The plague was a highly contagious, infectious, virulent, and devastating disease due to bacteria called Yersinia pestis which mainly infects rats and other rodents that serve as the prime reservoir for the bacteria. Fleas function as the prime vectors carrying the bacteria from one species to another. The fleas bite the rodents infected with Y. pestis and then they bite people and so transmit the disease to them.
Transmission of the plague to people can also occur from eating infected animals such as squirrels (for example, in the southeastern U.S.) Once someone has the plague, they can transmit it to another person via aerosol droplets.
The word "pestilence" comes from "pestis," the Latin word for "plague." During the period of 1348-1350, the "Black Death" was responsible for the deaths of at least 1/3 the population of Europe. Because the plague was responsible for so many deaths, the plague and death have long been linked in literature. The 14th- century English poet Geoffrey Chaucer spoke of "pestilence" in "The Pardoner's Tale": "Ther cam a privee theef men clepeth Deeth, / That in this contree al the peple sleeth, / And with his spere he smoot his herte atwo, / And wente his wey withouten wordes mo. / He hath a thousand slayn this pestilence."
"La Peste" (The Plague), a novel by the Nobel Prize-winning 20th- century French writer Albert Camus, is set in the Algerian city of Oran overrun by a deadly epidemic of the plague.