Influenza A can be transmitted through droplet transmission, contact transmission, and also through direct or indirect contact with the eyes, oral cavity, nasal mucosa. 1. Droplet transmission: Influenza A can be spread by droplet inhalation through the respiratory tract; when a person with influenza A sneezes or coughs, the droplets contain a large number of influenza A viruses, and susceptible persons can be infected with influenza A when they inhale the droplets into the respiratory tract. 2. Contact transmission: susceptible persons can also be infected by influenza A virus when they come into contact with sputum, nasal mucus and other body fluids of patients with influenza A, or with objects contaminated by patients with influenza A. 3. Direct or indirect contact with mucous membranes: Influenza A virus-containing articles, droplets and secretions can be transmitted through direct or indirect contact with the mucous membranes of susceptible persons’ eyes, mouths and nasal passages, so masks should be worn, and goggles should be worn when necessary. Influenza A spreads in various ways, in crowded and closed or poorly ventilated rooms, but also through the aerosol form of transmission. During the flu season, you need to be diligent in ventilation, wear a good mask, and seek medical attention if you are not feeling well.