The bubonic plague is a highly infectious and fearsome disease that attacks the lungs and lymph nodes. It is also called the Black Death or black plague. The bubonic plague is caused by Pasteurella pestis, a bacteria which resides within infected fleas and rats. Victims of the bubonic plague develop early symptoms, such as shivering, vomiting, headache, intolerance to light, back and limb pain, and a white coating on the tongue. Eventually, they develop black egg-sized swellings (buboes) filled with blood and pus under the armpits and in the groin. As the disease progresses, internal bleeding leads to black patches on the skin, and the victim may die in three to five days. Invasion of the lungs by the bacterium causes an equally fatal form of the plague called pneumonic plague, which can be transmitted from person to person by air droplets and saliva.
Historical records document outbreaks of the plague as early as 430 b.c., when an epidemic struck Athens, Greece; but the most notorious bubonic plague epidemic began in Europe around 1346, reportedly when a ship of sick and dying sailors arrived at the Black Sea port of Caffa. This plague lasted four years and killed about one-third of the population of Europe, or approximately 20 million people. For hundreds of years after, epidemics of bubonic plague would sweep across the world killing millions more. The disease was so lethal that some victims supposedly would go to bed healthy and die in their sleep. When the disease raged through a town, the population would die so quickly that it was nearly impossible to bury the dead.
Other serious epidemics arose from the fourteenth to seventeenth centuries, including the Great Plague of London in 1665. The incidence of plague began to decline after that. However, major epidemics still broke out occasionally; and, once germ theory, developed largely by Louis Pasteur, had provided a basis for understanding communicable disease around the mid-1800s, a major effort could be initiated to find its cause and cure. At the end of the nineteenth century, several major researchers made important discoveries that led to the control of bubonic plague.
Japanese-born scientist Shibasaburo Kitasato had studied in Germany where he was the first to grow a pure culture of the tetanus virus. He also developed, with Emil von Behring, the theory of antitoxin immunity. When Kitasato returned to Japan from abroad in 1894, he went to Hong Kong where a major outbreak of plague was in progress, and was able to isolate its cause--a bacterium called Pasteurella pestis. Around the same time a Swiss bacteriologist, Alexandre Yersin (1863-1943), independently announced the same finding.
German bacteriologist Heinrich Hermann Robert Koch, who was the first to study bacteria in solid media and went on to identify the bacterial causes of anthrax, tuberculosis and cholera, turned his attention to bubonic plague in 1897. He determined that the disease was transmitted by a flea that infested rats; the germ lived in the stomach of the flea and the bloodstream of the rat and infected humans through the bite of either creature.
Today, immunization and antibiotics control the disease. However, occasional outbreaks of bubonic plague still occur in parts of the world where overcrowding and poor sanitation make the control of its pest carriers difficult. An outbreak of bubonic plaque in Beed, India, in 1994 is believed to have resulted from an earthquake the year before that devastated the region, causing rodents to migrate and possibly enter grain stores. Although none of the 90 reported cases were fatal, public health officials believe that this outbreak may have set the stage for virulent outbreak of pneumonic plague in Surat, India. The theory is that some of the people who developed bubonic plague in Beed progressed to the pneumonic plague stage and then passed the sickness on to people in Surat. More than 6,000 cases of pneumonic plague and 56 deaths from the disease were reported in Surat in 1994. While some investigators thought the outbreak may have been caused by different bacteria or viruses and not the plague at all, the incident points to the problems caused by overcrowding and poor sanitation.
While plague vaccines have been developed, the most effective approach to prevent the plague continues to be improved sanitary conditions, including control of rat populations and immediate isolation of plague patients when they are diagnosed. For travelers to countries that still suffer from outbreaks of the plague, prophylaxis antibiotics are recommended. Early treatment with several antibiotics, including streptomycin, significantly reduces mortality from 60 to 100 percent to 10 to 15 percent.
This is the complete article, containing 757 words
(approx. 3 pages at 300 words per page).
