What Are the Primary Routes of Transmission of Pneumonia?

There is still a good bit of scientific controversy over what are the primary routes of transmission for plague at various times and places. A study published in p n a s in 20 18 called human ecto parasites in the spread of plague in europe during the second pandemic. The authors say that, you know, if you were to have a lot of rats coming directly from humans, you would probably expect to see physical remains indicating they had been infected with plague. But there are some reasons for doubting either of these methods, was the primary route of transmission for most plague infection in the second Pandemic.