The description on the youtube site says something about 'jiggers', and then:
M^^EDICAL CONDITION: The condition depicted is known as "Tungiasis". It is an infestation of the skin by a burrowing flea. These fleas tend to infest those who have inadequate living conditions and sanitation. The flea lives both outside around warm-blooded mammals and inside poorly constructed homes. It inhabits dust on floors, cracks in walls and bedding. Shoes protect to some degree but are often not affordable or adequate.