Many are looking to historic pandemics to find answers about the COVID-19 coronavirus outbreak that has much of the world ground to a halt under quarantine and social distancing mandates. But “public health” wasn’t even a concept before one European crisis forced authorities to act: The bubonic plague or Black Death.
What does the bubonic plague pandemic of Europe and Western Asia in the 14th century tell us about pandemics more broadly, and the coronavirus contagion in particular?
Bubonic plague is widely considered the cause of the deadliest pandemic in recorded history. The world has seen at least three pandemic outbreaks of bubonic plague, according to MedicineNet author Melissa Conrad Stöppler, MD. But the worst and best-known is what we now call the ‘Black Death‘ of the mid-14th century.
“The so-called Black Death, or pandemic of the Middle Ages, began in China and made its way to Europe, causing the death of 60% of the entire population,” by some estimates, Dr. Stöppler writes.
How Did Bubonic Plague Spread?
Unlike coronavirus, most scholars agree on the cause of bubonic plague. Bubonic plague is caused by a bacterium, Yersinia pestis. However, the culprits anthrax, hemorrhagic viral fever, and louse-borne typhus have also been credibly proposed, according to Andrew Noymer, professor of public health at UC Irvine.
Unlike coronavirus, once again, bubonic plague rarely spreads directly from person to person. According to the plague theory, fleas carry the plague-causing bacteria from rodents to humans, Dr. Stöppler says.
By contrast, COVID-19 seems to spread easily from person to person.
“Although (the COVID-19 virus) is contagious, the contagious period of time remains to be determined,” writes MedicineNet author Charles Patrick Davis, MD, PhD. “Recent findings suggest it may be contagious even in the incubation period when the patient shows no symptoms.”
The plague spread widely and indiscriminately, killing young, healthy people alongside others, often in less than a week, Noymer said. That’s not like what we’ve seen from the novel coronavirus outbreak. According to the CDC, older people are more susceptible to serious symptoms, as are people with heart disease, lung disease, or diabetes.
Although there are still occasional outbreaks of bubonic plague, this disease can now be controlled using antibiotic medicine. Unfortunately, no cure or vaccine has yet been developed for COVID-19 infection, with treatment being supportive in nature, according to Dr. Davis.
Public Health Response
The coronavirus pandemic owes one of its major features to the Black Death outbreak: quarantine. But that’s not all we learned from the world’s deadliest pandemic.
The first theories of disease contagion started to appear in Europe in response to ongoing bubonic plague outbreaks. These led to new public health measures like compulsory burial and limits placed on overland movements.
In 2020 at least three cruise ships from coronavirus-stricken areas have been refused port in places like Japan, Thailand, and the Philippines out of concerns their passengers and crew might spread infection.
In similar fashion, novelist Daniel Defoe once described traveling by ship through Europe from London during the city’s Great Plague of 1665:
“The trading nations of Europe were all afraid of us,” he wrote. No port of France, or Holland, or Spain, or Italy would admit our ships.”
It was common for ports to turn away ships from plague-ridden places for extensive quarantines of as long as 40 days. Likewise, millions of people across the globe are currently bunkering down in self-isolation in an effort to curb the spread of COVID-19 coronavirus.