Ascaris

Ascaris
Adult female
Life cycle inside and outside of the human body of one fairly well described helminth: Ascaris lumbricoides
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Nematoda
Class: Chromadorea
Order: Ascaridida
Family: Ascarididae
Genus: Ascaris
Linnaeus, 1758
Species

Ascaris is a nematode genus of parasitic worms known as the "small intestinal roundworms". One species, Ascaris lumbricoides, affects humans and causes the disease ascariasis. Another species, Ascaris suum, typically infects pigs. Other ascarid genera infect other animals, such as Parascaris equorum, the equine roundworm, and Toxocara and Toxascaris, which infect dogs and cats.

Their eggs are deposited in feces and soil. Plants with the eggs on them infect any organism that consumes them. A. lumbricoides is the largest intestinal roundworm and is the most common helminth infection of humans worldwide. Infestation can cause morbidity by compromising nutritional status, affecting cognitive processes, inducing tissue reactions such as granuloma to larval stages, and by causing intestinal obstruction, which can be fatal.