Plague is an infectious disease of animals and humans caused by the bacterium Yersinia pestis. People generally contract plague through the bite of a flea that is carrying the bacterium or by handling an animal infected with the disease. Fleas carrying plague are found primarily on rodents, but can be found on several mammal species found in South Dakota (e.g. prairie dogs, coyotes, badgers, fox, and free-roaming pets). Today, human cases of plague in the USA are rare. Human patients generally have a history of exposure in rural areas. Antibiotic treatment is effective against plague, if the infected person is treated promptly. Plague can cause severe illness or death.
Historically, plague has not been a primary wildlife- or human-health concern in South Dakota. There have been NO cases of plague in humans reported in South Dakota. In 2004, this disease was documented in prairie dogs in the wild (sylvatic plague). Since that time prairie dog die-offs have been officially documented in Custer, Shannon, and Dewey Counties; unverified reports of prairie dog die-offs have come from Fall River County. Prairie dog die-offs due to plague have recently (May of 2008) been documented in the Conata Basin area of Pennington County. This area is located along Highway 44 between the towns of Interior and Scenic, SD.
Occurrence and spread of sylvatic plague and human cases of plague are being monitored by the SD Department of Game, Fish and Parks and the SD Department of Health, and several other tribal and federal wildlife and human health agencies.