1.1 Characteristics of Respiratory Infectious Disease Transmission Respiratory infectious diseases are caused by pathogens entering the body through the respiratory tract, such as the throat, nasal cavity, trachea, or bronchi, leading to a series of contagious respiratory diseases. Common traditional respiratory infectious diseases (such as influenza) and emerging respiratory infectious diseases (such as COVID-19, SARS, MERS, etc.) are mainly transmitted through respiratory droplets and contact, and there is also the possibility of aerosol transmission. They are characterized by complex transmission routes, wide transmission ranges, and universal susceptibility among populations, making them prone to outbreaks and epidemics, and difficult to control.

1.2 The Role of Air in the Transmission of Respiratory Infectious Diseases Air and aerosols and droplet particles in the air are important media for the transmission of respiratory infectious diseases. The risk of cross-infection of respiratory infectious diseases is related to factors such as the patient's respiratory ventilation volume, the amount of pathogens exhaled by the patient, the size of droplets, the number of patients, the ventilation volume and air change rate of the room, exposure time, the distance between the exposed person and the patient, and whether the relevant personnel have mask protection. Strengthening ventilation can dilute the droplet nuclei exhaled by the patient, remove indoor air pollutants, reduce the concentration of pathogens, and thus reduce the risk of cross-infection of respiratory infectious diseases.

The air around the living areas of patients with respiratory infectious diseases may also be polluted and increase the risk of disease cross-transmission, which needs to be paid attention to and valued. Microbial aerosols containing pathogens can be suspended in the air, and direct inhalation through the respiratory tract can cause infection.

1.3 Air Disinfection Requirements for the Prevention and Control of Respiratory Infectious Diseases Air disinfection is an important means of cutting off the transmission routes of respiratory infectious diseases and is one of the key links in controlling the spread of respiratory infectious diseases. Taking scientific and appropriate dynamic air disinfection methods during medical activities can effectively control the occurrence of hospital infections and the cross-transmission of various respiratory infectious diseases.

2 Common Air Disinfection Methods for the Prevention and Control of Respiratory Infectious Diseases According to the requirements of national guidelines and combined with the results of domestic and foreign literature research, this article briefly introduces the common air disinfection methods for the prevention and control of respiratory infectious diseases, including the scope of application, usage methods, and effects of physical and chemical disinfection. Medical institutions and related areas can choose according to actual conditions and environmental conditions.

2.1 Physical Disinfection Ventilation Including natural ventilation and mechanical ventilation. Natural ventilation refers to the exchange of air through the density difference between indoor and outdoor air caused by thermal pressure or wind pressure.

Mechanical ventilation refers to the movement of air through the installation of ventilation equipment, using the power generated by fans and exhaust fans. Compared with natural ventilation, mechanical ventilation is not easily affected by environmental factors such as seasons, outdoor wind force, and temperature, but there are difficulties such as energy consumption, pipeline design, fan power, and cleaning and disinfection of mechanical ventilation equipment.

2.2 Chemical Disinfection Chemical disinfection is the use of chemical disinfectants that have a killing effect on pathogens, using tools to suspend them in the air to kill pathogens and achieve the purpose of preventing and controlling the spread of infectious diseases. Common chemical disinfectants effective against respiratory infectious disease pathogens include peracetic acid, chlorine dioxide, hydrogen peroxide, ozone, etc. Since chemical disinfectants generally have irritancy and corrosivity, they are suitable for air disinfection in unoccupied rooms and are often used for terminal disinfection after patient discharge in medical institutions. The hospital air purification management specification recommends using ultra-low volume spray method and fumigation method for air disinfection with chemical disinfectants.

2.3 Air Disinfection Devices Air disinfection devices can be used for indoor air disinfection when people are present and have been increasingly applied in medical institutions. The basic principle of air disinfection devices is to use the elimination factors in them to act on the air entering the air disinfection device, effectively killing the microorganisms in the air and filtering out dust particles.

3 Summary Air disinfection can effectively prevent and control the spread of respiratory infectious diseases and avoid cross-infection. During the prevalence of respiratory infectious diseases, indoor ventilation should be kept good, and centralized air conditioning ventilation systems should be used correctly. In the presence of people, natural ventilation, mechanical ventilation, or the use of air disinfection devices can be taken according to actual conditions. In the absence of people, ultraviolet irradiation disinfection can be used, or appropriate concentrations of peracetic acid, chlorine dioxide, hydrogen peroxide, and other chemical disinfectants can be selected, and air disinfection can be carried out using the ultra-low volume spray method or fumigation method.