show Abstracthide AbstractAscaris species are the largest intestinal worms and responsible for ascariasis, the commonest helminth infection of humans worldwide. Adult Ascaris live in the small intestine, where each female can produce hundreds of thousands of eggs each day. Eggs are passed into the environment where, over about 10 days, they develop into larvae. This takes place in the soil, thus Ascaris (along with hookworms and whipworms) are classified as soil-transmitted helminths. Human infections are common in sub-tropical and tropical areas with poor sanitation and are predominantly due to the species A. lumbricoides. A closely related species A. suum typically infects pigs.