Ascaris

Ascaris is a genus of parasitic nematode worms known as the "large intestinal roundworms". One species, A. suum, typically infects pigs, while another, A. lumbricoides, affects humans, typically people living in sub-tropical and tropical areas with poor sanitation. A. lumbricoides is the largest intestinal roundworm and is the most common helminth infection of humans worldwide, a disease known as ascariasis. 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.