How do people get noncontagious viral infections or disease if they e noncontagious?
There are 2 main types of disease – contagious (aka infectious or transmissible) and non-contagious. Contagious diseases are able to pass from one person (or animal) to another. Noncontagious conditions cannot be spread from person to person – ie you cannot “catch” a non-contagious disease. Non-contagious diseases may be inherited, or caused by things in the environment such as radiation exposure, chemicals, lifestyle factors, etc (eg skin cancer is caused by sun exposure, lung cancer is caused by smoking). Many noncontagious diseases have multiple causes that interact together – ie they may be partly inherited and partly due to the environment. There are 4 types of contagions – viruses, parasites, fungi and bacteria. Viral infections are always contagious. However the ways in which they spread may differ from virus to virus. Eg some viruses spread through the air, others need direct contact to spread. Contagious and non-contagious diseases can be related. For example, the virus Human
