Oregon Resident Catches Rare Case of Plague, Likely From Their Cat

A resident of Oregon has been diagnosed with the plague for the first time since 2015, and according to health officials, they likely contracted the infection from their pet cat.

Richard Fawcett, a health officer in Deschutes County where the case was recorded, tells NBC News’ Aria Bendix that the person “responded very well to antibiotic treatment.”

The cat, on the other hand, became “pretty ill” and died from the infection, Emily Horton, public health program manager at Deschutes County Health Services, says to the Oregonian’s Kristine de Leon.

Other residents of Deschutes County, located roughly 200 miles southeast of Portland, face very little risk of catching the plague. The patient and their pet’s close contacts were informed about their exposure and provided medication to prevent illness, per a statement from the county health services. Fawcett tells NBC News he would be “very surprised if we see any other cases.”

Plague is a disease caused by the bacterium Yersinia pestis. During the 14th century, an outbreak of plague in Europe and Asia, called the Black Death, killed an estimated 25 million people, which would have been almost a third of the continent’s population. Today, however, modern antibiotics effectively treat the plague, according to the Centers for Disease Control and Prevention (CDC).

On average, about seven human plague cases are reported in the U.S. every year, per the CDC. These usually occur in rural and semi-rural areas in the “Four Corners” region of the Southwest, California, southern Oregon and western Nevada.

The plague bacteria is transmitted by fleas, which can infect many types of rodents. Cats are particularly susceptible and can catch the illness after eating infected rodents or being bitten by an infected flea. In the most recent case, “it’s likely [the bacteria] was transmitted to the cat directly from an infected rodent, since we don’t have many fleas in central Oregon,” Horton tells the Oregonian.

Pet cats have previously passed the plague to humans on several occasions. Humans can become infected via flea bites or by touching contaminated fluid or tissue from an infected animal.

The Oregon resident likely had bubonic plague, which represents more than 80 percent of plague cases in the U.S., according to NBC News. With bubonic plague, symptoms typically develop within two to eight days and can involve fever, headaches, chills, weakness and swollen, painful lymph nodes.

Bubonic plague can progress to septicemic plague, which can result in bleeding into organs and tissue death, as well as pneumonic plague, which can lead to pneumonia and respiratory failure, per the CDC. Pneumonic plague is the only form that can be spread between humans.

The case in Oregon “was identified and treated in the earlier stages of the disease, posing little risk to the community,” writes Deschutes County Health Services in the statement. “No additional cases of plague have emerged during the communicable disease investigation.”

To prevent spreading plague, the health department recommends avoiding contact with rodents and fleas, keeping pets on a leash outdoors and discouraging pets from hunting rodents, among other precautions. Squirrels and chipmunks are the most common animals to carry the plague in central Oregon, per Deschutes County Health Services.

“We know that there are reservoirs of bacteria naturally occurring in rodents throughout the West Coast,” Horton tells the Oregonian. “So, I’d caution people to do anything they can to protect their pets from those interactions with rodents, especially cats since they’re more known to pick up rodents.”

Will Sullivan | | READ MORE

Will Sullivan is a science writer based in Washington, D.C. His work has appeared in Inside Science and NOVA Next.