Bubonic plague Guide, Meaning , Facts, Information and Description
Bubonic plague is an infectious disease that is believed to have caused several epidemics or pandemics throughout history. Bubonic plague is the most common form of plague which causes swollen, tender lymph glandss (called buboes); other forms are Septicemic plague which occurs when plague bacteria multiply in the blood and Pneumonic plague which occurs when the lungs are infected.
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2 Symptoms and treatment 3 Historical cases 4 Contemporary cases 5 In Literature 6 See also 7 External links |
Infection
It 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 occurs when people come into contact with infected rodents.
The disease is caused by the bacterium Yersinia pestis and is usually transmitted by the bite of fleas from an infected host, often a black rat. The bacteria are transferred from the blood of infected rats to the rat flea (Xenopsylla cheopsis). The bacillus multiplies in the stomach of the flea, blocking it. When the flea next bites a mammal, the consumed blood 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.
Symptoms and treatment
The 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 infect the bloodstream (septicemic plague) and then the lungs (pneumonic plague).
In septicemic plague there is bleeding into the skin and other organs, which creates black patches on the skin, hence the name Black Death. Untreated septicemic plague is universally fatal, but early treatment with antibiotics is effective (usually streptomycin or gentamicin), reducing the mortality rate to around 15% (USA 1980s). People who die from this form of plague often die on the same day that symptoms first appear.
With pneumonic plague the infected lungs raised the possibility of person-to-person transmission through respiratory droplets. The incubation period for pneumonic plague is usually between two to 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%. The disease can be effectively treated with antibiotics, however.
As a biological weapon aerosolized pneumonic plague is the only modernly credible plague agent. However, historical accounts detail the use of infected animal carcasses to infect enemy water supplies in medieval Europe. In addition, experiments (both in the lab and the field) using the release of infected rats on the ground, and the release of infected fleas, by both aerial drop and modified explosives, have been alledged to have been conducted as recently as in the first half of the 20th century.
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Historical cases
The Plague of Justinian is the first known pandemic on record, and it also marks the first recorded case of bubonic plague in 541. At its peak, the plague was killing 10,000 people in Constantinople every day and 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.
During the mid-1300s, a massive and deadly epidemic swept through Europe, killing one-third of the population by some estimates, and subsequently changing the course of European history. Commonly referred to as The Black Death, many scientists and historians believe that this outbreak was an incidence of bubonic plague.
Bubonic plague struck parts of Europe throughout the 1400s, 1500s and 1600s with varying degrees of intensity and fatality. Researchers still do not agree on why the infection never returned to Europe after that.
The third pandemic began in China in 1855, spread to all inhabited continents, and ultimately killed more than 12 million people in India and China alone.
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 Eastern Africa; and 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.
Globally, the World Health Organization reports 1,000 to 3,000 cases of plague every year.
This is an Article on Bubonic plague. Page Contains Information, Facts Details or Explanation Guide About Bubonic plague In Literature
See also
External links
