When I worked in public health, we had a guy who was an MD in India or Pakistan but didn't have the interest or will to get his Canadian license. He was a Manager at the health unit for a number of years before moving on. If you like public health, there is definitely work out there without climbing the mountain of residency and so on: health promoter; public health inspector; research associate (for example, with Public Health Ontario); Ministry analyst; and so on.