Oregon’s first case of human plague in 8 years likely came from a pet cat

This week, health authorities reported the first case of plague in Deschutes County, a rural area in Oregon, in over eight years. The infected individual is believed to have contracted the disease from their pet cat, displaying symptoms, as stated by Deschutes County Health Services.

Plague exposure typically occurs through flea bites carrying Yersinia pestis, the bacterium responsible for the disease. Household pets may become infected by hunting plague-infected rodents or being bitten by an infected flea. The transmission to humans can happen through bodily fluids or tissues, including respiratory droplets or fleas brought home by pets.

Cats, being prone to capturing rodents, are more susceptible to plague due to difficulties clearing the infection from their bodies. Although rare in dogs, instances have been reported, such as in 2014 when four plague cases were linked to an infected pit bull terrier in Colorado.

Dr. Richard Fawcett, a health officer, described the recent case involving a sick cat with a draining abscess, indicating a substantial infection. The owner’s infection likely began as bubonic plague, progressing to the bloodstream upon hospitalization. Antibiotics proved effective, though there were concerns about potential pneumonic plague development.

Precautionary measures, including antibiotic treatment for close contacts, were implemented. Prior to this case, Oregon’s last human plague case was in 2015, where a teenage girl likely got infected during a hunting trip.

The U.S. averages about seven human plague cases annually, primarily in the rural West, notably in specific regions like northern New Mexico, northern Arizona, southern Colorado, California, southern Oregon, and western Nevada. The Four Corners region is identified as a hotspot.

Despite sporadic cases in central Oregon, the reasons remain unclear, with a lack of flea issues or rodent carriers. Plague tends to occur in semi-arid forests and grasslands, with advice for pet owners in affected areas to use flea control, leash pets outdoors, and seek veterinary care if illness follows rodent contact.

Bubonic plague, the most common form, is easily treatable with antibiotics if diagnosed early. Without timely treatment, it can progress to septicemic plague, causing bloodstream infections. Untreated infections may lead to pneumonic plague, often fatal, either through the progression of bubonic or direct inhalation of infectious droplets.

Despite the different forms coexisting and uncertain transitions between stages, health authorities express confidence in low general risk, emphasizing close monitoring of contacts to mitigate community risk in Deschutes County.