Third plague pandemic  The third plague pandemic was a major bubonic plague pandemic that began in Yunnan, China, in 1855 during the fifth year of the Xianfeng Emperor of the Qing dynasty. This episode of bubonic plague spread to all inhabited continents, and ultimately led to more than 12 million deaths in India and China, with about 10 million killed in India alone. According to the World Health Organization, the pandemic was considered active until 1960, when worldwide casualties dropped to 200 per year. Plague deaths have continued at a lower level for every year since. The name refers to this pandemic being the third major bubonic plague outbreak to affect European society. The first began with the Plague of Justinian, which ravaged the Byzantine Empire and surrounding areas in 541 and 542; the pandemic persisted in successive waves until the middle of the 8th century. The second began with the Black Death, which killed at least one third of Europe's population in a series of expanding waves of infection from 1346 to 1353; this pandemic recurred regularly until the 19th century. Casualty patterns indicate that waves of this late-19th-century/early-20th-century pandemic may have come from two different sources. The first was primarily bubonic and was carried around the world through ocean-going trade, through transporting infected persons, rats, and cargoes harboring fleas. The second, more virulent strain, was primarily pneumonic in character with a strong person-to-person contagion. This strain was largely confined to Asia, in particular Manchuria and Mongolia. The bubonic plague was endemic in populations of infected ground rodents in central Asia and was a known cause of death among the migrant and established human populations in that region for centuries. An influx of new people because of political conflicts and global trade led to the distribution of the disease throughout the world. A natural reservoir or nidus for plague is in western Yunnan and is still an ongoing health risk. The third pandemic of plague originated in the area after a rapid influx of Han Chinese to exploit the demand for minerals, primarily copper, in the second half of the 19th century. By 1850, the population had exploded to over 7 million people. Increasing transportation throughout the region brought people in contact with plague-infected fleas, the primary vector between the yellow-breasted rat ("Rattus flavipectus") and humans. People brought the fleas and rats back into growing urban areas, where small outbreaks sometimes reached epidemic proportions.