Category A infectious diseases refer to the plague and cholera, in addition to Category B infectious diseases of infectious atypical pneumonia, new coronavirus pneumonia, H1N1 and human infection with highly pathogenic avian influenza need to be dealt with according to Category A infectious diseases. 1. Bubonic plague: Bubonic plague is a virulent infectious disease with strong contagiousness and high mortality rate, once diagnosed or suspected bubonic plague, it should be quickly organized to carry out close isolation and on-site treatment. 2. Cholera: Cholera is a virulent intestinal infectious disease caused by Vibrio cholerae, which is characterized by severe vomiting, diarrhea, dehydration, muscle cramps, circulatory failure, etc. The key to the treatment is to replenish fluids and to correct the water-electrolyte disorders. 3. Infectious Atypical Pneumonia: Infectious Atypical Pneumonia is caused by SARS Coronavirus, also known as Severe Acute Respiratory Syndrome (SARS), in severe cases, shortness of breath and respiratory distress will occur. The disease is self-limiting and has no specific treatment. 4. New coronavirus pneumonia: the disease is currently in an epidemic state of a respiratory infectious diseases, acute respiratory tract infection is the main manifestation of the disease. 5. H1N1: H1N1 will lead to patients with clinical symptoms of influenza A, the population is generally susceptible, and seriously ill patients will be threatened with death. 6. Human infection with highly pathogenic avian influenza: This infectious disease is caused by certain subtypes of avian influenza A virus strains. It is mainly managed through symptomatic treatment and antiviral therapy. Individuals need to recognize the seriousness of the infectious disease and should seek medical attention in a timely manner and cooperate with the relevant isolation work. Tips] In this article, “new coronavirus pneumonia” and “new coronavirus pneumonia” have been renamed to “new coronavirus infection” on December 26, 2022, as announced by the National Health Commission.