Saliva exchange is a term used to describe any situation where a person’s saliva is transferred to another person. Sometimes this can be direct, through actions like kissing, but it can also be indirect, with saliva passing from a person to an object and then to another person. An exchange of saliva is often a cause of infection transmission because saliva can carry viruses and bacteria.
Generally speaking, there are quite a few different ways that a saliva exchange can happen. The most common example that people generally think of is the kiss, but there are also others. For example, any time people eat after each other, or if utensils pass from one person to another, a small possibility of saliva exchange is generally present. Indirect saliva exchange also happens in some cases among children who may have a strong tendency to chew on their toys. People who carry this habit into adulthood and chew on their pens or pencils may also be inadvertently spreading their saliva to others.
The human mouth may sometimes have a fair amount of bacteria present. This is partly because of moisture and partly because food items may occasionally get stuck in the teeth. Brushing and oral hygiene can potentially help in that regard, but it isn’t generally considered foolproof. When saliva exchange occurs, some of these bacteria may move from one person to another, and in some cases, this can lead to serious problems.
Some of the microorganisms that live in the mouth can lead to major bacterial diseases, and there are also some viral illnesses that can be passed through saliva. Generally speaking, most things that can be passed through mucus exchange, such as colds or influenza, can also be passed through saliva. So in general, kissing or drinking after people who are sick may be just as dangerous as being sneezed on, and sometimes even more dangerous.
When it comes to infectious diseases that are passed through salivary exchange, the most classic example is probably mononucleosis, which has sometimes been called the kissing sickness because of this common method of transmission. Another fairly common and sometimes serious illness that has been known to frequently pass through salivary exchange is strep throat. Overall, doctors generally suggest that people take a few precautions to avoid salivary exchange when a known contagion is present, generally including an avoidance of things like kissing and eating with the same utensils.