Epidemiology of plague
Modern cases
On August 31, 1984, the Centers for Disease Control and Prevention (CDC) reported a case of pneumonic plague in Claremont, California. The CDC believed that the patient, a veterinarian, had contracted plague from a stray cat. As the cat wasn't available for necropsy, this could not be ultimately confirmed. From 1995 to 1998, annual outbreaks of plague were witnessed in Mahajanga, Madagascar. 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 February 2002, a small outbreak of pneumonic plague took place in the Shimla District of Himachal Pradesh state in northern India. In November 2002, a New Mexico couple contracted bubonic plague while visiting New York after being bitten by infected fleas in their home state. Both were treated by antibiotics, but the man developed septicemic plague which required amputation of both legs below the knee, due to gangrene caused by the lack of blood flow. After a medically-induced three-month coma, the patient survived. On April 19, 2006, CNN News and others reported a case of plague in Los Angeles, California, the first reported case in that city since 1984. In May 2006, KSL Newsradio reported a case of plague found in dead field mice and chipmunks at Natural Bridges National Monument about 40 miles (64 km) west of Blanding in San Juan County, Utah. In May 2006, Arizona media reported a case of plague found in a cat. In June 2006, one hundred deaths resulting from pneumonic plague were reported in Ituri district of the eastern Democratic Republic of the Congo. Control of the plague was proving difficult due to the ongoing conflict. It was reported in September 2006 that three mice infected with Yersinia pestis apparently disappeared from a laboratory belonging to the Public Health Research Institute, located on the campus of the University of Medicine and Dentistry of New Jersey, which conducts anti-bioterrorism research for the United States government. On May 16, 2007, an 8-year-old hooded capuchin monkey in the Denver Zoo died of the bubonic plague. Five squirrels and a rabbit were also found dead on zoo grounds and tested positive for the disease. On June 5, 2007, in Torrance County, New Mexico, a 58-year-old woman developed bubonic plague, which progressed to pneumonic plague. On November 2, 2007, Eric York, a 37-year-old wildlife biologist for the National Park Service's Mountain Lion Conservation Program and The Felidae Conservation Fund, was found dead in his home at Grand Canyon National Park. On October 27, York performed a necropsy on a mountain lion that had likely perished from the disease, and three days afterward York complained of flu-like symptoms and called in sick from work. He was treated at a local clinic but was not diagnosed with any serious ailment. The discovery of his death sparked a minor health scare, with officials stating he likely died of either plague or hantavirus, and 49 people who had come into contact with York were given aggressive antibiotic treatments. None of them fell ill. Autopsy results released on November 9, confirmed the presence of Y. pestis in his body, confirming plague as a likely cause of death. In January 2008, at least 18 people died of bubonic plague in Madagascar. On June 16, 2009, Libyan authorities reported an outbreak of bubonic plague in Tobruk, Libya. 16-18 cases were reported, including one death. On August 2, 2009, Chinese authorities quarantined the town of Ziketan, Xinghai County in Hainan Tibetan Autonomous Prefecture, Qinghai Province (Northwestern China) after an outbreak of pneumonic plague. As of this writing, three have died and ten more are ill, being treated in hospital.[needs update] On September 13, 2009, Dr. Malcolm Casadaban died following an accidental laboratory exposure to an attenuated strain of the plague bacterium. This was due to his undiagnosed hereditary hemochromatosis (iron overload). He was an associate professor of molecular genetics and cell biology and of microbiology at the University of Chicago. On 1 July 2010, eight cases of Bubonic plague were reported in humans in the District of Chicama, Peru. One 32-year-old man was affected, as well as three boys and four girls ranging in age from 8 to 14 years old. 425 houses were fumigated and 1210 guinea pigs, 232 dogs, 128 cats and 73 rabbits were given anti flea treatment in an effort to stop the epidemic. On May 3, 2012, a ground squirrel trapped during routine testing at a popular campground on Palomar Mountain in San Diego County, California tested positive for the plague bacteria. On June 2, 2012, a man in Crook County, Oregon, attempting to rescue a cat choking on a mouse, was bitten and became infected with septicemic plague. On July 16, 2013, a squirrel trapped in the Table Mountain Campgrounds of Angeles National Forest tested positive for the plague, prompting a health advisory and the closing of the campground while investigators tested other squirrels and dusted the area for plague-infected fleas. On August 26, 2013, Temir Isakunov, a teenage boy, died of bubonic plague in northern Kyrgyzstan. December 2013 reports of pneumonic plague epidemic in 5 of 112 districts of Madagascar, believed to be caused by large brush fires forcing rats into towns. On July 13, 2014, a Colorado man was diagnosed with pneumonic plague. On July 22, 2014, the city of Yumen, China, was sealed off and 151 people were put in quarantine after a man died of bubonic plague. On November 21, 2014, the World Health Organization reported that there have been 40 deaths and 80 others infected on the island of Madagascar, with the first known case in the outbreak thought to have occurred in late August 2014. On May 22, 2015, the Idaho Department of Health and Welfare reported finding plague in dead ground squirrels in 24 places south of Boise in a roughly circular area about 45 miles (72 km) across. On May 27, 2016, the department reported more ground squirrels dead of plague in about the same area. By December six cats— five from the Boise area, which is in southwestern Idaho, and one in the southeastern part of the state— were found to have plague. Four of the cats died; the other two recovered with antibiotic treatment. No human cases were reported. Health authorities warned people to stay out of the affected area and issued advice about preventing contagion in people and pets.[needs update] In New Mexico, four people were diagnosed with the plague in 2015; one died. In 2016, four others 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. In Madagascar plague resulted in deaths of over 90 persons by October 2017. While earlier cases of plague in Madagascar were mostly bubonic plague, the current cases were the more infectious pneumonic plague. In China during November 2019, four cases of plague were reported. Two of them were reported to be the more infectious pneumonic plague. In 1994, there was a pneumonic plague epidemic in Surat, India that resulted in 52 deaths and in a large internal migration of about 300,000 residents, who fled fearing quarantine.
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