world virtually every year between 1500 and 1850. plague repeatedly struck the cities of north africa. algiers lost 30,000–50,000 to it in 1620–1621, and again in 1654–1657, 1665, 1691, and 1740–1742. plague remained a major event in ottoman society until the second quarter of the 19th century. between 1701 and 1750, 37 larger and smaller epidemics were recorded in constantinople, and 31 between 1751 and 1800. baghdad has suffered severely from visitations of the plague, and sometimes two-thirds of its population has been wiped out. third pandemic: 19th and 20th centuries houses being burned in china in the 1890s during the bubonic plague pandemic paul-louis simond injecting a plague vaccine in karachi, 1898 the third pandemic began in china's yunnan province in 1855, spreading plague to all inhabited continents and ultimately killing more than 12 million people in india and china alone. casualty patterns indicate that waves of this pandemic may have come from two different sources. the first was primarily bubonic and was carried around the world through ocean-going trade, 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 manchuria and mongolia. researchers during the "third pandemic" identified plague vectors and the plague bacterium (see above), leading in time to modern treatment methods. plague occurred in russia in 1877–1889 in rural areas near the ural mountains and the caspian sea. efforts in hygiene and patient isolation reduced the spread of the disease, with approximately 420 deaths in the region. significantly, the region of vetlianka in this area is near a population of the bobak marmot, a small rodent considered a very dangerous plague reservoir. the last significant russian outbreak of plague was in siberia in 1910 after sudden demand for marmot skins (a substitute for sable) increased the price by 400 percent. the traditional hunters would not hunt a sick marmot and it was taboo to eat the fat from under the arm (the axillary lymphatic gland that often harboured the plague) so outbreaks tended to be confined to single individuals. the price increase, however, attracted thousands of chinese hunters from manchuria who not only caught the sick animals but also ate the fat, which was considered a delicacy. the plague spread from the hunting grounds to the terminus of the chinese eastern railway and then followed the track for 2,700 km. the plague lasted 7 months and killed 60,000 people. the bubonic plague continued to circulate through different ports globally for the next fifty years; however, it was primarily found in southeast asia. the 1894 hong kong plague had particularly high death rates, 90%. as late as 1897, medical authorities in the european powers organized a conference in venice, seeking ways to keep the plague out of europe. mumbai plague epidemic struck the city of bombay (mumbai) in 1896. the disease reached the territory of hawaii in december 1899, and the board of health's decision to initiate controlled burns of select buildings in honolulu's chinatown turned into an uncontrolled fire which led to the inadvertent burning of most of chinatown on january 20, 1900. shortly thereafter, plague reached the continental us, initiating the san francisco plague of 1900–1904. plague persisted in hawaii on the outer islands of maui and hawaii (the big island) until it was finally eradicated in 1960. research done by a team of biologists from the institute of pasteur in paris and johannes gutenberg university mainz in germany by analyzing the dna and proteins from plague pits, published in october 2010, reported beyond doubt that all 'the three major plagues' were due to at least two previously unknown strains of yersinia pestis and originated from china. a team of medical geneticists led by mark achtman of university college cork in ireland reconstructed a family tree of the bacterium and concluded in an online issue of nature genetics published on 31 october 2010 that all three of the great waves of plague originated from china. modern cases distribution of plague infected animals and people, as of 1998. plague cases were massively reduced during the second half of the 20th century, but outbreaks still occurred, especially in developing countries. between 1954 and 1997, human plague was reported in 38 countries, making the disease a re-emerging threat to human health. between 1987 and 2001, 36,876 confirmed cases of plague with 2,847 deaths are reported to the world health organization. in the 21st century, fewer than 200 people die of the plague worldwide each year, mainly due to lack of treatment. plague is considered to be endemic in 26 countries around the world, with most cases found in remote areas of africa. the three most endemic countries are madagascar, the democratic republic of the congo and peru. outbreaks with dozens of deaths occurred in madagascar in 2014 and 2017, in india in 1994, and congo in 2006. during 1995, plague was confirmed in the united states from nine western states. currently, five to 15 people in the united states are estimated to catch the disease each year — typically in western states. the reservoir is thought to be mice. in the u.s., about half of all fatal cases of plague since 1970 have occurred in new mexico. there were two plague deaths in the state in 2006, the first fatalities in 12 years. in new mexico, four people were diagnosed with the plague in 2015; one died. in 2016, four were diagnosed and all were treated with success. three others were diagnosed by late june in 2017. vegetation such as pinyon and juniper trees are thought to support rodents such as the prairie dog and rock squirrel, with their fleas, according to paul ettestad of the new mexico public health department. as well, pets can bring back fleas from dead rodents, he said. the cdc indicates that over the past century, plague in the u.s. has been most common in the areas of northern new mexico, northwestern arizona and southern colorado. there was an outbreak of the bubonic plague in the nyimba district of eastern zambia in 2015. epidemiologists estimated a basic reproduction number of 1.75 with a 95 percent confidence interval ranging from 1.51 to 1.98. this is almost certainly substantially lower than how the plague propagated during the black death pandemic of the fourteenth century with the with living conditions and existing genetic diversity in the human population at that time.