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.
A valley is an area of elongated lowland, typically surrounded by much higher hills or mountains. It is one of many geological features that make up the surface of the Earth, and it is of special interest and importance to humans, thanks to the fact that valleys have a number of uses. This landform is also quite abundant.