Legal basis: Article 4 of the Law of People's Republic of China (PRC) on the Prevention and Control of Infectious Diseases adopts the prevention and control measures of Class A infectious diseases as mentioned in this Law for infectious atypical pneumonia in Class B infectious diseases, pulmonary anthrax in anthrax and human infection with highly pathogenic avian influenza. If other Class B infectious diseases and infectious diseases with unknown causes need to take the measures of prevention and control of Class A infectious diseases as mentioned in this Law, the administrative department of public health of the State Council shall promptly report to the State Council for approval before promulgation and implementation.