Biological warfare (BW)—also known as germ warfare—is the use of biological toxins or infectious agents such as bacteria, viruses, and fungi with the intent to kill or incapacitate humans, animals or plants as an act of war. Biological weapons (often termed "bio-weapons", "biological threat agents", or "bio-agents") are living organisms or replicating entities (viruses, which are not universally considered "alive") that reproduce or replicate within their host victims. Entomological (insect) warfare is also considered a type of biological weapon. This type of warfare is distinct from nuclear warfare and chemical warfare, which together with biological warfare make up NBC, the military initialism for nuclear, biological, and chemical warfare using weapons of mass destruction (WMDs). None of these is a conventional weapon, which are deployed primarily for their explosive, kinetic, or incendiary potential.

Biological weapons may be employed in various ways to gain a strategic or tactical advantage over the enemy, either by threats or by actual deployments. Like some of the chemical weapons, biological weapons may also be useful as area denial weapons. These agents may be lethal or non-lethal, and may be targeted against a single individual, a group of people, or even an entire population. They may be developed, acquired, stockpiled or deployed by nation states or by non-national groups. In the latter case, or if a nation-state uses it clandestinely, it may also be considered bioterrorism.

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M125 bomblet
The M125 bomblet was a U.S. chemical sub-munition designed to deliver the nerve agent sarin. It was brought into service in 1954 with the M34 cluster bomb as part of the first U.S. air-delivered nerve agent weapon. The M125 bomblet was a sub-munition of the M34 cluster bomb, which was first brought into regular service by the United States Army in 1954. In development the M125 was known as the E54R6 bomblet (shortened to E54). The M34 and its payload of M125s was the first air-delivered nerve agent weapon in the U.S. chemical arsenal. Later, the Chemical Corps developed chemical-biological warheads for multiple missile systems including, Matador, Rascal, Snark, and Navaho missiles. These warheads incorporated the M125 bomblet and the M114 bomblet. Over 21,000 of the M125 containing M34 bombs were destroyed at Rocky Mountain Arsenal in 1976.

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Soldiers wearing gas masks
Credit: U.S. Navy photo by Photographer's Mate 1st Class Timm Duckworth

A gas mask is a mask worn over the face to protect the wearer from inhaling "airborne pollutants" and toxic gases. The mask forms a sealed cover over the nose and mouth, but may also cover the eyes and other vulnerable soft tissues of the face. Some gas masks are also respirators, though the word gas mask is often used to refer to military equipment (e.g. Field Protective Mask, etc.) (The user of the gas mask is not protected from gas that the skin can absorb.)

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Cholera rehydration
Cholera, sometimes known as Asiatic or epidemic cholera, is an infectious gastroenteritis caused by enterotoxin-producing strains of the bacterium Vibrio cholerae. Transmission to humans occurs through eating food or drinking water contaminated with Vibrio cholerae from other cholera patients. The major reservoir for cholera was long assumed to be humans themselves, but considerable evidence exists that aquatic environments can serve as reservoirs of the bacteria. Vibrio cholerae is a Gram-negative bacterium that produces cholera toxin, an enterotoxin, whose action on the mucosal epithelium lining of the small intestine is responsible for the disease's most salient characteristic, exhaustive diarrhea. In its most severe forms, cholera is one of the most rapidly fatal illnesses known, and a healthy person's blood pressure may drop to hypotensive levels within an hour of the onset of symptoms; infected patients may die within three hours if medical treatment is not provided. In a common scenario, the disease progresses from the first liquid stool to shock in 4 to 12 hours, with death following in 18 hours to several days, unless oral (or, in more serious cases, intravenous) rehydration therapy is provided. It is estimated that most cases of cholera are unreported due to poor surveillance systems, particularly in Africa. Fatality rates are 5% of total cases in Africa, and less than 1% elsewhere.

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Cholera bacteria SEM



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Christian B. Anfinsen
We could develop warheads to spread anthrax (disease) within six months and so could the Soviets. ... Since you can make any number of variables, the defense against them is impossible. The inability to defend against such an attack is universal.


Biological agents
Biological warfare topics
Modern bioterrorist incidents
Prevention and response

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