan Africa, but some of the viruses can be found in many parts of the world, including the US. Usually the infections are spread to humans by rodents such as rats and mice. They can also be spread by fleas and ticks. Some of the viruses can spread from person to person. These viruses could be used for bioterrorism if they were put into weapons or spread through the air.

Because people are usually infected with these illnesses in rural areas outside the US, a history of where you have traveled is important in the diagnosis. Cases of hantavirus have occurred mainly in the American Southwest after exposure to infected rodent droppings.

Infections with these viruses can cause many of the organs in the body to stop working right. The first signs and symptoms often include high fever, tiredness, dizziness, muscle aches, and weakness. People with severe cases of VHF often have bleeding under the skin, in internal organs, or from body openings such as the mouth, eyes, or ears. Severe infections may cause shock, coma, delirium, and seizures.

There is no specific treatment for any of the viral hemorrhagic fevers. If you have symptoms of viral hemorrhagic fever, see your healthcare provider right away. Supportive treatment will be given for the affected organs. For example, severe breathing problems will be treated with a ventilator machine to ensure regular breathing until you are able to breathe on your own again. Some antiviral medicines have been used, but this is still experimental.

What should I do if I think I may have been exposed to a biological terrorism agent?

It is important to remain calm but watchful. Most of the most dangerous biological terrorism agents act slowly. If they are found and treated early, they are usually not fatal. If you have been or are currently in an area where biological agents have been found AND you have suspicious symptoms, report them to your healthcare provider.

Developed by Tom Richards, MD, and RelayHealth.
Published by RelayHealth.
Last modified: 2011-06-28
Last reviewed: 2011-06-02
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
© 2011 RelayHealth and/or its affiliates. All rights reserved.
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