Ascaris lumbricoides and Trichuris trichiura

The eggs of these roundworms are "sticky" and may be transmitted to the mouth by hands, other body parts, fomites (inanimate objects), or foods.

Ascariasis and trichuriasis are the names of these infections. Ascariasis is also known commonly as the "large roundworm" infection and trichuriasis as "whip worm" infection.

Infection with one or a few Ascaris sp. may be asymptomatic unless noticed when passed in the feces, or, on occasion, crawling up into the throat and trying to exit through the mouth or nose. Infection from numerous worms may result in a pneumonitis during the migratory phase when larvae that have hatched from the small intestine penetrate into tissues and travel by way of lymph and blood to the lungs. In the lungs, the larvae break out and ascend into the throat and descend back down the small intestine where they grow.

Molting (ecdysis) occurs at various points along this path and, typically for roundworms, the male and female adults in the intestine are 5th-stage nematodes. Vague digestive tract discomfort accompanies the intestinal infection. Some worms wander and may locate in diverse sites throughout the body causing complications.

Treatment with anthelmintics is likely to cause the intestinal adult worms to wander.

Trichuris sp. larvae do not migrate after hatching but grow and mature in the intestine. Symptoms range from inapparent through vague digestive tract distress to emaciation with dry skin and diarrhea (usually mucoid). Toxic or allergic symptoms may also occur.

Both infections are diagnosed by finding the typical eggs in the patient's feces; on occasion the larval or adult worms are found in the feces or, especially for Ascaris sp., in the throat, mouth, or nose.

Worms are found in poorly treated sewage-fertilizer. Humans are infected when produce is consumed raw. Infected food handlers may contaminate a wide variety of foods.

Both infections may self-cure after the larvae have matured into adults or may require antihelmintic treatment. In severe cases, surgical removal may be necessary. Allergic symptoms (especially but not exclusively of the asthmatic sort) are common in long-lasting infections or upon reinfection in Ascariasis.