November 10, 2007
York, a 37 year-old wildlife biologist at Arizona's Grand Canyon National Park
was found deceased in his residence on the South Rim. York had became ill on
October 30 and had called into work sick for a couple of days. His body was
discovered on November 2nd.
Centers for Disease Control and Prevention (CDC)
has confirmed plague as the cause of his death. this testing confirmed
preliminary laboratory tests conducted by the Arizona Department of Health
Services (ADHS) and the
Plague is a rare, but sometimes fatal, disease caused by the bacterium Yersinia pestis. It is primarily a disease of animals, but it can be
transmitted to humans through the bites of rodent fleas or by direct contact
with infected animals.
York grew up in Shelburne, Massachusetts and graduated from Mohawk Trail
Regional High School. He earned an undergraduate degree from the University of
Maine in 1992, and a master's from University of Massachusetts.
York was working with the cougar collaring program and had been at the
Grand Canyon for about two years. Though the source of his infection is not
certain, York most likely became infected with plague from a
mountain lion he had skinned and preformed a necropsy on three days before he
became ill. That cougar later tested
positive for the same strain of plague.
were consistent with pneumonic plague, the most serious but least common form
of plague. In rare cases, pneumonic plague can spread person to person through
aerosolized respiratory droplets (e.g. coughing, sneezing). However, according to the
CDC, transmission of plague from person to person has not been observed in the
United States since 1924.
Since pneumonic plague was initially suspected as a possible cause of
York’s death, the National Park Service worked with the Grand Canyon Clinic to
offer a seven-day course of prophylactic antibiotics to persons who had close
contact (within six feet) with York while he was symptomatic. About 50 people
have been contacted and are in the process of receiving medication. Close
contacts of York have also been informed to watch for symptoms consistent with
plague and to seek medical attention as soon as possible if symptoms develop.
Symptoms of pneumonic plague include fever, headache, chest pain, cough, and
bloody saliva. Early treatment with antibiotics is essential to surviving
Plague is considered endemic in northern Arizona at elevations above 4,500
feet. While an average of one or two human cases of plague are reported each
year in Arizona, there were no human cases reported from 2001 through 2006 in
Increased plague activity in Arizona was reported in 2007 to public
health officials: one human case, who survived, was reported in Apache County;
prairie dog colony die-offs in two separate neighborhoods in Flagstaff
(Coconino County) were confirmed to be from plague; and
a domestic pet cat from north of Prescott (Yavapai County) was also documented
as infected with plague.
York had direct contact with both wild rodents and mountain lions, which
put him at a higher risk for plague than other park staff and the general
Persons living, working, or visiting areas where plague is known to be
present can take the following precautions to reduce their risk of exposure:
- Do not handle sick or dead animals.
- Prevent pets from roaming loose.
- Control fleas on pets with flea collars or flea sprays routinely.
- Avoid exposure to rodent burrows and fleas and wild animals.
- Use insect repellant when visiting or working in areas where plague
might be active or rodents might be present.
- Wear rubber gloves when cleaning or skinning wild animals.
- Domestic cats are susceptible to plague. Cat owners should take their
ill cats to a veterinarian for evaluation.