Children are most commonly infected. Estimated prevalence rates among children in various world regions are 4â28%. Ascariasis: Ascaris, or roundworm, infection is the common helminthic infection in humans, with an estimated worldwide prevalence of 1 billion. The causative organism, A lumbricoides, is cosmopolitan in distribution, being most abundant in tropical countries.
Definition of hollow. 1  1 : an unfilled space : cavity, hole in the hollow of a tree. 2  2 : a depressed or low part of a surface; especially : a small valley or basin.
Definition of valley. plural. valleys. 1a : an elongate depression of the earth's surface usually between ranges of hills or mountainsb : an area drained by a river and its tributaries. 2 : a low point or condition. 3a : hollow, depressionb : the place of meeting of two slopes of a roof that form on the plan a reentrant angle.