Saturday, October 18, 2014

GPS Evidence: Contact Tracing, refreshed recollection and GPS evidence

      In any serious health care crisis, (communicable disease outbreak,food poisoning, or exposure to chemical or biological hazards), health care agents will likely need to track contacts that a patient has had. At the time I'm writing this blog, Ebola contract tracing is extremely important. While health care contract trackers primarily rely on a patient's memory, the patient, by virtue of their symptoms, will not have as good a memory as they might without whatever illness or impairment that bought them to medical attention. Furthermore, none of us have a good memory for details, especially when the history desired can go back days at best, and weeks at most. A history of contacts can be jumbled against the background of mundane repetitive actions and activities we all engage in to survive, but engage in on autopilot.
            GPS evidence, likely stored either on a cell phone, or with a patient's cell phone provider, can provide a context that will allow a patient to give a better history of events. GPS evidence tracks will give both a locational context and an accurate time line that will help a patient recall details- and these details will lead to potentially missed contacts. For instance, GPS evidence that the patient went to a certain store on a particular evening might jog the memory that the trip was made to buy a pizza, which the patient prepared for a birthday the following day and served to several people, who the patient can then list. With a cell phone GPS time line of when and where, a patient can provide the why, which will probably trigger information about the who.
          GPS evidence can also rule out spurious recollections – by accounting for the patients time, GPS evidence can rule out recollections the patient might have of contacts prior to exposure to the health hazard or communicable disease. Of course, avoiding tracking down people the patient hasn't had contact with clearly saves health care agent resources. Because each actual contact might lead to another string of contacts to investigate, avoiding mistaken investigations might make the difference between containing an outbreak and having sufficient manpower to fully contain an outbreak.
         Where many contacts have GPS enabled cell phones, GPS evidence from the phones themselves can either confirm or refute actual contact between the diagnosed patient and the alleged contact. Agents can compare the patient's GPS track history with the track history of the alleged contact, determine if the two GPS tracks meet, and when they met. If they never met at all (and both the patient and the potential contact agree they both carry their phones at all times), then contact never occurred, and that branch of the investigation can be closed, with confidence.
          Why would the patient allow disclosure of their cell phone GPS evidence history? Because their possible contacts, like relatives, co-workers, and acquaintances, are both innocent and important to the patient. Potential contacts should co-operate for no less reason than to either rule themselves out (and avoid unnecessary treatment and further investigation) or to confirm they are at risk, so they can watch for potential signs or symptoms, so they can go into treatment as soon as possible.
         What of the actual confirmed contact that doesn't have symptoms, but also doesn't have a GPS enabled phone? Health care workers should give such a person a GPS enabled phone, both 1) for quick contact and further checkups; and 2) to easily construct a GPS time and movement history to help that contact develop a chronological and geographically based contact list as soon as symptoms develop.

           Finally, heath care agents themselves should carry GPS tracking devices in case they become infected or exposed to the communicable disease or health hazard. Their own tracks will easily reconstruct positively who they had contact with.