Bubonic plague as a biological weapon
Bubonic plague is a highly contagious bacterial disease caused by the bacterium Yersinia pestis, known for its severe impact on human health and high mortality rates. Historically referred to as the Black Death, it is transmitted primarily by fleas associated with infected rodents and can also spread through contact with bodily fluids or aerosols from infected individuals. The disease manifests in three forms: bubonic, pneumonic, and septicemic, with untreated cases showing mortality rates ranging from 50-100%. Current treatment typically involves antibiotics, although a vaccine exists, it is not widely available in the United States.
Given its dangerous characteristics, bubonic plague has raised concerns regarding its potential use as a biological weapon. The possibility of weaponized Yersinia pestis strains, including those resistant to antibiotics, has been explored in various biological weapons programs. As natural outbreaks still occur globally, with around 1,666 cases reported annually, effective rapid identification and isolation of cases are critical in managing any potential bioterrorism threats. Understanding the implications of bubonic plague as a biological weapon is vital for public health preparedness and response strategies.
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Bubonic plague as a biological weapon
Definition: Highly contagious human bacterial disease with a very high rate of mortality.
Significance: Natural outbreaks of bubonic plague still occur periodically, with an average of 18 cases in the United States and 1,666 cases worldwide per year. A larger cause for concern, however, is the possibility that weaponized plague bacteria could be used in biological terrorism.
Bubonic plague is caused by a gram-negative, facultative anaerobe bacterial species, Yersinia pestis, acting as an intracellular parasite. The disease is transmitted primarily by fleas from infected hosts, including more than two hundred species of rodents as well as domestic cats, dogs, rabbits, and even sheep or camels. Transmission may also occur through contact with infected bodily fluids or tissues as well as through aerosol exposure from a coughing patient. The bubonic plague is also known as the Black Death because it results in buboes, infected and inflamed lymph nodes that turn black as they become necrotic and hemorrhagic.
Three forms of plague are known. The skin form of the disease, bubonic plague, has a mortality rate of 50-90 percent if untreated and up to 15 percent if treated. A second form, pneumonic plague, results when the bacteria invade the lungs. Pneumonic plague is especially virulent, with mortality of 100 percent if not treated within twenty-four hours. Moreover, it causes bronchial pneumonia, which leads to coughing of highly infective aerosols of bacteria. The third form of plague is septicemic plague, in which blood-borne bacteria are widespread throughout the body, invading almost all organs. Septicemic plague is 100 percent fatal if untreated, and some 40 percent of those who contract it die even with treatment. Incubation time for plague before symptoms appear is one to six days.
Symptoms of bubonic plague include fever (as high at 105 degrees Fahrenheit), chills, muscular pain, sore throat, headache, severe weakness, extreme malaise, and enlarged, painful lymph nodes especially in the groin, armpits, and neck. In later stages, accelerated heart rate, accelerated breathing, and low blood pressure ensue. The normal course of treatment is antibiotics of the tetracycline or sulfonamide families. A vaccine does exist, but it is no longer available in the United States; it is used to contain local outbreaks in other parts of the world.
Because of the highly contagious nature of Y. pestis, this organism poses a grave danger as an agent in a biological terrorism attack. Aerosolized plague organisms as well as antibiotic-resistant strains of plague have been developed in former biological weapons facilities in Russia and the United States. Rapid identification of the agent is essential in any bioterrorism event.
Bibliography
Brubaker, Bob. “Yersinia pestis and the Bubonic Plague.” In The Prokaryotes, edited by Martin Dworkin et al. 3d ed. Vol. 6. New York: Springer, 2006.
Orent, Wendy. Plague: The Mysterious Past and Terrifying Future of the World’s Most Dangerous Disease. New York: Free Press, 2004.
Parker, Philip M., and James N. Parker. Bubonic Plague: A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References. San Diego, Calif.: ICON Health Publications, 2003.