Infectious diseases in China are mainly divided into three categories, as follows: 1) Class A infectious diseases, including plague and cholera; 2) Class B infectious diseases, including infectious atypical pneumonia, AIDS, viral hepatitis, poliomyelitis, measles, rabies, epidemic encephalitis B, dengue fever, anthrax, dysentery, typhoid fever, whooping cough, scarlet fever, brucellosis, gonorrhea, schistosomiasis, malaria and syphilis; 3) Class C infectious diseases, including influenza, mumps, rubella, acute hemorrhagic conjunctivitis, leprosy, epidemic and endemic typhus, black fever and borreliosis.