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.
An elongated lowland between ranges of mountains, hills, or other uplands, often having a river or stream running along the bottom. 2. An extensive area of land drained or irrigated by a river system. 3. A depression or hollow resembling or suggesting a valley, as the point at which the two slopes of a roof meet.