Plague, was a term that was applied in the Middle Ages to all fatal epidemic diseases, but now it is only applied to an acute, infectious, contagious disease of rodents and humans, caused by a short, thin, gram-negative bacillus. In humans, plague occurs in three forms:bubonic plague, pneumonic plague, and septicemic plague. The best known form is the bubonicplague and it is named after buboes, or enlarged, inflamed lymph nodes, which arecharacteristics of the plague in the groin or neck or armpit. Bubonic plague can only betransmitted by the bite of any of numerous insects that are normally parasitic on rodents and thatseek new hosts when the original host dies. If the plague is left untreated it is fatal in thirty toseventy five percent of all cases. Mortality in treated cases is only five to ten percent.History Of The Bubonic PlagueThe origin of the bubonic plague is unknown but it may have started in Africa or India.Colonies of infected rats were established in Northern India, many years ago. Some of theserodents had infected traders on the route between the Middle East and China. After 1330 theplague had invaded China. From China it was transferred westward by traders and Mongolarmies in the 14th century. While these traders were travelling westward they followed a morenortherly route through the grasslands of what is now Russia, thus establishing a vast infectedrodent population there.In 1346 the disease reached Crimea and found its way to Europe in 1347. Theoutbreak in Europe was a devastating one, which resulted in more than 25 million deaths-abouttwenty five percent of the continent's whole population. After that the plague reappearedirregularly in many European cities until the early 18th century, when it suddenly stopped there.No explanation has ever been given for the plague's rapid disappearance.Symptoms and CausesThe first symptoms of the bubonic plague are headache, vomiting, nausea, aching jointsand a feeling of ill he...
