Chinese public health authorities are taking precautions to prevent a bubonic plague outbreak in a remote northern region after a herder contracted the disease, although the risk of large-scale infections is low with the availability of modern medicine, the Washington Post reported.

The health commission in Bayannur city in the region of Inner Mongolia raised its public health warning to its third-highest of four alert levels on Sunday and banned the hunting, skinning and transportation of rodents that might carry the bacteria, known as Yersinia pestis. The municipal government raised its alert level by one notch to “standard plague outbreak alert,” which meant humans have been infected.

“There is a risk of a human plague epidemic spreading in this city,” Bayannur’s local health commission said in a statement.

Over the past year, China has reported five cases of the disease associated with some of the deadliest pandemics in human history. The plague caused the Black Death that devastated the population of medieval Europe and repeatedly afflicted Asia, but it has largely been controlled since the mid-20th century.

A World Health Organization spokeswoman in Geneva said Tuesday that the plague case count in China was low and the agency did not consider it high risk, but it was monitoring the situation, Reuters reported.

Under the new measures announced in Bayannur, which will remain in effect until 2021, suspected cases of plague among human patients or sick and dead marmots must be reported immediately. The city of Beijing also urged residents on Monday not to go camping in Inner Mongolia, a vast strip of scenic grassland and desert that urban dwellers often visit.

Because the plague and cholera are the only two diseases that fall under China’s highest classification of transmissible diseases that require the most urgent countermeasures — coronavirus is considered second-tier — parts of the northern grasslands could reenter lockdown just weeks after the country began to recover from COVID-19.

Officials at Inner Mongolia’s regional center for disease control have warned that the plague may have long been circulating locally and there is risk of human-to-human transmission and “long-distance transmission,” according to a statement posted online by the regional government last month.

The precautions against the plague are a reminder of the public health challenges facing Chinese authorities. Last week, Chinese state-affiliated researchers published a paper warning about a new type of swine flu that has been discovered in pig farmers with the potential to cause a pandemic.

So far, China’s official case numbers remain low with five plague diagnoses since last year; four patients came from Inner Mongolia and recovered normally while one man in Gansu Province died. Chinese authorities have not released details about the causes or circumstances of the cases.

In the adjacent country of Mongolia, farther north, two herders died last year after eating marmot meat and contracting the disease.

The plague, which researchers generally believe originated from the Asian steppes, killed tens or hundreds of millions of people in several deadly waves throughout history. One particularly deadly wave in the 14th century traveled along the Mongol Empire’s flourishing trading routes and killed one-third of the population in Europe in what became known as the Black Death.

The disease continues to surface periodically around the world. More than 300 cases were found in a minor outbreak in Madagascar last year, killing about 30. The plague, which is carried by rats and fleas, is usually treatable with antibiotics in its “bubonic” form, which attacks lymph nodes and causes fevers and boils. But the bacteria can kill quickly if it infects the respiratory system or bloodstream in rarer conditions known as pneumonic and septicemic plague.

The United States averages about seven cases a year, according to the Centers for Disease Control. Chinese officials say they have largely suppressed the disease since the 1950s and recorded about 30 cases in the last decade.