There are three main ways of transmission of plague, which are introduced as follows: First, it can be transmitted through the respiratory tract, especially glandular plague and pneumonic plague, which are very contagious when transmitted through the respiratory tract. Secondly, when a plague-stricken animal is bitten by fleas and then bites a person, the plague bacillus will be brought into the bloodstream of the human body and infected with plague. Thirdly, plague can also be contracted after contact with plague bacilli after mistakenly eating an animal infected with plague. Plague is classified as a Class A infectious disease under the National Infectious Disease Control Law. Class A infectious diseases spread widely and quickly and need to be reported and controlled in the shortest possible time. Since plague can cause severe and life-threatening sepsis, it is important to cut off the transmission of plague.