The bubonic plague might sound like an affliction of the past, but the bacterium behind the disease is still out there, causing thousands of human infections worldwide, year after year, although cases in the US are relatively rare.
The state of Oregon just confirmed its first case in eight years, and officials say it probably came from a domestic cat, which also showed symptoms.
Oregon health officer Richard Fawcett told Aria Bendix at NBC News that the patient who contracted the plague from their pet became “very sick”.
Usually, an infection of this kind starts with flu-like symptoms, including fatigue, fever, chills, and a headache.
The recent infection in Oregon, however, had progressed to the point of a draining abscess, called a “bubo”, which is a rare outcome nowadays.
Thankfully, modern antibiotics mean that the bubonic plague no longer has to be a death sentence. The bacterium behind the infection, Yersinia pestis, rarely proves fatal if caught and treated early enough.
The patient in Oregon is apparently responding well to modern medicine, and their close contacts have also been treated to curb the possibility of further spread.
Officials have not said how the infection spread from the cat to the owner, but if the cat was bitten by infected fleas, the pet might have brought the fleas home, exposing the owner, too. Either that, or the owner may have been in contact with the cat’s own contaminated fluids.
Y. pestis usually infects small mammals and fleas, and depending on how it spreads to humans, either by bites, contaminated fluids, or droplets in the air, it can cause bubonic plague or a blood- or lung-based plague.
Bubonic plague is the most common form and involves the lymphatic system, causing swollen and painful lymph nodes that can advance to open, pus-filled sores.
If the infection spreads, it can later infect the lungs as well. The patient in Oregon apparently began coughing in hospital, which is a sign that their disease may have been progressing to a dangerous stage.
The plague was first identified in the US in the early 20th century, brought to the nation via rats on ships.
The last urban plague epidemic in the country ended in 1925, but the bacteria took refuge in rural rodent species, causing periodic outbreaks outside of major cities.
Today, most cases in the US occur in rural areas of the midwest and northwest, with about seven cases reported on average each year.
The last time a case was reported in Oregon was back in 2015, when a girl was infected during a hunting trip and ended up in intensive care.
No deaths have been reported in the state from the plague in decades.
Outside of the US, the plague is present on every continent bar Oceania, and yet the places where the disease regularly occurs are those with resident animal reservoirs and overlapping human populations, such as the Democratic Republic of the Congo, Madagascar, and Peru.
During particularly bad outbreaks, the disease can claim hundreds of lives.
Still, compared to the Black Death that struck Europe in the 15th century and a 19th century outbreak in China and India that killed millions upon millions, the bubonic plague is not the international killer it once was.
Even so, thanks to its former infamy, a single case in the US can still make headlines – even when the patient is successfully treated, and the contagion stopped in its tracks.