A couple from China's remote Inner Mongolia Province traveled to Beijing earlier this week seeking treatment for symptoms including fever, chills, nausea and vomiting. On Tuesday, Chinese officials confirmed that the couple had a pneumonic plague, a serious form of the so-called "Black Death" that decimated European and African populations during the 1300s.
Unlike the better known bubonic plague, which is transmitted primarily to humans through contact with infected animals, such as fleas, pneumonic plague can be transmitted from person to person by the airborne particles in an infected human's cough, in the same way as the cold .
Left untreated, pneumonic plague is always fatal, causing death within 48 to 72 hours. But "antibiotic treatment is effective against plague bacteria, so early diagnosis and early treatment can save lives," according to the World Health Organization. "The recovery rate is high if detected and treated on time (within 24 hours of the onset of symptoms)," WHO noted.
On Weibo, a Chinese social media platform often compared to Twitter, a hashtag "confirming Beijing to treat plague cases" emerged – and quickly subsided – after news broke, according to CBS.
"I just want to know how these two came to Beijing ?? By train, airplane, or did they drive themselves?" Asked one user. "Bird flu during the rooster year … swine fever in the pig's year. Next year is the rat's year … the plague is coming," suggested another.
China's Center for Disease Control and Prevention issued its own message via Weibo on Wednesday: "After the two cases were found, the Beijing Weijian system has isolated the cases in good time and implemented detailed information on the case's case after entering Beijing The epidemiological investigation conducted detailed investigations of suspected vulnerable populations, conducted medical observations and preventive medications for the contacts, conducted terminal disinfection of the relevant sites and strengthened the monitoring of fever patients. "
" The risk is extremely low, "the agency added.
After the couple was diagnosed, workers at Beijing's Chaoyang Hospital replaced all chairs in the emergency room while police stood guard, according to reports from Chinese outlet Caixin Global.  "The (Chinese) National Health Commission is carrying out efforts to contain and treat the identified cases and increase surveillance," WHO Chinese Coordinator Fabio Scano told CBS News on Thursday.
On Friday, one of the patients was in "critical but not impaired" condition, while the other was in stable condition, NPR reported. The couple has been moved from Chaoyang to another unspecified hospital in Beijing.
Other countries that have experienced plague outbreaks in recent years include the Democratic Republic of Congo, Madagascar and Peru. "In Madagascar, cases of bubonic plague are reported almost every year, during the epidemic season (between September and April)," according to the WHO.