Could the plague have been transmitted by humans?

The Black Death was primarily transmitted through the bites of infected fleas that lived on black rats. These rats likely originated in Central Asia and spread west along trade routes, reaching Europe by the mid-1300s. Transmission could also occur if an infected flea bit a human or if an infected person's bodily fluids, such as blood or phlegm, came into contact with an open wound on another person. In these cases, the plague was known as "pneumonic plague" and could spread from person to person without the involvement of fleas. Additionally, while rare, transmission could also occur through the direct handling of infected animals or their carcasses.