Colds are contagious among children. Most infections are caused by viruses, such as influenza virus, parainfluenza virus, rhinovirus, respiratory syncytial virus, etc., and a few are caused by bacterial infections, such as Haemophilus influenzae, Streptococcus haemolyticus, and Pneumococcus pneumoniae, etc. Both viruses and fine are contagious. Both viruses and bacteria are contagious, and there are two ways of spreading colds: 1) respiratory droplet transmission, in which the patient sneezes, blows his nose, coughs, and spreads the virus in the air, and then spreads it to the normal population in the form of droplets. 2) contact transmission, in which the normal population is infected through contact with the infected objects of the patient.