The article below is actually about two others that were diagnosed with the pneumonic plague in Beijing. "Pneumonic plague is one of three forms of the infectious disease and the only one that can be transmitted from person to person by inhaling infected droplets – for example, spread when someone breathes in cough droplets from an infected person." No flea needed.
From the CDC website - " Patients develop fever, headache, weakness, and a rapidly developing pneumonia with shortness of breath, chest pain, cough, and sometimes bloody or watery mucous. Pneumonic plague may develop from inhaling infectious droplets or may develop from untreated bubonic or septicemic plague after the bacteria spread to the lungs. The pneumonia may cause respiratory failure and shock. Pneumonic plague is the most serious form of the disease and is the only form of plague that can be spread from person to person (by infectious droplets)."
https://www.usatoday.com/story/news/world/2019/11/13/pneumonic-plague-tied-black-death-sickens-people-beijing-china/4176578002/
2 people in China infected with plague, the disease tied to Black Death
Ryan W. Miller
USA TODAY
11/13/19