Encyclopedia
Bubonic plague is the best-known variant of the deadly infectious disease
plague, which is caused by the enterobacteria
Yersinia pestis.Overview
Plague has affected human society for millennia. Numerous scientists believe that it was responsible for the
Black Death, which killed perhaps a third of Europe's population during the Middle Ages, with additional large numbers of casualties in Asia and the Middle East.
Plague is endemic in many countries in Africa, in the former Soviet Union, the Americas and Asia. In 2003, nine countries reported 2,118 cases to the WHO , of which 182 ended in death. All were isolated cases, except for an outbreak in a village in Algeria , which caused eleven infections and one death. Plague is most common in
Madagascar and the
Democratic Republic of the Congo. These two countries have on average 600 to 800 cases each year. They accounted for 2,025 of the 2,118 cases and 177 of the 182 deaths in 2003. Other countries with annual but many fewer cases are
Tanzania,
Peru,
United States,
China,
Mongolia and
Vietnam. According to the WHO, the actual number of cases in the world is probably much higher than reported, due to the reluctance of certain countries to declare cases, the lack of diagnosis because the clinical picture of cases is not very specific, and the absence of laboratory confirmation
The most recent outbreak of plague happened in Zobia, in the northern part of the
Democratic Republic of the Congo in December 2004. The outbreak, which only appeared as the variant pneumonic plague, began among workers in a diamond mine. By mid-March 2005, when the WHO regarded the outbreak as over, 130 people had been infected, of whom 97 died.
There has not been a plague epidemic for many years.
Infection/transportation
Plague is primarily a disease of rodents, particularly
marmots , but also
black rats,
prairie dogs,
chipmunks,
squirrels and other similar large rodents.
Human infection most often occurs when a person is bitten by a
rat flea that has fed on an infected rodent. The bacteria multiply inside the flea, sticking together to form a plug that blocks its stomach and causes it to become very hungry. The flea then voraciously bites a host and continues to feed, even though it is unable to satisfy its hunger. During the feeding process, blood cannot flow into the blocked stomach, and consequently the flea vomits blood tainted with the bacteria back into the bite wound. The Bubonic plague bacteria then infects a new host, and the flea eventually dies from starvation. Any serious outbreak of plague is usually started by other disease outbreaks in rodents, or some other crash in the rodent population. During these outbreaks, infected fleas that have lost their normal hosts seek other sources of blood.
In 1894, two bacteriologists, the French
Alexandre Yersin and the Japanese Shibasaburo Kitasato, independently isolated the responsible bacterium in
Hong Kong during the
Third Pandemic. Though both investigators reported their findings, a series of confusing and contradictory statements by Kitasato eventually led to the acceptance of Yersin as the primary discoverer of the organism. Yersin named it
Pasteurella pestis in honour of the Pasteur Institute, where he worked, but in 1967 it was moved to a new genus, renamed
Yersinia pestis in honour of Yersin. Yersin also noted that rats were affected by plague not only during plague epidemics but also often preceding such epidemics in humans, and that plague was regarded by many locals as a disease of the rats: villagers in China and India asserted that, when large numbers of rats were found dead, plague outbreaks in people soon followed.
In 1898, the French scientist Paul-Louis Simond established the rat-flea vector that drives the disease. He had noted that persons who became ill did not have to be in close contact with each other to acquire the disease. In Yunnan, China, inhabitants would flee from their homes as soon as they saw dead rats, and on the island of Formosa , residents considered handling dead rats a risk for developing plague. These observations led him to suspect that the flea might be an intermediary factor in the transmission of plague, since people acquired plague only if they were in contact with recently dead rats, but not affected if they touched rats that had been dead for more than 24 hours. In a now classic experiment, Simond demonstrated how a healthy rat died of plague after infected fleas had jumped to it from a plague-dead rat.
Types
Depending on the symptoms and the route of infection, plague appears in several forms, classified by the WHO with different ICD-10 codes:
- Main disease:
- Plague . Infections caused by Yersinia pestis.
- Forms:
- Bubonic plague occurs when Yersinia pestis causes an inflammation of the lymph nodes, making them tender and swollen . This is the most common form of plague.
- Cellulocutaneous plague is a very unusual form, with Yersinia pestis causing a skin infection.
- Pneumonic plague or pulmonic plague occurs when the lungs are infected by Yersinia pestis. The second most common form of plague. It may be a secondary infection, caused by bacteria spreading from the lymph nodes and reaching the lungs, but can also exist on its own, caused by inhalation of airborne bacteria.
- Meningeal plague or plague meningitis looks like meningitis at the outset. It is most common in children and is usually the end result of ineffective treatment for other forms of plague. Unusual.
- Pharyngeal plague occurs when Yersinia pestis is consumed, often through food. It can resemble tonsillitis. Very rare form.
- Septicemic plague occurs when Yersinia pestis multiply in the blood. The third most common form. It is usually associated with hunting and skinning of animals, but can also occur secondary to bubonic and pneumonic plague.
- Other forms of plague include the milder forms abortive plague, asymptomatic plague and pestis minor, all three often resulting only in a mild fever and light swelling of the lymph glands, usually resolved in approximately a week if appropriate treatment is given.
Clinical features
Bubonic plague becomes evident three to seven days after the infection. Initial symptoms are chills, fever, diarrhea, headaches, and the swelling of the infected lymph nodes, as the bacteria replicate there. If untreated, the rate of mortality for bubonic plague is 30–75%.
In septicemic plague there is bleeding into the skin and other organs, which creates black patches on the skin. There are bite-like bumps on the skin, commonly red and sometimes white in the center. Untreated septicemic plague is universally fatal, but early treatment with antibiotics reduces the mortality rate to 4 to 15%. People who die from this form of plague often die on the same day symptoms first appear.
With
pneumonic plague infecting
lungs comes 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
hemoptysis, are 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%.
Treatment
An Indian doctor of Russian-Jewish origin
Vladimir Havkin was the first to invent and test a plague vaccine.
The traditional treatments are:
- Streptomycin 30 mg/kg IM twice daily for 7 days
- Chloramphenicol 25–30 mg/kg single dose, followed by 12.5–15 mg/kg four times daily
- Tetracycline 2 g single dose, followed by 500 mg four times daily for 7–10 days
More recently,
have also been shown to be effective.
History
Historical plague epidemics
The earliest account, familiar to the West, describing a possible plague epidemic is found in I Samuel 5:6 of the
Hebrew Bible. In this account, the
Philistines of
Ashdod were struck with a plague for the crime of stealing the
Ark of the Covenant from the Children of Israel. These events have been dated to approximately the second half of the eleventh century B.C. The word "tumors" is used in most English translations to 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 ,
Thucydides described the coming of an epidemic disease which was reputed to have begun in
Ethiopia, passed through
Egypt and
Libya, and then came to the Greek world. In this Plague of Athens the city lost possibly one third of its population, including
Pericles . Modern historians disagree on whether the plague was a critical factor in the loss of the war. This epidemic has long been considered an outbreak of plague. However, from Thucydides' description, more modern scholars dispute this, feeling that
typhus,
smallpox or
measles may be better candidates. A recent study of the DNA found in the dental pulp of plague victims suggests that typhoid was actually responsible. Other scientists dispute these findings, citing serious methodologic flaws in the DNA study.
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
Alexandria in the third century B.C. If this is correct, the eastern
Mediterranean world may have been familiar with bubonic plague at that early date.
The last significant European outbreak of plague occurred in
Russia in A.D. 1877–1889 in rural areas near the
Ural Mountains and the
Caspian Sea. This outbreak is sometimes seen as an extension of the
Third Pandemic . Efforts in hygiene and patient isolation reduced the spread of the disease, with approximately 420 deaths in the region. Significantly, the region of Vetlianka in this area is near a population of the
bobak marmot, a small rodent considered a very dangerous plague reservoir.
Historical Pandemics
Plague of Justinian
- For more complete information, see Plague of Justinian.
The
Plague of Justinian in A.D. 541–542 is the first known pandemic on record, and marks the first firmly recorded pattern of bubonic plague. This outbreak is thought to have originated in Ethiopia or Egypt. The huge city of
Constantinople imported 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 Constantinople every 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 wave of plague spread through the Mediterranean into what is now France. A maximum of 25 million dead is considered a reasonable estimate.
Black Death
- For more complete information, see Black Death.
During the mid-
14th century, the
Black Death, a massive and deadly pandemic, swept through
Eurasia, killing approximately one third of the population and changing the course of Asian and European history. The estimated 237 million victims throughout the many years of infection, constituted the largest death toll from any known non-viral epidemic. Many scientists and historians believe the Black Death was an incidence of plague, with a strong presence of the more contagious pneumonic and septicemic varieties increasing the pace of infection, spreading the disease deep into inland areas of the continents.
Plague continued to strike parts of
Europe throughout the
14th century, the
15th century and the
16th century with 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.
Third Pandemic
- For more complete information see Third Pandemic.
The
Third Pandemic began in
China in 1855, spreading plague to all inhabited continents and ultimately killing more than 12 million people in
India and China alone. Casualty patterns indicate that waves of this pandemic may have come 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
Manchuria and
Mongolia. Researchers during the "Third Pandemic" identified plague vectors and the plague bacterium , leading in time to modern treatment methods.
Plague as a biological weapon
Plague has a long history as a
biological weapon. Historical accounts from
medieval Europe detail the use of infected animal carcasses, such as cows or horses, and human carcasses, by
Mongols,
Turks and other groups, to contaminate enemy water supplies. Plague victims were also reported to have been tossed by
catapult into cities under siege.
During
World War II, the Japanese Army developed weaponised plague, based on the breeding and release of large numbers of fleas. During the Japanese occupation of
Manchuria,
Unit 731 deliberately infected civilians and
prisoners of war with the plague bacterium. These subjects, called "logs", were then studied by
dissection, some while still living and conscious. After World War II, both the
United States and the
Soviet Union developed means of weaponising pneumonic plague. Experiments included various delivery methods, vacuum drying, sizing the bacterium, developing strains resistant to antibiotics, combining the bacterium with other diseases, such as
diphtheria, and genetic engineering. Scientists who worked in
USSR bio-weapons programs have stated that the Soviet effort was formidable and that large stocks of weaponised plague bacteria were produced. Information on many of the Soviet projects is largely unavailable. Aerosolized pneumonic plague remains the most significant threat.
Contemporary cases
The disease still exists in wild animal populations from the
Caucasus Mountains east across southern and central
Russia, to
Kazakhstan,
Mongolia, and parts of
China; in
Southwest and
Southeast Asia,
Southern and
East Africa ; in
North America, from the
Pacific Coast eastward to the western
Great Plains, and from
British Columbia south to
Mexico; and in
South America in two areas: the
Andes mountains and
Brazil. There is no plague-infected animal population in
Europe or
Australia.
- In modern London, the rat is a growing problem, and not just growing in numbers. They are also much bigger -- the average brown rat, Rattus norvegicus, is normally under a foot long and is a scrawny scavenger weighing in at less than a pound. However, London rat-catcher
...
s now report finding them twice that size.
- On 15 September, 2005, ABC News reported that three mice infected with Yersinia pestis apparently disappeared from a laboratory belonging to the Public Health Research Institute, located on the campus of the University of Medicine and Dentistry of New Jersey, which conducts anti-bioterrorism research for the United States government.
- On 19 April, 2006, CNN News and others reported a case of plague in Los Angeles, California, the first reported case in that city since 1984.
- On 16 May, 2006, KSL reported a case of plague found in small vermin at Natural Bridges about 40 miles west of Blanding in San Juan County, Utah
- On 28 June, 2006, AZ Central reported a case of plague found in a cat.
- In the U.S., about half of all human cases of plague since 1970 have occurred in New Mexico. There were 2 plague deaths in the state in 2006, the first fatalities in 12 years.
- One hundred deaths resulting from pneumonic plague were reported in Ituri district of the eastern Democratic Republic of the Congo in June 2006. Control of the plague was proving difficult due to the ongoing conflict.
Uses in literature
...
set in early 17th century in Northern Italy, is one of the most read and better known classical novels in Italian literature. Contains a detailed and vivid account of society during the plague outbreak in its time.
- Narcissus and Goldmund by Hermann Hesse . A fictional account in which the main character ends up witnessing the effects of the plague first-hand.
- The Plague by Albert Camus depicts an outbreak of plague at the Algerian city of Oran. The disease, often interpreted as a metaphor for the German occupation of France in World War II, serves as a means for the author to examine his characters' responses to hardship, suffering and death.
- The Black Death by Gwyneth Cravens and John S Marr is a disaster novel depicting an outbreak of plague in present-day New York City through the eyes of health workers and government officials.
- Doomsday Book by Connie Willis . A Hugo award and Nebula award-winning historical science fiction novel, in which a time-traveler inadvertently ends up in the plague-ridden England of 1348.
- The Years of Rice and Salt is an alternate history [i] novel [i] written by science fiction [i] ...
by Kim Stanley Robinson . Presents an alternate history of the world where the population of Europe is obliterated by the Black Death setting the stage for a world without Europeans and Christianity. - by Geraldine Brooks . Based on a historical village whose denizens quarantined themselves to avoid further spread of the disease.
References
- Biraben, Jean-Noel. Les Hommes et la Peste The Hague 1975.
- Cantor, Norman F., In the Wake of the Plague: the Black death and the World It Made New York: Harper 2001.
- de Carvalho, Raimundo Wilson; Serra-Freire, Nicolau Maués; Linardi, Pedro Marcos; de Almeida, Adilson Benedito; and da Costa, Jeronimo Nunes . . Memórias do Instituto Oswaldo Cruz 96, 603–609. PMID 11500756. this manuscript reports a census of potential plague vectors in a Brazilian focus region ; free PDF download Retrieved 2005-03-02
- Gregg, Charles T. Plague!: The shocking story of a dread disease in America today. New York, NY: Scribner, 1978, ISBN 0-684-15372-6.
- Kelly, John. The Great Mortality: An Intimate History of the Black Death, the Most Devastating Plague of All Time. New York: HarperCollins Publishers Inc., 2005. ISBN 0-06-000692-7.
- McNeill, William H. Plagues and People. New York: Anchor Books, 1976. ISBN 0-385-12122-9. Reprinted with new preface 1998.
- Orent, Wendy. Plague: The Mysterious Past and Terrifying Future of the World's Most Dangerous Disease. New York: Free Press, 2004. ISBN 0-7432-3685-8.
- Patrick, Adam. "Disease in Antiquity: Ancient Greece and Rome," in Diseases in Antiquity, editors: Don Brothwell and A. T. Sandison. Springfield, Illinois; Charles C. Thomas, 1967.
- Platt, Colin. King Death: The Black Death and its Aftermath in Late-Medieval England Toronto University Press, 1997.
- Simpson, W. J. A Treatise on Plague. Cambridge, England: Cambridge University Press, 1905.
- Spielvogel, Jackson J. Western Civilization: A Brief History Vol. 1: to 1715. Belmont, Calif.: West/Wadsworth, 1999, Ch. 3, p. 56, paragraph 2. ISBN 0-534-56062-8.
- ABC News, , 2005-09-15
Numbered references
See also
External links
