Screwworm myiasis causes staining fur around infested wounds with malodorous blooding exudates. Pathological effects include mechanical irritation because of larval feeding until dead of hosts under successive infestations. In natural conditions, population densities of screwworm fly are low. Its distribution follows running waters, potential hosts proximity and vegetation density. Warm and moist climate increases of screwworm populations. Among domestic animals, cattle are mostly affected by screwworm myiasis. Risk factors in animals are related to management practices. In humans, the children and the elderly, homeless and dirty, are more vulnerable. Technical aspects for analysis in planning ecological and epidemiological studies in Colombia are pointed out.