Helminthiasis is infestation with one or more intestinal parasitic worms (roundworms (Ascaris lumbricoides), whipworms (Trichuris trichiura), or hookworms (Necator americanus and Ancylostoma duodenale)).
Infected people excrete helminth eggs in their faeces, which then contaminate the soil in areas with inadequate sanitation. Other people can then be infected by ingesting eggs or larvae in contaminated food, or through penetration of the skin by infective larvae in the soil (hookworms).
Infestation can cause morbidity, and sometimes death, by compromising nutritional status, affecting cognitive processes, inducing tissue reactions, such as granuloma, and provoking intestinal obstruction or rectal prolapse. Control of helminthiasis is based on drug treatment, improved sanitation and health education.