Symbiosis and the way in which the symbiotic relationship works may seem confusing to understand, but it is actually quite simple. The term Symbiosis refers to any close and long term interaction between different biological species where at least one member of the pair benefits from the relationship in some way. Not all of these relationships may be classified as parasitic. Some may be commensal, which means the symbiotic organism is not directly benefiting from the relationship and remains relatively unaffected; while others may be mutual, meaning one symbiotic organism directly benefits from the relationship, while the other may benefit slightly. Parasitic relationships only occur when one organism is left injured from the interaction.
It is commonly misunderstood that symbiotic parasites harm the body. This is untrue, these interactions and the presence of symbiotic parasites in the body are actually necessary and helpful to humans. Parasitic relationships are actually the ones that humans should be wary of. Parasitic symbioses may appear in may forms. Common forms of these parasitic relationships include endoparasites that live within the body of the host; ectoparasites that live on the body’s surface; nectrophic parasites that eventually kill the host; or biotrophic parasites that cannot survive unless their host does. If a human has a tick or flea present within the body, for example, this would be a parasitic relationship between the human host and the nectrophic parasite.
Therefore, Symbiosis is a broad term encompassing any and all interactions between two separate biological species or organisms. There are many types of relationships and interactions between organisms, and it is important to remember that most of these relationships, contrary to popular belief, are not harmful. It is only the parasitic subtype of the symbiotic interaction that is dangerous to humans. Examples of these types of parasitic infections in humans may include some worm infections such as pinworms, hookworms, roundworms, tapeworms, and liver fluke; or protozoa infections such as Giardia lamblia, Entamoeba histolytica, Cryptosporidium, and Toxoplasma gondii.
These infections might be contracted from a number of things including, but not limited to being bitten by an insect, handling animal feces, going barefoot in the outdoors, handling or eating raw or undercooked pork, beef or fish, eating contaminated and uncooked fruits or vegetables, having a meal prepared without the proper sanitary precautions or by an infected food handler, drinking contaminated water, having any physical or sexual contact with an infected person or inhaling parasitic eggs or cysts that may be found in dust. Avoiding these activities and practicing good hygiene can significantly reduce one’s risk of contracting a parasitic infection. However, one must learn to differentiate between the different types of the symbiotic relationship in order to stay informed and healthy.