Though plague is associated with events long ago and far away, for the past century the bacteria responsible for the Black Death has lived a mostly benign existence in this region.
"Someone made the comment that they didn't think we had the plague anymore," said Park Service public health officer Capt. Matt Walburger, referring to feedback he got in an informational meeting here last week.
The bacteria yersina pestis came to the U.S. around the turn of last century, through California aboard ships from Asia. It first established itself in California's ground squirrel population, moving east and spreading through dens of prairie dogs, wood rats, deer mice and wild rabbits.
Despite its prevalence in the environment, only 10-20 people in the U.S. contract plague each year. Before York's death, the last reported case in Coconino County was in 1994, said Mike Callahan, an epidemiologist with the county health department.
Most cases are transmitted by infected fleas, especially as animals die of plague and their fleas seek out new hosts. There have also been reported cases among hunters who contracted the disease while skinning animals, most commonly wildcats, which, with their domestic cousins, are exposed to the disease through their diet of rodents.
The pneumonic form, which is both the rarest and most serious form, is also transmissible from person to person (or pet to person) through cough droplets, though the last recorded instance of that was in 1924.
"Outside of the host, it's very fragile," said NPS Public Health Consultant Matt Walburger. "In dry conditions and sunlight, it might last a few minutes."
To protect against not only plague but other animal-borne infections, Park Safety Officer Don Singer advised rodent and insect control along with prudent handling of animals and animal waste.
"These are still issues in northern Arizona," said Walburger. "If there's any area of the U.S. where this can happen, it most often happens here."
For more, visit CDC on the Web at www.cdc.gov.