The noun invasion has its origins in the 12^th century Latin word invadere: to walk, to go into, to fall upon. In the 15^th century we adopted the Old French term invasion, which is steeped in negative concepts like attack and assault. This definition, ubiquitous across healthcare, remains in use today. It stands to reason then, that anything that invades the body must be bad and must be controlled.

As the dominion of the human body is continuously under attack from invasions (some necessary, such as medicines, others unwanted, such as bullets and bacteria) invaders are acceptable if they are beneficent and as long as they remain confined inside the body they are intended to help (as in virotherapy and introduced invasions, such as prostheses and prescription medicines, where an attenuated virus enters our body and is unable to leave to harm anyone else).

In expending biological knowledge and modern medical advances we cloud the distinctions between “good” and “bad” invaders and this makes good and bad invaders difficult to differentiate and therefore control. For example, viruses were thought to be bad because they caused cold sores but now they are considered good because they can cure cancer.

When invaders and invasions have the potential to be controlled externally they foray into a two-way street

When invaders and invasions have the potential to be controlled externally they foray into a two-way street, which also might be good but could be bad, we don’t yet know. In recent years newer incursions, such as nanoparticles, have broken through this frontier to allow external governance by transmitting data from the body to the outside world.

Take the role of nanoparticles in diabetes. These invaders can monitor (continuous nanaoparticle monitoring of blood glucose can be relayed to an outside monitor) and treat (ensuing remote control of insulin pumps can also be effected by nanoparticles) without the conscious recognition of the diabetic patient.

However, this two-way traffic exposes another invasion: that of our privacy (or, if we adopt the Latin definition: it allows a third-party to “walk into” our personal health data) and this raises the question of whether we need to collectively control the management of information for the protection of individuals, as occurs in more formal settings such as hospitals and clinics. Or should we be making our own decisions about data collected on us, as we do when we give Facebook permission to access and send texts and make calls on our devices or allow GPS software to locate our position?