AIDS is a class B infectious disease. At present, there are 39 statutory infectious diseases in China, which are divided into three categories, A, B and C, according to their speed of transmission and the danger to human beings, and need to be managed in a categorized manner. There are two types of Class A infectious diseases, namely plague and cholera, 26 types of Class B infectious diseases, and 11 types of Class C infectious diseases, which have different reporting time limits. Category A infectious diseases are infectious diseases under compulsory management, category B infectious diseases are strictly managed infectious diseases, and category C infectious diseases are infectious diseases under surveillance management.