Indirect contact includes airborne transmission, object contamination, food and water contamination and human-to-animal exchange. Examples of direct contact include human touch and spray or exchange of bodily fluids.
Direct and indirect contact refer to the transmission of infectious diseases. Not all diseases are contagious by both direct and indirect contact. Some can only be contracted through direct contact. The exchange of bodily fluids, such as saliva or blood, is considered direct contact because an infected element of one person's body is directly coming into contact with another. This is also why spray, such as sneezing, is considered direct contact. Even though a person who sneezes does not directly touch another, it is still possible for the exchange of bodily fluids to take place through spray.
Indirect contact refers to a person who contracts a disease without coming into direct contact with the infected person or the infected person's bodily fluids. Some diseases are actually airborne diseases, meaning a person can infect those around him just by being in the same space. It's also possible to catch a disease that is transmitted indirectly by touching an object that an infected person has touched. Some bacteria do not immediately die and actually multiply on surfaces, particularly surfaces that are unclean. Being bitten by an insect or animal that has been infected can cause someone to contract a disease, as can drinking or eating contaminated food.