Novel Coronavirus Pneumonia Susceptible Population Population is generally susceptible. Novel coronavirus pneumonia can occur in both immunocompromised and immunocompetent people, depending on the amount of virus exposure. Even immunocompetent people may become ill if they are exposed to a large amount of virus at one time. In immunocompromised people, such as the elderly, pregnant women, or those with liver or kidney dysfunction, the disease progresses relatively quickly and with greater severity. Whether or not a person becomes infected depends largely on exposure, and it is not the case that a person with a high level of resistance will have a lower risk of becoming infected. Children have less exposure and are less likely to become infected; older people, people with chronic illnesses, and people with poor resistance are more likely to become infected with the same amount of exposure. Routes of transmission of novel coronavirus pneumoniaNew coronavirus pneumonia does spread from person to person. Based on what is known, the main modes of transmission are via droplet transmission, contact transmission (including self-inoculation due to hand contamination), and close proximity transmission by respiratory aerosols of different sizes. Droplets from sneezing, coughing, and talking of infected persons, which carry the novel coronavirus, can be inhaled directly by close contact, leading to infection. In addition, when the droplets with the virus are sown in the air, they may be deposited on the ground, tables, chairs and other daily necessities above, when normal people touch the contaminated items with their hands, they will be easily infected, and through contact with their own mucous membranes of the oral cavity, nasal cavity, eyes and so on, they can cause infection. What is droplet transmission droplets: it is generally believed that water-containing particles with a diameter of >5um droplets can enter the susceptible mucosal surfaces through a certain distance (generally 1 meter). Due to the large size of droplet particles, they do not remain suspended in the air for long periods of time. Respiratory droplet production: (1) coughing, sneezing or talking; (2) the implementation of the respiratory tract invasive operations, such as suctioning or bronchoscopy, endotracheal intubation or turning, back patting and other stimulation of coughing process and cardiopulmonary resuscitation, etc.. Pathogens transmitted through droplets: influenza virus, SARS coronavirus, adenovirus, rhinovirus, mycoplasma, group A streptococcus and meningococcus (Neisseria). What is airborne i.e. aerosol transmission. Airborne particles: Generally considered to be particles <5um in diameter that remain infectious after prolonged long-distance dispersal. Airborne pathogens can also be transmitted by contact. Airborne pathogens are: exclusively airborne: Mycobacterium tuberculosis, Mycobacterium avium. Multiple routes, but predominantly airborne: measles virus, varicella zoster virus. Usually by other routes: but airborne in special circumstances (e.g., aerosol-producing maneuvers-tracheal intubation/incision, open airway suctioning), smallpox virus, SARS coronavirus, influenza virus, and norovirus. What is contact transmission Direct contact: pathogens are transmitted through direct contact with mucous membranes or skin (1) blood or blood-carrying bodily fluids enter the body through mucous membranes or broken skin (mainly seen in the transmission of viruses); (2) transmission is caused by direct contact with secretions containing certain pathogens, e.g., scabies. Indirect contact: infectious agents spread through contaminated objects or people The pathogens of enteric infectious diseases are mostly spread through indirect contact. (1) MRSA (benzoxazole/methicillin-resistant Staphylococcus aureus) (2) VRE (vancomycin-resistant enterococci) (3) C. difficile (Clostridium difficile) If you feel that you are infected with a novel coronavirus, what to do You should go to the local designated healthcare organization for examination and diagnosis in a timely manner. Suspected of being infected with the new coronavirus, when seeking medical treatment, should truthfully and in detail about the disease and the process of medical treatment, in particular, should inform the doctor of the recent history of travel and residence in Wuhan, the history of contact with patients with pneumonia or suspected patients, the history of contact with animals, etc.. Particular attention should be paid to the fact that surgical masks should be worn throughout the consultation process to protect themselves and others. References [1] Hubei Technical Publishing House, "Handbook for Prevention of New Coronavirus Pneumonia" [2] Life Times, "Epidemic Questions and Answers