Health officials reportedly confirmed on July 5 that a herdsman in the northern Chinese region of Inner Mongolia has been diagnosed with bubonic plague. The New York Times reported that the Bayannur city health commission said the man is hospitalized and in stable condition.
This is the disease that caused the Black Death pandemic in the Middle Ages, killing an estimated 50 million people across Europe. According to the World Health Organization (WHO), plague is an infectious disease caused by the Yersinia pestis bacteria, which is usually found in small mammals — namely rodents — and their fleas. In Inner Mongolia, the host is likely to be rural-living marmots, who are in the squirrel family, The New York Times reports.
"Humans can be contaminated by the bite of infected fleas, through direct contact with infected materials, or by inhalation," the WHO stated. Bubonic plague specifically is most often transmitted through an infected flea bite, and symptoms include fever, headache, chills, weakness, and swollen or painful lymph nodes, according to the CDC. Most importantly, the CDC noted that the only form of plague that can be transmitted by close human to human contact is pneumonic plague through respiratory droplets, in which patients rapidly develop pneumonia. There is also septicemic plague, infection of the blood, which can result from a flea bite or handling an infected animal. When left untreated, bubonic plague can become septicemic or pneumonic.
Pneumonic plague is the most serious form of plague, the CDC stated, and though antibiotics have greatly reduced mortality, plague can still be fatal. For bubonic plague specifically, the fatality rate is overall lower than for septicemic or pneumonic plague cases — according to WHO, bubonic plague is fatal in about 30 percent to 60 percent of cases.