Who is the affected population of Bubonic Plague?

Bubonic plague primarily affects humans, although other mammals such as rodents, squirrels, rats, and cats are also susceptible to infection. The bacterium that causes bubonic plague, _Yersinia pestis_, is usually transmitted to humans through the bites of infected fleas. The fleas acquire the bacteria when they feed on infected animals, such as rodents, and then transmit the bacteria to humans when they bite them. Bubonic plague can also be transmitted through direct contact with infected animals or their bodily fluids.

Historically, bubonic plague has caused several major pandemics, the most famous being the Black Death that swept through Europe in the 14th century, causing the death of an estimated 75-200 million people. In modern times, bubonic plague is still present in some parts of the world, but it is much less common and can usually be effectively treated with antibiotics.