Plague at the Grand Canyon

A thirty-seven year old National Park Service wildlife biologist working at Grand Canyon National Park died of pneumonic plague on November 2, 2007.

The park naturalist was found dead in his residence at the South Rim of the canyon. A presumptive diagnosis of plague was made on November 8 based on polymerase chain reaction (PCR) testing conducted at the Arizona Department of Health Services Public Health Laboratory. Subsequent laboratory testing at CDC-Fort Collins confirmed Yersinia pestis as the cause of death.

Testing of an infected mountain lion that the naturalist had had recent contact with confirmed that the strains of Yersinia pestis in the lion and the human victim were identical suggesting that the mountain lion was the likely source of the human infection.

Grand CanyonPlague is endemic in Arizona at elevations greater than 4500 feet, and the Grand Canyon region is in this area of endemicity. An average of one to two human infections with plague is reported in Arizona each year. CDC investigators found no evidence of a large epizootic of plague at the Grand Canyon and suggested that the risk to the general park visitor was minimal.

The National Park Service provides more information in its press release.