Bubonic plague
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Yersinia pestis seen at 2000x magnification. This bacterium, carried and spread by fleas, is the cause of the various forms of the disease plague. |
Bubonic plague is the best-known variant of the deadly
infectious disease plague, which is caused by the
enterobacteria Yersinia pestis.Plague has affected human society for millennia. Most 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 (World Health Organization), of which 182 ended in death. All were isolated cases, except for an outbreak in a village in Algeria (the first in fifty years), 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 57 died. [
1]
There has not been a plague
epidemic (i.e an outbreak affecting a larger area) for many years.
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,
squirrels and other similar large rodents.
Human infection most often occurs when a person is bitten by a
rat flea (
Xenopsylla cheopis) 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 can not 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, 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 (who had also come to China to battle the Third Pandemic) 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 (Taiwan), 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.
Depending on the symptoms and the route of infection, plague appears in several forms, classified by the WHO with different codes::Main disease::(A20)
Plague (
Pestis). Infections caused by
Yersinia pestis.:Forms:: (A20.0)
Bubonic plague (
Pestis bubonica) occurs when
Yersinia pestis causes an inflammation of the
lymph nodes, making them tender and swollen (from lat.
bubo = bump). This is the most common form of plague.:(A20.1)
Cellulocutaneous plague (
Pestis cellulocutanea) is a very unusual form, with
Yersinia pestis causing a skin infection.:(A20.2)
Pneumonic plague or
pulmonic plague (
Pestis pneumonica) 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.: (A20.3)
Meningeal plague or
plague meningitis (
Pestis meningealis) 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.: (A20.?)
Pharyngeal plague occurs when
Yersinia pestis is consumed, often through food. It can resemble
tonsillitis. Very rare form.: (A20.7)
Septicemic plague (
Pestis septic(h)aemica) 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.:(A20.8)
Other forms of plague (
Aliae formae pestis) 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.
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%.
An Indian doctor of Russian-Jewish origin
Vladimir Havkin was the first who invented and tested an anti-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 (not suitable for children)
More recently,
*
Gentamicin 2.5 mg/kg
IV or
IM twice daily for 7 days
*
Doxycycline 100 mg (adults) or 2.2 mg/kg (children) orally twice dailyhave also been shown to be effective.
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 (430 B.C.),
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 (Speilvogal, J, 1999, pp. 56). 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. (ref. Simpson, W.J., Patrick, A.)
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 (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
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 (according to some estimates) 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 (see above), leading in time to modern treatment methods.
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.
 |
Worldwide distribution of plague infected animals 1998 |
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 (including the island of
Madagascar); 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.
* On
15 September,
2005,
ABC News reported[
2] 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[
3] 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[
4] reported a case of plague found in a
cat.
*
"There have been 242 cases of human plague in New Mexico since 1949 with 30 deaths."[
5]
* 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.
[DR Congo 'plague' leaves 100 dead, BBC News, 14 June 2006]*
The Decameron by
Giovanni Boccaccio (1350). Takes place in Florence in
1348, during the outbreak of the "
Black Death", widely believed to be Bubonic Plague.
*
A Journal of the Plague Year by
Daniel Defoe (1722). A fictional first hand account of the
London outbreak of
1665.
*
The Masque of the Red Death (1842) by
Edgar Allan Poe includes a vivid description of pestilence conventionally agreed to be septicemic plague.
*
I Promessi Sposi (
The Betrothed) (1842) by
Alessandro Manzoni 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.
*
The Plague by
Albert Camus (1947) 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 (1977) 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 (1992). 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 by
Kim Stanley Robinson (2002). 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.
*
Year of Wonders: A Novel of the Plague by
Geraldine Brooks (2002). Based on a historical village (see
Eyam) whose denizens quarantined themselves to avoid further spread of the disease.
*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 (2001).
Small Rodents Fleas from the Bubonic Plague Focus Located in the Serra dos Ã"rgãos Mountain Range, State of Rio de Janeiro, Brazil.
Memórias do Instituto Oswaldo Cruz 96(5), 603–609. PMID 11500756.
this manuscript reports a census of potential plague vectors (rodents and fleas) in a Brazilian focus region (i.e. region associated with cases of disease); 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 0684153726.
* 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 0060006927.
* McNeill, William H.
Plagues and People. New York: Anchor Books, 1976. ISBN 0385121229. 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 0743236858.
* 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 0534560628.
* ABC News,
Plague Infected Mice Missing From N.J. Lab,
2005-09-15Numbered references
*
Plague (disambiguation page)*
Black Death*
Epidemic*
Medieval demography*
Plague of Justinian*
Third Pandemic*
Ring around the rosey*
List of Bubonic plague outbreaks*
Plague columns*
Plague doctor*
World Health Organization**
Health topic**
Communicable Disease Surveillance & Response - Impact of plague & Information resources
*
Centers for Disease Control and Prevention**
CDC Plague map world distribution, publications, information on bioterrorism preparedness and response regarding plague
**
Infectious Disease Information more links including travelers' health
*
Symptoms, causes, pictures of bubonic plague*
Bubonic Plague Timeline
*
Secrets of the Dead . Mystery of the Black Death PBS
