Plantar fasciitis or inflammation of the plantar fascia comes about when the ligament suffers very small tears where it inserts into the heel bone, or along its length. With poor foot mechanics, too...
Not being a 'disease' so much as a condition, and not one that is contageous, there is not much point in trying to find out. And it can come and go. I had it for a couple of years, no longer have...