<P> The scale of death and social upheaval associated with plague outbreaks has made the topic prominent in a number of historical and fictional accounts since the disease was first recognized . The Black Death in particular is described and referenced in numerous contemporary sources, some of which, including works by Chaucer, Boccaccio, and Petrarch, are considered part of the Western canon . The Decameron, by Boccaccio, is notable for its use of a frame story involving individuals who have fled Florence for a secluded villa to escape the Black Death . First - person, sometimes sensationalized or fictionalized, accounts of living through plague years have also been popular across centuries and cultures . </P> <P> Later works, such as Albert Camus's novel The Plague or Ingmar Bergman's film The Seventh Seal have used bubonic plague in settings, such quarantined cities in either medieval or modern times, as a backdrop to explore a variety of concepts . Common themes include the breakdown of society, institutions, and individuals during the plague, the cultural and psychological existential confrontation with mortality, and the allegorical use of the plague in reference to contemporary moral or spiritual questions . </P> <P> Some of the earliest instances of biological warfare were said to have been products of the plague, as armies of the 14th century were recorded catapulting diseased corpses over the walls of towns and villages to spread the pestilence . </P> <P> Later, 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 . During the Khabarovsk War Crime Trials, the accused, such as Major General Kiyashi Kawashima, testified that, in 1941, 40 members of Unit 731 air - dropped plague - contaminated fleas on Changde . These operations caused epidemic plague outbreaks . </P>

When was the last known case of the bubonic plague