Biological warfare

Biological warfare is the use of living organisms (e.g., bacteria , virus ) or biochemical agents (e.g., chemical neurotoxins) as strategic military weapons to cause harm in humans, animals, or plants. In contrast to bioterrorism , biological warfare is considered the governmentsanctioned use of biological weapons to attack a clearly defined military force or civilian population. These agents can be classified into six distinct groups; bacteria, viruses, rickettsiae, chlamydia, fungi , and biological toxins.

Bacteria (by itself or genetically engineered) can be used to produce disease that often can be treated with antibiotics . These are small organisms that can be easily grown on solid supports or liquid media. Viruses, however, require a living host in which to reproduce and are dependent on the cells they infect. Viruses sometimes can be destroyed using antiviral compounds, however, there is a limited supply of these compounds and only a few types available. Rickettsiae are organisms with similar characteristics common to bacteria, as they are susceptible to antibiotics, require oxygen , and have cell membranes. Rickettsiae are also similar to viruses in that they require a host to grow and reproduce. Chlamydia are parasites that cannot produce their own energy sources. Fungi can live without oxygen, are non-photosynthetic species , utilize decaying vegetable matter as their food source, and form spores. Toxins can be synthetic (chemical agents) or derived from poisonous substances produced by living plants, animals, or microorganisms . Toxins have an important advantage over pathogens as they are not alive and, therefore, they are more stable and easier to produce and distribute.

The degree at which these biological weapons become threatening involves several characteristics such as the level of infectiousness, toxicity, virulence, pathogenicity (ability to cause infectious disease), stability, and how easily they are transmitted from one species to the next.

Historical perspective of biological warfare

Biological weapons have been used as part of an arsenal during warfare for centuries. For example, ancient battle records suggest that diseased human remains and cattle that had died of microbial diseases were used to poison wells. In the spring of 1346, after a Mongol army attempted an overtake of the Crimean city of Caffa for three years without success, the Mongols gathered a number of their own people who had died of the plague, laid them on their catapults, and hurled them into the town. Eventually, the plague spread through Caffa causing residents to flee. It is quite possible that the successful conquest of the town by the Mongols may have resulted in the most damaging attack using biological weapons in world history. In the 1760s, a rebellion among Native Americans was countered when Lord Jeffrey Amherst, then commander-in-chief of British forces, suggested grinding pox scabs (pustule scabs) into blankets intended for distribution to members of an Ohio tribe. The disease broke out among the Native Americans, ending the rebellion.

During the twentieth century, a trend of designer biological weapons targeted for larger, more defined military objectives became more prevalent. Research projects aimed at developing anthrax-based biological weapon programs during World War II were initiated by Canada, the United States, and Britain. Britain produced anthrax-based weapons at the United Kingdom Chemical and Biological Defense Establishment at the Porton Down facility that were intended to be dropped on Germany to infect their food supply (reportedly, they were never used). Prisoners in Nazi Germany concentration camps were infected with pathogens, such as hepatitis A, Plasmodium falciparum, as well as other types of a bacteria for unclear research objectives. Countries such as Japan also conducted extensive biological weapons research during World War II while occupying part of China. Prisoners were infected with a variety of bacterial pathogens, including Neisseria meningitis, Bacillus anthracis (anthrax ), and Yersinia pestis. It has been estimated that over 10,000 prisoners died as a result of either infection or execution following infection. In addition, biological agents contaminated the food and water supply. It is also thought that approximately 15 million potentially plague-infected fleas were released from Japanese aircrafts, affecting many Chinese cities with an estimated 10,000 illnesses and 1,700 deaths.

The development of airborne biological weapons make biological warfare particularly dangerous. For example, British open-air testing of anthrax weapons in 1941 on Gruinard Island in Scotland rendered the island uninhabitable for five decades. The United States Army conducted a study in 1951–52 called Operation Sea Spray to study how wind currents might effect the dispersion of bioagents. As part of the project design, balloons were filled with Serratia marcescens (then thought to be relatively harmless) and exploded over San Francisco. Reportedly, there was a corresponding significant increase in the number of pneumonia and urinary tract infections. In 1979, an accidental release of anthrax spores (approximately a gram for several minutes) at a bioweapons facility near the Russian city of Sverdlovsk, infected 77 and killed 66 people that were approximately 2.5 mi (4 km) downwind of the facility. Sheep and cattle up to 31 mi (50 km) downwind also became ill. From these events, anthrax is considered one of the most deadly biological weapons. A dose of 10,000 spores, or one millionth of a gram, is fatal within days after exposure in 90–100% of the population. According to the U.S. Congress Office of Technology Assessment, an aircraft that drops 220 lb (100 kg) of anthrax over a city under normal weather conditions would be lethal for approximately one to three million people. Skin contact with spores can also produce a less lethal, but dangerous cutaneous anthrax infection. Without antibiotic treatment, the mortality rate for cutaneous anthrax is 10–20% and with treatment, the mortality rate falls to less than 1%.

The first diplomatic effort to reduce biological warfare was initiated by the international community in 1925 and called the Geneva Protocol, a treaty prohibiting the development and use of any form of biological weapon in war. During the 1950s and 1960s, the United States constructed research facilities to develop antisera, vaccines, and equipment for protection against a possible biological attack as well as the use of microorganisms as offensive weapons. Since then, other initiatives to ban the use of biological warfare and/or destroy the stockpiles of biological weapons have been attempted. Despite the international prohibitions, the existence of biological weapons remains an impending and growing threat. In 1972, 87 nations, including the United States, signed the Biological Weapons Convention Treaty, which banned the development, testing, and storage of such weapons. For a time, it appeared that the world agreed to ban biological weapons. By the 1980s, the political mood had changed. In 1982, President Ronald Reagan declared that world politics justified research on biological and chemical weapons and that the United States would return to a more ambitious program.

Over the last decade, an emphasis on the development of chemical toxins and the development of genetically engineered biological weapons emerged due to international political instability in several countries, along with the uprising of extremist groups and disestablishmentarianism in the Middle East. During the Persian Gulf War, U.S. troops were exposed to an uncertain source of biological weapons leading to what are called the Gulf War Illnesses. In Iraq, five hidden laboratories were discovered that were designed to refine and stockpile several biological weapons including anthrax, botulism , and gas gangrene bacteria. In 1997, Secretary of Defense William Cohen pinpointed Libya, Iraq, Syria, and Iran as countries that were launching aggressive biological weapon development programs. In 1998, several scientists that were part of the former Soviet Union's biological and chemical weapons programs were reported to have been recruited to develop biological warfare in Libya. Not long after the terrorist attacks on the U.S. World Trade Center and Pentagon in 2001, the postal service was used by terrorists (possibly unrelated to World Trade Center and Pentagon attacks) to deliver anthrax by mail to several locations within the U.S. On October 4, 2001, a 63-year-old man was reported to have contracted the first known intentionally inflicted case of inhalation anthrax in the U.S. By the time the outbreak was contained, the U.S. Centers for Disease Control reported 23 cases of inhaled or cutaneous anthrax (19 confirmed, 4 suspected), including five deaths.

Genetically engineered weapons and other biological weapons

Since about 1960, the development of genetic engineering has greatly expanded the possibilities of biological warfare. Genetic engineering is the process by which an organism's genetic properties are manipulated so that they acquire desired characteristics. In the case of biological warfare, the desired characteristics are harmful to mankind. Several issues arise when tampering with the genetic makeup of microorganisms such as the development of new diseases for which there is no treatment available for either opponent. Genetic engineering can also be applied for the purposes of making existing pathogens more pathogenic (disease-causing).

Other known biological agents that are considered biological weapons and might be used during biological warfare are botulism, brucellosis , Q fever, smallpox, saxitoxin, ebola hemorrhagic fever, tularemia, and staphylococcus enterotoxin.

Like most potential biological weapons, brucellosis occurs naturally among domestic and wild animals. It is spread by one of three varieties of the Brucella bacterium. It is seldom fatal, but causes a long-term, debilitating illness characterized by fever, loss of weight, general lassitude, and depression . Brucellosis is a biological weapon that does not kill people, but renders them so ill that they are unable to fight effectively. The disease can be treated with tetracycline.

Q fever is a biological agent that is not particularly harmful but is highly infectious. It is caused by a bacterial strain of the rickettsial organism Coxiella burnetii and produces headache, fever, chills, sweats, and a loss of appetite. Scientists believe that the condition is often mistaken for the flu. Like brucellosis, the value of Q fever is not in its toxicity, but in its ability to be easily spread. No more than a dozen microbes are needed to initiate an infection. It represents a particularly noxious biological weapon in its potential to be modified to cause disease or death.

From time to time, coastal waters in various parts of the world develop a reddish tinge because of a unicellular organisms called dinoflagellates. These so-called red tides are a warning that seafood from these waters are potentially unsafe. The dinoflagellates release a variety of toxins including saxitoxin. Some of these toxins quickly cause a type of paralysis that can cause death in humans in less than an hour. U.S. scientists prepared and tested shellfish toxins, including saxitoxin, for possible use as a biological weapon after World War II.

Many forms of Staphylococcus exist, some harmless and some quite dangerous. They are often responsible for specific forms of food poisoning and, in rare instances, exposure to these microorganisms can lead to toxic shock syndrome within hours. A person infected with Staphylococcus contaminated food experiences severe nausea, vomiting, diarrhea, and is essentially incapacitated for two or three days. Staphylococcus has a practical advantage in that it can be dried and stored for up to a year without losing its toxicity.

Tularemia is a plague-like disease caused by the bacterium Francisella tularensis. After an incubation period of about a week, a person infected with the bacterium begins to develop a fever accompanied by chills and headaches. If the bacterium is inhaled, symptoms also include chest pain and difficulty in breathing. The death rate is relatively low when exposure occurs through the skin, but much higher when inhaled. Delivery of a genetically modified form of the bacteria by aerosolization would cause a disease that is expected to have a case fatality rate which may be higher compared to the 5–10% seen when disease is acquired naturally.

See also Anthrax; Poisons and toxins.

Resources

books

Frist, William. When Every Moment Counts: What You Need toKnow About Bioterrorism from the Senate's Only Doctor. Lanham, MD: Rowman and Littlefield, 2002.

McCuen, Gary E. Poison in the Wind: The Spread of Chemical and Biological Weapons. Hudson: GEM Publications, Inc., 1992.

Tucker, Jonathan B. Scourge: The Once and Future Threat ofSmallpox. New York: Atlantic Monthly Publishers, 2001.

periodicals

Drotman, D. Peter, et al. "Bioterrorism-Related Anthrax." Emerging Infectious Diseases 8, no. 10 (October, 2002).

Inglesby, T.V., D.T. Dennis, D.A. Henderson, et al., for the Working Group on Civilian Biodefense. "Plague as a Biological Weapon: Medical and Public Health Management." Journal of the American Medical Association 283 (2000): 2281–90.

other

United States Centers for Disease Control. "Bioterrorism and Public Health Preparedness." [cited October 20, 2002]. <http://www.cdc.gov/od/oc/media/presskit/bio.htm>.

Brian R. Cobb

KEY TERMS

Epidemic

—A situation in which a particular infection is experienced by a very large percentage of the people in a given community within a given time frame.

Microorganism

—An organism so small that it can be seen only with the aid of a microscope.

Pathogen

—Any organism capable of causing a disease.

Plague

—A highly contagious disease that spreads rapidly through a population.

Toxin

—A poisonous substance.

Biological warfare

Resources

Biological warfare, as defined by the United Nations, is the use of any living organism (e.g., bacterium, virus) or an infective component (e.g., toxin), to cause disease or death in humans, animals, or plants. In contrast to bioterrorism, biological warfare is defined as the “state-sanctioned” use of biological weapons on an opposing military force or civilian population.

Biological weapons include viruses, bacteria, rickettsia, and biological toxins. Of particular concern are genetically altered microorganisms, whose effect can be made to be group-specific. In other words, persons with particular traits are susceptible to these microorganisms.

The use of biological weapons by armies has been a reality for centuries. For example, in ancient records of battles exist the documented use of diseased bodies and cattle that had died of microbial diseases to poison wells. There are even records that infected bodies or carcasses were catapulted into cities under siege.

In the earliest years of the twentieth century, however, weapons of biological warfare were specifically developed by modern methods, refined, and stockpiled by various governments.

During World War I, Germany developed a biological warfare program based on the anthrax bacillus (Bacillus anthracis ) and a strain of Pseudomonas known as Burkholderia mallei. The latter is also the cause of Glanders disease in cattle.

Allied efforts in Canada, the United States, and Britain to develop anthrax-based weapons were also active in World War II. During World War II, Britain actually produced five million anthrax cakes at the U.K. Chemical and Biological Defense Establishment at Porton Down facility that were intended to be dropped on Germany to infect the food chain. The weapons were never used. Against their will, prisoners in German Nazi concentration camps were maliciously infected with pathogens, such as hepatitis A, Plasmodia spp., and two types of Rickettsia bacteria, during studies allegedly designed to develop vaccines and antibacterial drugs.

Japan also conducted extensive biological weapon research during World War II in occupied Manchuria, China. Unwilling prisoners were infected with a variety of pathogens, including Neisseria meningitis, Bacillus anthracis, Shigella spp., and Yersinia pestis. It has been estimated that over 10, 000 prisoners died as a result of either infection or execution following infection. In addition, biological agents contaminated the water supply and some food items, and an estimated 15 million potentially plague-infected fleas were released from aircraft, affecting many Chinese cities. However, as the Japanese military found out, biological weapons have fundamental disadvantages: they are unpredictable and difficult to control. After infectious agents were let loose in China by the Japanese, approximately 10, 000 illnesses and 1, 700 deaths were estimated to have occurred among Japanese troops.

A particularly relevant example of a microorganism used in biological warfare is Bacillus anthracis. This bacterium causes anthrax. Bacillus anthracis can live as a vegetative cell, growing and dividing as bacteria normally do. The organism has also evolved the ability to withstand potentially lethal environmental conditions by forming a near-dormant, highly resistant form known as a spore. The spore is designed to hibernate until conditions are conducive for growth

KEY TERMS

Epidemic— A situation in which a particular infection is experienced by a very large percentage of the people in a given community within a given time frame.

Microorganism— An organism so small that it can be seen only with the aid of a microscope.

Pathogen— Any organism capable of causing a disease.

Plague— A highly contagious disease that spreads rapidly through a population.

Toxin— A poisonous substance.

and reproduction. Then, the spore resuscitates and active metabolic life resumes. The spore form can be easily inhaled to produce a highly lethal inhalation anthrax. The spores quickly and easily resuscitate in the warm and humid conditions of the lung. Contact with spores can also produce a less lethal but dangerous cutaneous anthrax infection.

One of the attractive aspects of anthrax as a weapon of biological warfare is its ability to be dispersed over the enemy by air. Other biological weapons also have this capacity. The dangers of an airborne release of bioweapons are well documented. British open-air testing of anthrax weapons in 1941 on Gruinard Island in Scotland rendered the island inhabitable for five decades. The United States Army conducted a study in 1951-52 called “Operation Sea Spray” to study wind currents that might carry biological weapons. As part of the project design, balloons were filled with Serratia marcescens (then thought to be harmless) and exploded over San Francisco, California. Shortly thereafter, there was a corresponding dramatic increase in reported pneumonia and urinary tract infections. And, in 1979, an accidental release of anthrax spores, a gram at most and only for several minutes, occurred at a bioweapons facility near the Russian city of Sverdlovsk. At least 77 people were sickened and 66 died. All the affected were some 2.5 miles (4 km) downwind of the facility. Sheep and cattle up to 31 miles (50 km) downwind became ill.

The first diplomatic effort to limit biological warfare was the Geneva Protocol for the Prohibition of the Use in War of Asphyxiating, Poisonous or Other Gases, and of Bacteriological Methods of Warfare. This treaty, ratified in 1925, prohibited the use of biological weapons. The treaty has not been effective. For example, during the “Cold War” between the United States and the then Soviet Union in the 1950s and 1960s, the United States constructed research facilities to develop antisera, vaccines, and equipment for protection against a possible biological attack. As well, the use of microorganisms as offensive weapons was actively investigated.

See also Anthrax; Poisons and toxins.

Resources

BOOKS

Frist, William. When Every Moment Counts: What You Need to Know About Bioterrorism from the Senate’s Only Doctor. Lanham, MD: Rowman and Littlefield, 2002.

McCuen, Gary E. Poison in the Wind: The Spread of Chemical and Biological Weapons. Hudson: GEM Publications, Inc., 1992.

Tucker, Jonathan B. Scourge: The Once and Future Threat of Smallpox. New York: Atlantic Monthly Publishers, 2001.

PERIODICALS

Drotman, D. Peter, et al. “Bioterrorism-Related Anthrax.” Emerging Infectious Diseases 8, no. 10 (October, 2002).

OTHER

United States Centers for Disease Control. “Bioterrorism and Public Health Preparedness” <http://www.cdc.gov/od/oc/media/presskit/bio.htm> (accessed October 18, 2006).

Brian R. Cobb

Biological Warfare

█ JUDYTH SASSOON

Biological warfare, as defined by the United Nations, is the use of any living organism (e.g. bacterium, virus) or an infective component (e.g., toxin), to cause disease or death in humans, animals, or plants. In contrast to bioterrorism, biological warfare is defined as the "statesanctioned" use of biological weapons on an opposing military force or civilian population. Biological weapons include pathogenic viruses, bacteria, and biological toxins. Of particular concern are genetically altered microorganisms, which are engineered to target a specific group of people.

Early History of Biological Warfare

Examples of the use of biological weapons exist in ancient records. In the sixth century b.c., Assyrians poisoned enemy wells with ergot, a toxin derived from mold that grows on rye. Other records of battles document the use of diseased corpses to poison wells. In 1346, plague-infected corpses and carcasses were catapulted into Kaffa, a city in current day Crimea, by the Tartar army. The epidemic that resulted may have eventually led to the great Black Plague that afflicted Europe. In 1710, the Russian army used a similar military strategy when it invaded Sweden. The Spanish are reported to have contaminated French wine with blood taken from people suffering from

leprosy in the mid-1400s. In the seventeenth century, a Polish general filled artillery shells with the saliva from rabid dogs.

Smallpox was used as a biological weapon several times during the colonization of the Americas. The Spanish explorer Pizarro gave blankets infested with the virus to natives in South America in the fifteenth century. Sir Jeffery Amherst presented blankets contaminated with the smallpox virus to native Americans during the French and Indian war between 1754 and 1767. The epidemic that followed resulted in the surrender of a strategic fort to the English. A Southern doctor is reported to have sold clothing contaminated with smallpox to the Union Army during the Civil War.

Modern History of Biological Warfare

During the twentieth century, modern scientific methods led to the development, refinement, and stockpiling of weapons of biological warfare by governments throughout the world. During World War I, Germany developed a biological warfare program based on the bacterium Bacillus anthracis and a strain of Pseudomonas known as Burkholderia mallei, which causes glanders disease in cattle. Dr. Anton Dilger, a German agent living in Washington D.C., reportedly grew anthrax and glanders bacteria in his home and then inoculated thousands of horses and cattle that were shipped to Allied troops in Europe. Many of the animals perished and hundreds of the troops exposed to these animals were secondarily infected by the diseases.

During World War II, prisoners in German Nazi concentration camps were infected with pathogens, such as Hepatitis A, Plasmodia spp., and two types of Rickettsia bacteria, during studies allegedly designed to develop vaccines and antibacterial drugs. A large reservoir in Bohemia was poisoned with sewage by the German army in 1945.

Between 1918 and 1945, the Japanese government conducted extensive biological weapon research at Unit 731 in occupied Manchuria, China. Prisoners of war were infected with a variety of pathogens, including Neisseria meningitis (meningitis), Bacillus anthracis (anthrax), Shigella spp. (shigellosis), and Yersinia pestis (black plague). Estimates are that over 3,000 prisoners died as a result of infection by these biological pathogens or execution following such infections. In 1941, the Japanese released an estimated 150 million potentially plague-infected fleas from aircraft over cities in China and Manchuria. After these infectious agents were released, outbreaks of plague occurred in many Chinese villages. In addition, approximately 10,000 illnesses and 1,700 deaths occurred among Japanese troops.

Driven by reports of Japanese and German programs to develop biological weapons, the Allies embarked on vigorous efforts to develop their own biological weapons during World War II. Britain produced five million anthrax cakes at the UK Chemical and Biological Defense Establishment at Porton Down with the intent of dropping them on Germany to infect the food chain. These weapons were never used. British open-air testing of anthrax weapons in 1941 on Gruinard Island in Scotland rendered the island inhabitable for five decades.

The United States government's biological warfare facility was headquartered at Fort Detrick in Maryland beginning in 1942. Weapons were also tested and produced in Colorado, Arkansas and Utah. Many different agents were studied including the bacteria that cause anthrax, plague, botulism, Q fever, and staphylococcal infections. Several viruses were also included in the research. The U.S. Army conducted a study in 1951–1952 called "Operation Sea Spray" to study wind currents that might carry biological weapons. As part of the project design, balloons were filled with Serratia marcescens (then thought to be harmless, but easily identifiable) and exploded over San Francisco. Shortly thereafter, there was a corresponding dramatic increase in reported pneumonia and urinary tract infections in the region.

The former Soviet Union was implicated in several incidents involving the development and release of biological agents. In 1979, an accidental release of a small amount of anthrax spores occurred at a bioweapons facility near the Soviet city of Sverdlovsk. At least 77 people were sickened and 66 died. All the affected people were some 4 kilometers downwind of the facility. Sheep and cattle up to 50 kilometers downwind became ill. Immediately following the incident, the Soviet government declared that the cause of the illnesses was contaminated meat. However, in 1992 Russian President Boris Yeltsin took responsibility, stating that the accident was the result of military research at the microbiology facility. Between 1975 and 1983, Soviet forces allegedly used "yellow rain" in military operations in Laos, Cambodia and Afghanistan. This substance, T2 toxin or trocothecene mycotoxin, is derived from the Fusarium fungi and is extremely damaging to the intestinal tract. The Soviet government has denied the use of T2 toxins, claiming that the yellow rain was the result of defecating bees.

In 1991, the Iraqi government admitted the existence of a biological weapons program within their military. They built bombs containing the botulinum toxin, anthrax and aflatoxins. Iraqi scientists also studied the uses of wheat cover smut, ricin and the toxins produced by Clostridium perfringens for biological weapons.

Diplomacy and biological warfare. The first diplomatic effort to limit biological warfare was the Geneva Protocol for the Prohibition of the Use in War of Asphyxiating, Poisonous or Other Gases, and of Bacteriological Methods of Warfare. This treaty, ratified in 1925, prohibited the use of biological weapons; however, it was not effective as Germany, the United States, Britain, and the Soviet Union all had biological weapons programs up to the 1960s. More than 140 countries, including the United States, signed the Convention on the Prohibition of the Development Production, and the Stockpiling of Bacteriological (Biological) and Toxin Weapons and on Their Destruction, also called the Biological Weapons Convention (BWC) in 1972, with limited success. Although the United States formally stopped biological weapons research in 1969 (by executive order of then President Richard M. Nixon), the Soviet Union carried on biological weapons research until its demise. Despite being a signator to the BWC, the Iraqi government allegedly continued its buildup of biological weapons into the twenty-first century.

Following the Iraqi war, however, anticipated stockpiles of biological weapons were not immediately found.

█ FURTHER READING:

ELECTRONIC:

Rhode Island Department of Health: Bioterrorism Preparedness Program "History of Biological Warfare and Current Threat" <http://www.healthri.org/environment/biot/history.htm> (March 12, 2003).

Arizona Department of Health Services: Epidemiology and Surveillance "History of Biowarfare and Bioterrorism" <http://www.hs.state.az.us/phs/edc/edrp/es/bthistor2.htm> (March 12, 2003).

SEE ALSO

Anthrax Weaponization
Biological and Toxin Weapons Convention
Bioterrorism
Chemical Warfare
Infectious Disease, Threats to Security
Viral Biology
Weapons of Mass Destruction

Biological warfare

Biological warfare (previously called germ warfare) is the use of diseasecausing microorganisms as military weapons. One of the earliest recorded uses of biological weapons occurred in the fourteenth century. Invading Asian armies used a device called a catapult to hurl bodies of plague (a deadly, highly contagious disease caused by a bacterium) victims over city walls to infect the resisting townspeople. It is thought that this practice resulted in the spread of the Black Death throughout Europe, killing millions of people in four years.

Toward the end of the French and Indian Wars in North America (1689–1763), a British military officer is said to have given blankets infected with smallpox germs to a tribe of Native Americans, resulting in their infection with the often fatal disease.

In more modern times, an outbreak of inhalation anthrax (a disease caused by inhaling the spores of the anthrax bacterium) in a city in Russia resulted in over 1,000 deaths in 1979. It is thought that this outbreak may have resulted from an accident at a biological warfare facility.

Biological warfare is among the least commonly used military strategies. Most military leaders have been reluctant to release microorganisms that might cause an uncontrolled outbreak of disease, affecting not only the enemy but friendly populations as well.

Microorganisms used as biological weapons

The microorganisms generally considered suitable for biological warfare include viruses, bacteria, protozoa, and fungi. Toxins (poisonous chemicals) produced by microorganisms also are considered biological weapons. These agents are capable of causing sickness or death in humans or animals, destroying crops, or contaminating water supplies.

Various bacteria have been used or experimented with as biological weapons. Anthrax is an infectious disease that can be passed from cattle and sheep to humans. Inhaling anthrax spores can result in a deadly form of pneumonia. During World War II (1939–45), Japan and Great Britain built and tested biological weapons carrying anthrax spores, and the inhalation of anthrax may still be a threat as a biological weapon today.

The toxin that causes botulism (pronounced BOTCH-uh-liz-um), a rare but deadly form of food poisoning, is regarded as one of the most powerful nerve poisons known to science. Ingestion of a very tiny amount can cause death. The toxin has been tested by the U.S. Army as a coating for bullets and as an ingredient in aerosols (for release into the air).

Brucellosis (pronounced broos-uh-LOHS-us) is a bacterial disease transmitted from animals to humans either by direct contact or by drinking the milk of infected goats and cows. It can be used as a biological weapon that does not kill people but makes them so ill that they are unable to resist an attack.

Words to Know

Microorganism: An organism so small that it can be seen only with the aid of a microscope.

Plague: A contagious disease that spreads rapidly through a population and results in a high rate of death.

Toxin: A poisonous substance produced by an organism.

Saxitoxin is a powerful poison produced by one-celled organisms called dinoflagellates (pronounced dye-no-FLAJ-uh-lets) that live in coastal waters. When present in large numbers, the organisms turn the water a reddish color (called red tides). Shellfish contaminated with saxitoxin can cause partial paralysis or even death in humans who eat them and have been considered for use as biological weapons by American military scientists.

Staphylococcus (pronounced staff-luh-KOCK-us) is any of several strains of bacteria that can cause mild to severe infection in humans. The more dangerous strains are the ones most often tested as possible biological weapons. Staphylococcus toxin can be dried and stored for up to a year without losing its effectiveness.

Tularemia (pronounced two-luh-REE-mee-uh) is a plaguelike bacterial disease often transmitted through insect bites. In humans, tularemia can cause fever, chills, headache, chest pain, and difficulty breathing. At one time, the U.S. Army considered tularemia as of the most promising of all biological weapons.

Genetically engineered weapons

The development of genetic engineering in the second half of the twentieth century has presented the possibility of creating even more dangerous forms of existing microorganisms—forms that could be used as biological weapons. Genetic engineering is the process of altering the genetic material of living cells in order to make them capable of (1) manufacturing new substances, (2) performing new functions, (3) being more easily produced, or (4) holding up well under storage.

The use and control of biological weapons

In 1925, the Geneva Protocol, a treaty banning the first use of biological and chemical weapons in war, was signed and ratified or officially approved by many nations, but not Japan or the United States (the U.S. government did not ratify the treaty until April 1975, some 50 years later). The treaty did not, however, prohibit the use of these weapons in response to an initial biological or chemical attack from an opponent.

Following the signing of the treaty, some nations, including Japan and the United States, conducted their own research on biological weapons, explaining that such studies were necessary in order to develop defensive measures against the use of such weapons by others.

The most serious violator of the Geneva Protocol was Japan, The Japanese military used biological warfare during the 1930s and 1940s in its conquest of China. In addition, captured American soldiers were used by Japan during World War II as test subjects in biological weapons experiments.

In the decades following World War II, the United States maintained a large and aggressive program of biological weapons research. Experiments and tests of biological agents were conducted at dozens of American army bases. In 1969, President Richard Nixon announced that the United States was discontinuing further research on biological and chemical weapons.

In 1972, eighty-seven nations (including the United States) signed the Biological Weapons Convention Treaty, which banned the development, testing, and storage of such weapons. The treaty was entered into force three years later. By 2000, the twenty-fifth anniversary of the treaty being entered into force, over 160 nations had signed the treaty; more than 140 of those had also ratified it. However, in 1982, President Ronald Reagan had declared that the world situation justified research on biological and chemical weapons and that the United States would return to a more ambitious program in this area.

As of the end of the twentieth century, over 450 repositories that sold and shipped plague, anthrax, typhoid fever, and other toxic organisms were located throughout the world. The shipment of pathogenic (disease-causing) organisms is not governed by international laws or treaties. Harmful bacteria can be grown in a garage or a backyard, and guidelines on growing bacteria are instantly available on the Internet. In a typical year, the Federal Bureau of Investigation (FBI) investigates about four times as many biological attack threats in the United States as either chemical or nuclear threats. Clearly, law enforcement by local, state, and federal authorities must be strengthened against the possibility of biological disaster.

[See also Bacteria; Chemical warfare; Poisons and toxins; Virus ]

Biological Warfare

BIOLOGICAL WARFARE. The history of warfare provides many examples of commanders who deliberately attempted to spread infectious disease in the camps of their enemies. The sophistication and effectiveness of the biological component of warfare has ranged from the relatively simple act of polluting water sources with the carcasses of dead animals and humans to the malicious distribution of smallpox-laden clothing into a susceptible population. Because it can be spread only through human-to-human contact and produces a horrifying set of symptoms with a high mortality rate, smallpox has the potential to be both manipulated by humans and highly destructive when introduced. Long before modern science was able to explain why smallpox spread so quickly and proved so deadly, humans knew enough about the disease to be able both to protect themselves and to facilitate its spread. Early in the eighteenth century, colonial Americans became aware of the practice of inoculation, a procedure whereby a small amount of infectious agent was deliberately introduced under the skin, producing a case of the disease that, for reasons that still cannot be fully explained, was significantly less deadly than if the individual had been infected via person-to-person contact. While it cannot be conclusively proven that outbreaks of smallpox during wartime in eighteenth-century North America were caused by human agency—the infection could have traveled via trade routes and contacts that were a regular and normal part of the environment—it is possible to demonstrate that humans did intentionally want to spread smallpox among their enemies during this time.

THE CASE OF AMHERST

The best documented case of intent occurred during Pontiac's War, when Major General Sir Jeffery Amherst, the British commander in chief in North America, wrote to Colonel Henry Bouquet on 7 July 1763 to ask: "Could it not be contrived to Send the Small Pox among those Disaffected Tribes of Indians [then laying siege to Fort Pitt]? We must, on this occasion, Use Every Stratagem in our power to Reduce them." Bouquet agreed with Amherst's suggestion in his reply of 13 July: "I will try to inocculate [sic] the Indians by means of [smallpox-infected] Blankets that may fall in their hands, taking care however not to get the disease myself." Neither senior officer knew that Captain Simon Ecuyer, the commander of Fort Pitt, and William Trent, a trader and land speculator then resident at the fort, had already put in motion the very plan that Amherst proposed. Elizabeth A. Fenn has written, "The eruption of epidemic smallpox in the Ohio country coincided closely with the distribution of infected articles by individuals at Fort Pitt. While blame for this outbreak cannot be placed squarely in the British camp, the circumstantial evidence is nevertheless suggestive" (Biological Warfare, p. 6).

WASHINGTON AND INOCULATION

Whether or not the British were guilty of spreading smallpox in 1763, senior American commanders were alive to the reality that American-born soldiers, living their lives in a disease environment where encounters with smallpox were episodic and deadly, were at significantly greater risk of falling prey to the disease than were their European-born opponents, who—besides having more exposure to the disease—were also regularly inoculated when recruited into military service. George Washington, who had survived his own encounter with smallpox on a voyage to Barbados in 1751, wrestled with the problem from the moment he arrived at Cambridge, Massachusetts, on 2 July 1775 to take command of the New England army besieging Boston. Rumors were rampant that Major General Thomas Gage, the British commander in chief in Boston, was trying to promote outbreaks of the disease in the American camps. Washington instituted measures to try to quarantine the disease but worried that, given the state of indiscipline in the army, his orders might not be followed. He considered inoculating the troops, but shrank from it because the army's medical facilities were still too primitive to manage the procedure effectively and because it would put too many men out of combat for too long in the face of an active and opportunistic enemy. He made sure that the first American troops entering Boston on 17 March 1776, after the British evacuation, were survivors of smallpox and thus had immunity against the disease.

The impact smallpox could have on an army was demonstrated vividly by the way it destroyed the American invasion of Canada in 1775–1776. American forces arrived outside the walls of Quebec in November 1775 and managed loosely to besiege the city over the ensuing winter and even to mount an unsuccessful assault on New Year's Eve, despite being at the end of a tenuous supply line that stretched all the way back to Albany, New York. But when smallpox broke out among the troops in the spring—deliberately introduced, it was rumored, by Major General Sir Guy Carleton, the British commander in Canada—American morale crumbled. Abandoning dead and dying comrades along the roadside, the survivors fled up the St. Lawrence and then south toward Lake Champlain. Major General John Thomas, himself a medical doctor, eventually authorized inoculation, but it was too late; Thomas himself succumbed to smallpox at Fort Chambly on 2 June 1776.

Washington still vacillated about inoculating the army. In a letter to Horatio Gates of 5 February 1777 he admitted, "I am much at a loss what Step to take to prevent the spreading of the smallpox; should We Innoculate generally, the Enemy, knowing it, will certainly take advantage of our situation." Literally overnight, he came to a decision. In the postscript he added the next morning, he told Gates: "Since writing the above, I have come to the Resoluto. of Innoculatg the Troops, and have given Orders to that purpose as well at Philada [Philadelphia] as here [Morristown, New Jersey]. This is the only effectual Method of putting a Period to the Disorder." Inoculation became standard practice in the army for the remainder of the war. It was one of Washington's most important decisions.

THE BRITISH AND SMALLPOX

Smallpox was epidemic across the North American continent from 1775 through 1782, so it is impossible to prove that the British deliberately used smallpox as a weapon. That some British senior officers saw smallpox as an added way to injure the rebels is beyond dispute, however. During the campaign in Virginia in 1781, thousands of African American slaves liberated themselves by joining the tail of the various British expeditions that crisscrossed the state that summer. African Americans were as likely to contract smallpox as any Americans, and soon the freedmen and freedwomen were being ravaged by disease. The British in truth did not have the resources to help them, but instead of trying, senior commanders turned them out, knowing full well that they might carry smallpox back to the rebels. From Portsmouth on 13 July, Major General Alexander Leslie told Charles Earl Cornwallis that "Above 700 Negroes are come down the River in the Small Pox; I shall distribute them about the Rebell Plantations." Cornwallis himself, as he sat his army down at Yorktown to await the relief that never came, expelled perhaps several thousand former slaves. American soldiers, at least, thought he did so to spread smallpox in the besieging army. According to the memoirs of Joseph Plumb Martin, "During the siege, we saw in the woods herds of Negroes which Lord Cornwallis (after he had inveigled them from their proprietors), in love and pity to them, had turned adrift, with no other recompense for their confidence in his humanity than the smallpox for their bounty and starvation and death for their wages."

SMALLPOX'S IMPACT

While smallpox did influence the outcome of some campaigns, most notably the invasion of Canada in 1775–1776, it did not determine the outcome of the war. What it did do was increase human suffering, not just among the soldiers and camp followers, but in the communities to which the passage of armies and the return of veterans communicated the disease. Specific evidence is lacking, but it all probability smallpox killed more people during the war than died as a result of direct military action.

BIBLIOGRAPHY

Cash, Philip. Medical Men at the Siege of Boston. Philadelphia: American Philosophical Society, 1973.

Fenn, Elizabeth A. "Biological Warfare in Eighteenth-Century North America: Beyond Jeffery Amherst." Journal of American History 86 (2000): 1-55.

―――――――. Pox Americana: The Great Smallpox Epidemic of 1775–82. New York: Hill and Wang, 2001.

Scheer, George F., ed. Private Yankee Doodle: Being a Narrative of Some of the Adventures, Dangers, and Sufferings of a Revolutionary Soldier, Joseph Plumb Martin. Boston, Mass.: Little, Brown, 1962.

Twohig, Dorothy, et al., eds. The Papers of George Washington, Revolutionary Series. Vol. 8, January-March 1777. Charlottesville: University Press of Virginia, 1998.

                              revised by Harold E. Selesky