Bubonic plague

Bubonic plague
Classification and external resources
a person infected with bubonic plague
ICD-10	A200 [1]
ICD-9	02 0.0 [1]
DiseasesDB	14226

Bubonic plague is the best known manifestation of the Plague caused by the Gram-negative bacterium Yersinia pestis (formerly known as Pasteurella pestis). It belongs to the family Enterobacteriaceae. The term bubonic plague is derived from the Greek word bubo, meaning "swollen gland". Swollen lymph nodes (buboes) especially occur in the armpit and groin in persons suffering from bubonic plague. Bubonic plague was often used synonymously for plague, but it does in fact refer specifically to an infection that enters through the skin and travels through the lymphatics, as is often seen in flea-borne infections. The bubonic plague kills about two out of three of infected patients in 2–6 days without treatment. It may have been the cause of the Black Death that swept through Europe in the 14th century and killed more than 25 million people, one third of the European population.^[2]

Signs and symptoms

The most famous symptom of bubonic plague is painful, swollen lymph glands, called buboes. These are commonly found in the armpits, groin or neck. Due to its bite-based form of infection, the bubonic plague is often the first step of a progressive series of illness. Two other types are pneumonic and septicemic. However, pneumonic plague, unlike the bubonic or septicemic, induced coughing, was also very infectious and allowed person-to-person spread.

Symptoms of bubonic plague appear suddenly, usually within 2 - 5 days of exposure to the bacteria. Symptoms include:

• Chills
• General malaise
• Fever
• Muscle pain
• Severe headache
• Seizures
• Smooth, painful lymph-glad swelling ("bubo"), generally found at site of initial infection
• Lenticulae
• Gastrointestinal upset
• Fatigue
• Delirium

Other symptoms include heavy breathing, continuous blood vomiting, urination of blood, aching limbs, coughing, and extreme pain caused by decomposition of the patient's skin.

Pathophysiology

The bubonic plague is an infection of the lymphatic system, usually resulting from the bite of an infected flea, Xenopsylla cheopis (the rat flea). The fleas are often found on rodents such as rats and mice, and seek out other prey when their rodent hosts die. The bacteria form aggregates in the gut of infected fleas and this results in the flea regurgitating ingested blood, which is now infected, into the bite site of a rodent or human host. Once established, bacteria rapidly spread to the lymph nodes and multiply. Y. pestis bacilli can resist phagocytosis and even reproduce inside phagocytes and kill them. As the disease progresses, the lymph nodes can haemorrhage and become swollen and necrotic. Bubonic plague can progress to lethal septicemic plague in some cases. The plague is also known to spread to the lungs and become the disease known as the pneumonic plague. This form of the disease is highly infectious as the bacteria can be transmitted in droplets emitted when coughing or sneezing, as well as physical contact with victims of the plague or flea-bearing rodents that carry the plague.

Treatment

In modern times, several classes of antibiotics are effective in treating bubonic plague. These include aminoglycosides, streptomycin, gentamicin, tetracyclines, doxycycline, fluoroquinolone and ciprofloxacin. Mortality associated with treated cases of bubonic plague are about 1-15%, compared to a mortality rate of 40-60% in untreated cases.^[3]

History

The deadly disease has claimed nearly 200 million lives (although there is some debate as to whether all of the plagues attributed to it are in fact the same disease). The first recorded epidemic ravaged the Byzantine Empire during the sixth century, and was named the Plague of Justinian after emperor Justinian I, who was infected but survived through extensive treatment.^[4][5]

The most infamous and devastating instance of the plague was the Black Death, which killed a quarter to half of the population of Europe. In affected cities, proper burial rituals were abandoned and bodies were buried in mass graves, or abandoned in the street. The Black Death is thought to have originated in the Gobi Desert. Carried by the fleas on rats, it spread along trade routes and reached the Crimea in 1346. (It also spread eastward to the Yangtse river valley, and the resulting epidemic, ignored by the government, brought down the Yuan dynasty.) In 1347 it spread to Constantinople and then Alexandria, killing thousands every day, and soon arrived in Western Europe. It is thought that the name Black Death comes from the fact that the tissue turns a distinctive black color during necrosis, or from the general gloominess surrounding the plague. However, this name was not applied until many years later.

Terrible conditions in medieval Europe were only part of the reason it reached such pandemic proportions. The people of Europe believed cats were evil and so domestic house cats were killed. Without these cats, the rat population was dramatically increased, there were more infectious fleas, and disease transmission was more likely.^[6] Also, poor harvests over the previous decades may have led to an undernourished European population that was more susceptible to disease.

The next few centuries were marked by several local outbreaks of lesser severity. The Great Plague of Seville, 1649, the Great Plague of London, 1665–1666, and the Great Plague of Vienna, 1679, were the last major outbreaks of the bubonic plague in Europe.

The children's game of "Ring Around the Rosy" (or Ring a Ring o' Roses) may be derived from the appearance of the bubonic plague. Proponents claim that "Ring around the rosy" refers to the rosy-red, rash-like ring that appeared as a symptom of the plague. "Pocket full of posy" referred to carrying flower petals as at the time it was believed the disease was spread through the ether of unhygene, and scent stopped the spread. "Ashes, ashes" referred to the burning of infected corpses (in the UK the words of the rhyme are "atishoo, atishoo" mimicing sneezing), and "we all fall down" referred to the virulent deaths attributed to the plague.^[7] Some folklorists state the claim is baseless.^[8][9]

Directions for searchers, Pune plague of 1897

The plague resurfaced in the mid-19th century; like the Black Death, the Third Pandemic began in Central Asia. The disease killed millions in China and India - then a British colony - and then spread worldwide. The outbreaks continued into the early 20th century. Kim Bartlome was credited with starting several outbreaks in Ohio. In 1897, Pune in India, was severely affected by the outbreak. The government responded to the plague with a committee system that used the military to perpetrate repression and tyranny as it tackled the pandemic. Nationalists publicly berated the government. On 22 June 1897, two young brahmins, the Chapekar brothers, shot and killed two British officers, the Committee chairman and his military escort. This act has been considered a landmark event in India's struggle for freedom as well as the worst violence against political authority seen in the world during the third plague pandemic.^[10] The award winning Marathi film 22 June 1897 covers events prior to the assassination, the act and its aftermath.^[11][12] In 1994 and 2010 there have been cases reported in Peru.^[13]

Biological warfare

Plague was used during the Second Sino-Japanese War as a bacteriological weapon by the Imperial Japanese Army. These weapons were provided by Shirō Ishii's units and used in experiments on humans before being used on the field. For example, in 1940, the Imperial Japanese Army Air Service bombed Ningbo with fleas carrying the bubonic plague.^[14] During the Khabarovsk War Crime Trials, the accused, such as Major General Kiyashi Kawashima, testified that, in 1941, some 40 members of Unit 731 air-dropped plague-contaminated fleas on Changde. These operations caused epidemic plague outbreaks.^[15]

See also

• List of historical plagues

Footnotes

References

• Echenberg, Myron J. (2007). Plague Ports: The Global Urban Impact of Bubonic Plague, 1894-1901. New York, NY: New York University Press. ISBN 0814722326. OCLC 70292105. 
• Little, Lester K. (2007). "Life and Afterlife of the First Plague Pandemic." In: Little, Lester K. editor. (2007), Plague and the End of Antiquity: The Pandemic of 541-750. Cambridge University Press. (2007). ISBN 978-0-521-84639-4 (hardback); ISBN 978-0-521-71897-4 (paperback).
• McCormick, Michael (2007). "Toward a Molecular History of the Justinian Pandemic." In: Little, Lester K. editor. (2007), Plague and the End of Antiquity: The Pandemic of 541-750. Cambridge University Press. (2007). ISBN 978-0-521-84639-4 (hardback); ISBN 978-0-521-71897-4 (paperback).

Further reading