The Black Death, also called The Plague, may be back, at least in parts of China. At least three cases have been reported, and many people who had contact with the infected were placed in medical quarantine to prevent a larger outbreak.
Between the years 1346 and 1353, the Black Death spread across Europe, killing 60 percent of Europe’s population. The Plague is caused by a bacterium, Yersinia pestis, which circulates among wild rodents. Humans usually get infected when they handle an infected animal, or when they're bitten by a flea that picked up the bacteria from an infected rodent.
In the United States, plague occurs in rural and semi-rural areas, especially upland forests and grasslands. A variety of mammals can be infected including wood rats, prairie dogs, chipmunks, mice, voles and rabbits. Carnivores that feed on rodents can also be infected. Infected rodents and fleas represent a reservoir for the disease.
When the infected rodent population is large enough, other animals become infected, which makes human infections more likely. Cats are very susceptible to plague, which they can acquire by eating infected rodents. Cats are known to then infect their owners or veterinarians.
The illness caused by the plague bacteria can take several forms: bubonic plague, septicemic plague or pneumonic plague. When the bacterium spreads from the bite site to the nearest lymph nodes, the nodes become inflamed, tense and painful and are called “buboes,” hence the term bubonic plague. If the infection spreads to the blood, the disease is septicemic plague.
A person with pneumonic plague has the bacteria in their lungs and can spread pneumonic plague to other people by coughing. If untreated, the septicemic and pneumonic forms of plague are deadly. Modern antibiotics and supportive care are effective, but many physicians today have little experience with plague, so diagnosis can take a while.
In 2017, there were several outbreaks of plague in Madagascar, but the most recent cases have been in China. A 59-year-old man from Xilingol League, a rural region of Inner Mongolia, was diagnosed with plague after handling a wild rabbit. He was isolated and treated at a hospital.
Twenty-eight people with whom he had close contact were placed in medical quarantine and didn't exhibit symptoms. Just days earlier, a married couple from Xilingol League had been diagnosed with pneumonic plague. These patients were evacuated and quarantined in facilities in Beijing. The source of their infection wasn't identified. The police guarded the emergency room to ensure no others would be exposed. Chinese officials have tried to contain the news of these plague cases, leaving many people concerned.
Over the last several years, China has had persistent droughts caused by climate change, which could mean that rodent populations have increased. This could be the reason behind the recent plague cases. The Chinese Health Commission reports that six people have died of the plague since 2014, but this group of recent cases has people wondering if there is a more serious outbreak occurring.