A bubonic plague smear, prepared from a lymph removed from an adenopathic lymph node, or bubo, of a plague patient, demonstrates the presence of the Yersinia pestis bacteria that causes the plague. (Centers for Disease Control and Prevention/Getty Images)
PORTLAND, Ore. -- Health officials have confirmed that an Oregon man has the plague after he was bitten while trying to take a dead rodent from the mouth of a stray cat.
The unidentified Prineville, Ore., man was in critical condition on Friday. He is suffering from a blood-borne version of the disease that wiped out at least one-third of Europe in the 14th century -- that one, the bubonic plague, affect lymph nodes.
There is an average of seven human plague cases in the U.S. each year. A map maintained by the Centers for Disease Control and Prevention shows that most cases since the 1970s have been in the West, primarily the Southwest.
The plague bacteria cycles through rodent populations without killing them off; in urban areas, it's transmitted back and forth from rats to fleas. There's even a name for it -- the "enzootic cycle."
The bacteria thrive in forests, semi-arid areas and grasslands, which plague-carrying rodents from wood rats to rock squirrels call home.
Once a coin flip with death, the plague is now easier to handle for humans in the U.S. The national mortality rate stood at 66 percent before World War II, but advances in antibiotics dropped that rate to its present 16 percent.
Central Oregon health officials don't blame the cat.
"The reality is that, in rural areas, part of the role of cats is to keep the rodent population controlled around our homes and barns," said Karen Yeargain of the Crook County Health Department.
The Prineville man, who is in his 50s, remained in critical condition Friday at a Bend hospital. His illness marks the fifth case of plague in Oregon since 1996.
State public health veterinarian Dr. Emilio DeBess said the man was infected when he was bitten by the stray his family befriended. The cat died and its body is being sent to the CDC for testing.
DeBess has collected blood samples from two dogs and another cat that lives with the man's family. DeBess also collected blood samples from neighbors' pets and from animals in the local shelter to determine whether the area has a plague problem.
More than a dozen people who were in contact with the sick man have been notified and are receiving preventive antibiotics.