On Monday, public health officials in Morrison, Colorado announced that a squirrel had tested positive for the bubonic plague, also known as the Black Death. In a world attuned to the danger of animal reservoirs for human disease (COVID-19 appears to have leaped bat species; the plague usually leads a rodent to a person in the stomach of a flea), that story was going to generate fears. Sure enough, the plague squirrel has become famous, no doubt hoping to outshine the rodent, the pizza rat. This follows breathless reports earlier this month about a human case of plague in the city of Bayannur, China. But the threat of the plague is exaggerated and misplaced. And the squirrel’s threat lies elsewhere.
The plague has a historical history full of massive mortality. Analysis of ancient corpses suggests that an outbreak could have killed much of Europe’s population in 3000 BC. C. when people riding newly domesticated, and possibly infected, horses came from the Russian steppe and replaced them. It reappeared in the last years of the Roman Empire and ended with about 9 million people. In the 14th century, the Black Death took a third to half of the population of Europe. And then in the late 19th century and early 20sth, a global pandemic spread from Yunnan, China, to cities such as Bombay, Singapore, Buenos Aires, and San Francisco. The disease is generally harbored in rodents, such as squirrels, rats, and prairie dogs, and then spread through the flea bite.
Bubonic plague is a horrible disease. A subtitle of a report on Morrison’s unfortunate squirrel usefully notes that symptoms include “sudden high fever, chills, headache, and nausea.” That is, none of the painful pus-filled swelling in the armpits and groin, muscle cramps and seizures, gangrene, coma, and death. Without treatment, death rates can reach more than 50 percent.
But here is the good news: Most people who have a fever, chills, headache, and nausea are no suffering from bubonic plague. And even if for a 1 in much less than a million chances They are Down with the disease that helped topple empires, it’s still fine: we have a cure.
Worldwide, there were only 243 plague cases and 41 deaths in 2018. “The global incidence of human plague is the lowest reported in 30 years,” suggested the World Health Organization last year. In the U.S., plague presents a real, albeit lesser threat to humans and pets. It has been circulating in the wild in the Southwest for about a century, since the global pandemic. There are about seven human cases in the average year. (In parts of the American West, you may find signs that say, “Caution: Prairie dogs have Plague! “, Italic and exclamation mark in the original.)
As the Centers for Disease Control and Prevention point out, “Plague is a very serious disease, but it can be treated with commonly available antibiotics,” which includes streptomycin, gentamicin, levofloxacin, ciprofloxacin, doxycycline, moxifloxacin, and chloramphenicol. If you think You may have been bitten by a plague-infected flea, you can take some of these medications before any symptoms arise, and that will stop the onset of painful buboes in the first place. Additionally, CNN helpfully reported that last year a couple died of plague after eating a groundhog’s raw kidney. That suggests that part of any home security plan you develop in response to bubonic squirrel concerns should probably include “don’t eat raw squirrel guts.”
If you want rodent-related existential angst, squirrels armed with bubonic plague are far below squirrels that attack our power networks as a threat to national security. In his book Clear and current securityMichael A. Cohen and Micah Zenko report on a database of disruptive attacks against critical infrastructure systems, primarily within the United States. There were 2,436 attacks listed in mid-2018. Forty-nine percent of those attacks come from squirrels, which is 394 times the number of incidents in the database caused by humans. Headlines about a plague mortality threat similar in magnitude to that presented by paper cuts are missing from this much larger story.
Future Tense is an association of Slate, New America, and Arizona State University that examines emerging technologies, public policy, and society.