The characteristic of infectious disease is to have pathogen, have infectivity and epidemic, after infection often immunity. Some infectious diseases are also seasonal or local.
The classification of infectious diseases has not been unified, some people are classified by pathogen, some are classified by transmission route.
To prevent infectious diseases, comprehensive measures should be taken to cut off the main transmission links. The spread and prevalence of infectious diseases must have 3 links, that is, the source of infection (the person or animal that can discharge the pathogen), the way of transmission (the way that the pathogen infects others) and susceptible people (those who have no immunity to this kind of infectious diseases). If one link can be cut off completely, the occurrence and prevalence of this kind of infectious disease can be prevented. The vulnerability of infectious diseases varies. Should make full use of in prevention. In order to better prevent infectious diseases, measures should be taken at other links as well as at the leading ones.
