Should You Worry About Bubonic Plague?

Centuries before the coronavirus pandemic, the Black Death swept through Europe killing perhaps half its population. Given the deadly result of that 14th-century pandemic, it is not surprising that even a single case raises fears.

However, those fears shouldn’t be overblown. Bubonic plague, which is caused by the bacterium Yersinia pestis, is a rarity today. In any given year, only a handful of cases are reported in the United States and most people recover from infection.

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A case of plague was confirmed on Feb. 7 in Oregon, about 200 miles southeast of Portland. Deschutes County Health Services issued a press release saying that a local resident had likely been infected by their symptomatic pet cat. The case — the first in the state since 2015 — was caught early and does not pose a threat to the community, according to health officials.

“All close contacts of the resident and their pet have been contacted and provided medication to prevent illness,” Richard Fawcett, M.D., the county’s health officer said.

How plague is transmitted

The most common animals to carry plague in Central Oregon are squirrels and chipmunks, but mice and other rodents can also carry the disease. In other parts of the western United States, wood rats, prairie dogs, voles and rabbits may also be infected with the bacterium. These infected animals and their fleas serve as long-term reservoirs for the bacteria.

Plague bacteria are most often transmitted to humans when they are bitten by an infected flea that can come from a wild animal or can be carried into your home by a pet that has been exposed to a wild animal outdoors. It is also possible to get infected by handling a dead animal that carries the plague, according to the CDC.

It is possible for a person who has plague to spread it to others through cough droplets. However, the last known case in the United States occurred in 1924. Human-to-human transmission still happens with some frequency in developing countries, according to the CDC.