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Bubonic plague
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TypesICD-10codes are provided below.
Infection/transportationBubonic plague is primarily a disease of rodents, particularly marmots(in which the most virulent strains of plague are primarily found), but also black rats, prairie dogs, chipmunks, squirrelsand other similar large rodents. Humaninfection most often occurs when a person is bittenby a rat flea(Xenopsylla cheopsis) that has fed on an infected rodent. The bacillus multiplies in the stomach of the flea, blocking it. When the flea next bites a mammal, blood consumed by the flea is regurgitated along with the bacillus into the bloodstream of the bitten animal. Any serious outbreak of plague is started by other disease outbreaks in the rodent population. During these outbreaks, infected fleas that have lost their normal hosts seek other sources of blood. In 1894, bacteriologists Alexandre Yersinand Shibasaburo Kitasatoindependently isolated the responsible bacterium and Yersin further determined that rodents were the likely common mode of transmission. The disease is caused by the bacteriumYersinia pestis. Symptoms and treatmentThe disease becomes evident 2–7 days after infection. Initial symptoms are chills, fever, headaches, and the formation of buboes. The buboes are formed by the infection of the lymph nodes, which swell and become prominent. If unchecked, the bacteria infects the bloodstream (septicemic plague), and can progress to the lungs (pneumonic plague). If untreated, the rate of mortality for bubonic plague is 30-75%. In septicemicplague there is bleeding into the skin and other organs, which creates black patches on the skin. Untreated septicemic plague is universally fatal, but early treatment with antibiotics(usually streptomycinor gentamicin) is effective, reducing the mortality rate to around 15% (USA 1980s). People who die from this form of plague often die on the same day symptoms first appear. With pneumonicplague infecting lungscomes the possibility of person-to-person transmission through respiratory droplets. The incubation period for pneumonic plague is usually between two and four days, but can be as little as a few hours. The initial symptoms of headache, weakness, and coughing with hemoptysisare indistinguishable from other respiratory illnesses. Without diagnosis and treatment, the infection can be fatal in one to six days; mortality in untreated cases may be as high as 95%. The disease can be effectively treated with antibiotics. HistoryHistorical epidemicsThe first Western literary account of a possible outbreak of plague is found in the book of I Samuel 5:6 of the Hebrew Bible. In this account, the Philistinesof Ashdodwere struck with a plague for the crime of stealing the Ark of the Covenantfrom the Children of Israel. These events have been dated to approximately the second half of the eleventh century B.C. The word "hemorrhoids" is used in Englishtranslationsto describe the sores that came upon the Philistines. The Hebrew, however, can be interpreted as "swelling in the secret parts". The account indicates that the Philistine city and its political territory were struck with a "ravaging of mice" and a plague, bringing death to a large segment of the population. In the second year of the Peloponnesian War(430 B.C.), Thucydidesdescribed the coming of an epidemic disease which began in Ethiopia, passed through Egyptand Libya, and then came to the Greek world. Athenswas decimated by this plague, losing possibly one-third of its population, including Pericles(Speilvogal, J, 1999, pp. 56). The loss of population did not affect the progress and outcome of the war. This epidemic has long been considered an outbreak of bubonic plague. However, from Thucydides' description, some modern scholars dispute the assignment of plague, feeling that smallpoxor measlesmay be better candidates. In the first century AD, Rufus of Ephesus, a Greek anatomist, refers to an outbreak of plague in Libya, Egypt, and Syria. He records that Alexandrian doctors named Dioscorides and Posidonius described symptoms including acute fever, pain, agitation, and delirium. Buboes—large, hard, and non-suppurating—developed behind the knees, around the elbows, and "in the usual places." The death toll of those infected was very high. Rufus also wrote that similar buboes were reported by a Dionysius Curtus, who may have practiced medicine in Alexandriain the third century B.C. If this is correct, the eastern Mediterraneanworld may have been familiar with bubonic plague at that early date. (ref. Simpson, W.J., Patrick, A.) The last significant European outbreak of bubonic plague occurred in Russiain A.D. 1877–1889 in rural areas near the Ural Mountainsand the Caspian Sea. This outbreak is sometimes seen as an extension of the Third Pandemic(see below). Efforts in hygiene and patient isolation reduced the spread of the disease, with approximately 420 deaths in the region. Significantly, the region of Vetliankain this area is near a population of the "bobak", a type of small marmotconsidered a very dangerous plague reservoir. Historical pandemicsPlague of Justinian
The Plague of Justinian is the first known pandemicon record, and marks the first firmly recorded pattern of bubonic plague in A.D. 541–542. This outbreak is thought to have originated in Ethiopia or Egypt. The huge city of Constantinopleimported massive amounts of grain, mostly from Egypt, to feed its citizens. The grain ships may have been the source of contagion for the city, with massive public granaries nurturing the rat and flea population. At its peak the plague was killing 5,000 people in Constantinopleevery day and ultimately destroyed perhaps 40 percent of the city's inhabitants. It went on to destroy up to a quarter of the human population of the eastern Mediterranean. In A.D. 588 a second major plague wave spread through the Mediterranean into what is now France. A maximum of 25 million dead is considered a reasonable estimate. Black Death
During the mid-14th century, the Black Death, a massive and deadly epidemic, swept through Eurasia, killing one-third of the population (according to some estimates) and changing the course of Asian and European history. The 200 million victims, throughout the many years of infection, constituted the largest death toll from any known epidemic. Many scientists and historians believe the Black Death was an incidence of bubonic plague. A strong presence of the more contagious pneumonic and septicemic varieties increased the pace of infection, spreading the disease deep into inland areas of the continents. Plague continued to strike parts of Europethroughout the 15th century, the 16th centuryand the 17th centurywith varying degrees of intensity and fatality. Researchers still do not agree on why large outbreaks of the infection have not returned to Europe; however, changes in hygiene habits and strong efforts within public health and sanitation probably had a significant impact on the rate of infection from the infectuous disease. Third Pandemic
The Third Pandemicbegan in Chinain 1855, spreading the bubonic plague to all inhabited continents, and ultimately killing more than 12 million people in Indiaand China alone. Casualty patterns indicate that waves of this pandemic may have been from two different sources. The first was primarily bubonic and was carried around the world through ocean-going trade, transporting infected persons, rats, and cargos harboring fleas. The second, more virulent strain was primarily pneumonic in character, with a strong person-to-person contagion. This strain was largely confined to Manchuriaand Mongolia. Researchers during the "Third Pandemic" identified plague vectors and the plague bacillus, leading in time to modern treatment methods. Plague as a biological weaponPlague has a long history as a biological weapon. Historical accounts from medieval Europedetail the use of infected animal carcasses, such as cows or horses, by Mongols, Turksand other groups, to contaminate enemy water supplies. Plague victims were also reported to have been tossed by catapultinto cities under siege. During World War II, the Japanese Armydeveloped weaponized plague based on the breeding and release of large numbers of fleas. During the Japanese occupation of Manchuria, Unit 731deliberately infected civiliansand prisoners of warwith the plague bacillus. These subjects, called "logs", were then studied by dissection, some while still living and conscious. After World War II, both the United Statesand the Soviet Uniondeveloped means of weaponizing pneumonic plague. Experiments included various delivery methods, vacuum drying, sizing the bacillus, developing strains resistant to antibiotics, combining the bacillus with other diseases, such as diphtheria, and genetic engineering. Scientists who worked in USSRbio-weapons programs have stated that the Soviet effort was formidable and that large stocks of weaponized plague bacillus were produced. Information on many of the Soviet projects is largely unavailable. Aerosolized pneumonic plague remains the most significant threat. Image:World distribution of plague 1998.PNG Contemporary casesThe disease still exists in wild animal populations from the Caucasus Mountainseast across southern and central Russia, to Kazakhstan, Mongolia, and parts of China; in Southwestand Southeast Asia, Southernand East Africa(including the island of Madagascar); in North America, from the Pacific Coasteastward to the western Great Plains, and from British Columbiasouth to Mexico; and in South Americain two areas: the Andesmountains and Brazil. There is no plague-infected animal population in Europeor Australia. Globally, the World Health Organizationreports 1,000 to 3,000 human cases of plague every year. On 2005-09-15, ABC Newsreported[1]that three mice infected with the bacteria responsible for bubonic plague apparently disappeared from a laboratory. The mice were unaccounted-for at the Public Health Research Institute, which is on the campus of the University of Medicine and Dentistry of New Jerseyand conducts anti-bioterrorismresearch for the United Statesfederal government. Uses in literature
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Categories: Infectious diseases| Epidemics| Pandemics| Biological weapons| Zoonoses
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