Bioterrorism

Bioterrorism is the intentional use of harmful biological, or living organisms or their toxic products to cause injury or death to people or animals.

What Is Bioterrorism?

Also known as biological warfare, bioterrorism is a form of warfare that uses specific microorganisms ^* , such as harmful bacteria and viruses, to cause illness or death deliberately in people or animals. When organisms are used in this way, they become weapons.

The History of Bioterrorism

The use of microorganisms to spread disease intentionally is not new to the twenty-first century. In 1346, it is believed that the Tartar army tried to capture the port city of Caffa on the Black Sea in the Crimea by catapulting bodies of plague (PLAYG) victims over the city walls. A plague epidemic ^* ensued, and Caffa surrendered. During the French and Indian Wars in the eighteenth century in North America, the British were rumored to have given blankets contaminated with smallpox to Native Americans, leading to an epidemic of the disease.

The Tartars and the British troops did not know that certain microorganisms cause disease. They knew only that disease was rumored to have spread from dead bodies or, in the case of smallpox, even from the blankets that touched victims. People were not aware that microorganisms are at the root of infectious disease until the latter part of the nineteenth century, when scientists began to understand the connection. In 1876, the German scientist Robert Koch had proved that anthrax (AN-thraks) bacteria cause anthrax. After World War II the United States and other nations experimented with harmful biological organisms and various methods of transmitting them. In 1972 the Biological Weapons Convention treaty was signed by more than 100 countries around the world, including the United States and the Soviet Union, to stop research and production of biological organisms as weapons of war.

It is likely that some countries in the world today—especially those harboring or supporting known terrorist groups—continue to manufacture and store stockpiles of dangerous microorganisms, such as those that cause anthrax. The use of bioterrorism to wage warfare is favored among terrorists or fringe groups because it requires few resources compared with traditional warfare and can potentially harm large numbers of people.

How Can Biological Agents Be Spread?

Deadly microorganisms (also known as biological agents or bioweapons) can be spread purposely through air or food and water supplies or by intentionally infecting someone with a highly contagious agent and letting that person circulate in a community, starting a massive wave of disease. But the handling and release of many of these organisms are dangerous and could be deadly for potential terrorists trying to use them.

Some organisms can be aerosolized (AIR-o-suh-lized), meaning that they are processed into the tiniest of particles, in a wet or dry form, that can be sprayed or released into the air so that large numbers of people can inhale them. Aerosolized organisms can be dispersed by aerosol containers, small crop-dusting planes, ventilation systems, or contamination of an object that can carry disease throughout a region, like the anthrax-tainted letters received by various government and media employees in the United States in late 2001.

Some harmful biological organisms become weakened, however, as they spread into water or food supplies, making them less likely to cause significant harm to anyone who comes into contact with them. For example, a person would have to inhale thousands of anthrax spores ^* to become sick. A terrorist group trying to use anthrax as a bioweapon would have to use a highly concentrated form to be able to harm large numbers of people via contaminated packages or envelopes.

What Are Potential Biological Agents?

The U.S. Centers for Disease Control and Prevention (CDC) separates biological organisms into categories according to their virulence (VEER-uh-lents), or ability to cause disease. The most virulent biological diseases are also the most likely to be used by terrorists. These diseases are anthrax, smallpox, plague, botulism (BOH-chu-lih-zum), and tularemia (too-lah-REE-me-uh).

Anthrax

Anthrax is caused by the bacterium Bacillus anthracis. The bacteria can form spores, which have a hard coating that allows them to survive in harsh environments. The spores are found naturally in soil and can infect grazing animals, most often livestock such as cattle, sheep, or horses. The disease is not contagious from person to person, and natural human infection is rare.

There are three types of anthrax, distinguished by the three different ways in which a person becomes infected: cutaneous (kyoo-TAY-nee-us) anthrax, which infects the skin; inhalation (in-huh-LAY-shun) anthrax, which results from breathing in large numbers of concentrated spores; and gastrointestinal ^* (gas-tro-in-TES-tih-nuhl) anthrax, which is caused by ingesting spores. Cutaneous anthrax causes brownish-black ulcers, or sores, that turn into scabs on the skin. Symptoms of inhalation anthrax include rapid onset of fever, chills, headache, nausea, and vomiting, with victims quickly experiencing difficulty in breathing. Gastrointestinal anthrax is very rare and causes severe abdominal ^* pain, diarrhea (dye-uh-REE-uh), and hemorrhaging ^* from the gastrointestinal tract.

All forms of anthrax can be treated with antibiotics if they are diagnosed early, but the inhalation and gastrointestinal types of anthrax are extremely deadly if left untreated. Even with treatment, patients with inhalation or gastrointestinal anthrax can die from the disease. There is an anthrax vaccine ^* , but it is given only to people in the military and people such as veterinarians who routinely handle livestock and are therefore more likely to come into contact with the natural form of the disease.

Smallpox

Smallpox is a deadly viral infection that is caused by the variola virus and is found only in humans. In the twentieth century smallpox claimed millions of lives, but in 1980 the World Health Organization (WHO) declared the disease to have been eradicated (eliminated) from the human population following an aggressive worldwide vaccination (vak-sih-NAY-shun) program. Routine vaccination against smallpox in the United States ended in 1972, and the last known natural case of smallpox was in 1977 in Somalia in Africa. Today there are two official facilities that store samples of the virus: the CDC in Atlanta, Georgia, and the Russian State Research Center of Virology and Biotechnology in Koltsovo.

Smallpox is the most contagious disease known and is transmitted through direct contact with the lesions ^* of an infected person, by inhaling infected droplets of moisture released into the air by coughing patients, and even by handling contaminated clothing that contains fluid from smallpox sores. The symptoms of smallpox are high fever, headache, backache, vomiting, and a painful rash of lesions that covers the face, arms, and body and often leaves scars. The disease is fatal in up to 30 percent of cases, and at this time there is no known medication that can cure smallpox. Vaccination given within 4 days of exposure to the virus sometimes can prevent smallpox or lessen its symptoms, including the rash.

The CDC keeps an emergency supply of smallpox vaccine in the event that bioterrorism attacks with smallpox occur in the United States. In 2002, some vaccine-making companies received approval from the CDC to make an additional supply of the vaccine, should it be needed on a more widespread basis.

In order to protect U.S. citizens against the threat of a bioterrorism attack, President George W. Bush announced in late 2002 that some members of the U.S. military will be vaccinated against smallpox and he called for health care workers to volunteer to receive the vaccine.

Plague

Plague, caused by the bacterium Yersinia pestis (yer-SIN-e-uh PES-tis), has been around for centuries. It can take three forms: bubonic (byoo-BAH-nik), septicemic (sep-tih-SEE-mik), and pneumonic (nu-MOH-nik). Bubonic plague, the most common form, involves the body's lymph nodes ^* ; septicemic plague enters the bloodstream, causing internal bleeding and shock ^* ; and pneumonic plague infects the respiratory tract ^* . The last form is potentially important in biological warfare because Yersinia pestis bacteria can remain alive in the air for up to an hour, making aerosolized transmission possible.

Yersinia pestis is found in rats and other rodents in all parts of the world, including the United States. Plague can spread from infected rats to humans by direct bites or from fleas. The pneumonic form of plague is the only kind that is contagious among humans; transmission takes place by being in close contact with someone who is coughing or sneezing. Symptoms of the plague include fever, chills, headache, abdominal pain, painful and swollen lymph nodes (called buboes, BYOO-boze), chest pain, coughing, bloody sputum ^* , and septic shock ^* . There is no vaccine available in the United States, but antibiotics can treat the disease successfully if it is diagnosed early.

Botulism

Botulism is caused by the toxin ^* produced by the bacterium Clostridium botulinum. The bacteria can be inhaled or swallowed, or they can enter the body through a wound, but the disease is not contagious from person to person. The toxin produced by the bacteria affects neurotransmitters ^* in the body, causing nerve damage and temporary paralysis ^* , including the muscles for speaking, swallowing, and breathing. Botulism can lead to respiratory failure ^* and even death. The bacterium and its toxin could be used to produce bioweapons. An antitoxin ^* against the Clostridium botulinum toxin is available from the CDC, but there is currently no vaccine available.

Tularemia

Tularemia is caused by the bacterium Francisella tularensis and is highly infectious. It occurs naturally in mice, rabbits, squirrels, and other small mammals. The disease is not contagious among humans, and human infection is rare. Tularemia can be transmitted through contact with infected animals or contaminated water or soil. The disease is potentially dangerous as a biological weapon, because even small numbers (less than 10 to 50) of the aerosolized bacteria can cause serious disease, such as life-threatening pneumonia ^* . Symptoms include fever, chills, headache, cough, and extreme tiredness. Patients also may have painful ulcers on the skin; swollen, painful eyes; and abdominal pain. Early treatment with antibiotics may prevent or limit the severity of the disease.

What Can We Do to Protect Ourselves?

Following the terrorist incidents and anthrax scare of fall 2001, the U.S. government proposed that billions of dollars be channeled into improving national resources that provide protection against and treatment of the effects of bioweapons. The Office of Homeland Security was formed in late 2001 to oversee the government's preparation for and defense against future acts or threats of bioterrorism that might occur in the United States. The government has authorized an increase in federal stockpiles of antibiotics to treat anthrax, plague, tularemia, and other potential bioweapons, as well as the production of additional supplies of smallpox vaccine. Research continues in the development of better medical treatment and the creation of vaccines for protection against biological agents. Medical professionals and emergency response teams are being trained to diagnose the diseases and respond quickly to the epidemics that could result from bioterrorism. Experts advise that people not stockpile antibiotics out of fear of possible biological warfare, because they could end up using the medicine incorrectly or in the wrong situation. Stockpiling also can lead to a shortage of certain antibiotics and make them unavailable to people who truly need them to treat other diseases.