Expertise in dealing with biological weapons (BWs) requires specific knowledge from the fields of infectious disease, epidemiology, toxicology, and public health. Biological and chemical weapons share many characteristics in common, including intent of use, some dispersion methods, and initial defense based on adequate personal protective equipment and decontamination (Tables 126–2 and 126–3). However, key differences between biological and chemical weapons involve a greater delay in onset of clinical symptoms after exposure to BWs; that is, the incubation period for most BWs is greater than the latent period for most chemical weapons. Decontamination is less crucial for victims exposed to BWs. Additionally, a few BWs can reproduce in the human host and cause secondary casualties, and disease after exposure to certain BWs can be prevented by the timely administration of prophylactic medications.
Biological weapons may be bacteria, fungi, viruses, or toxins derived from microorganisms. Some fungi are listed as potential BWs; however, none are known to have been developed into weapons to date.72 Because toxin weapons are not living organisms, some authorities classify them as chemical rather than BWs. For the purpose of discussion in this chapter, toxin weapons derived from microorganisms will be considered BWs. Most of these bacterial BWs exert their effects by elaborating protein toxins.
Many diseases caused by BWs are either infrequently encountered in modern clinical medicine, such as anthrax and plague, or no longer occur naturally, such as smallpox. Therefore, health care personnel require specific training in recognizing and managing biological warfare victims. Potential BWs are categorized by their risk of causing mass casualty outbreaks.14 The high-risk BWs are more easily disseminated or transmitted and may cause high mortality and potential public health disasters; these BWs include smallpox, anthrax, plague, botulism, tularemia, and several hemorrhagic fever viruses. The moderate-risk BWs include Q fever, brucellosis, the equine encephalitis viruses, ricin, and staphylococcal enterotoxin B, all of which are briefly discussed in this chapter.
Biological warfare has ancient roots. Missile weapons poisoned with natural toxins were used as early as 18,000 years ago (Chap. 1). Other uses of biological warfare before the modern era relied mainly on poisoning water supplies with natural toxins or spreading naturally occurring epidemic infections to the enemy by hurling infected corpses over battlements or through the intentional transfer of disease-contaminated goods (eg, smallpox blankets).
During World War I, Germany was the only combatant nation with an active BW program; however, by World War II, many nations had BW research programs, including Japan, the Soviet Union, Germany, France, Britain, Canada, and the United States. The Japanese program included field trials with bubonic plague and conducted BW experiments on prisoners of war and civilians.35 The American program was founded at Camp Detrick, Maryland, in 1942. Fort Detrick, as it is now known, remains the home of the United States Army Medical ...