Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:
Adult hookworms (Ancylostoma
duodenale and Necator americanus)
parasitize the upper part of the human small intestine, whereas
Ascaris lumbricoides parasitize the entire
small intestine and adult
Trichuris trichiura live in the large intestine, especially the caecum.
The parasites can live for several years in the human
gastrointestinal tract. After mating, each adult female produces thousands of
eggs per day which leave the body in the feces.
Contact with soil contaminated with eggs or larvae of nematode
parasites is a common form of transmission that results in human infection. The
nematodes can live for years as adults in the human intestinal tract. Soil
becomes contaminated by fecal material of infected humans and other animal
More than a billion people are infected with at least one species.
The most important nematode infections of the human gastrointestinal tract are
the intestinal roundworm (Ascaris lumbricoides),
whipworm (Trichuris trichiura), and
hookworm (Necator americanus or Ancylostoma
It is common for a single individual, especially a child living in a less
developed country, to be chronically infected with all three of the nematode
parasites, which results in malnutrition, stunted growth stunting, retarded
intellectual development, and cognitive and educational deficiencies.
Bethony, J., Brooker, S., Albonico, M., Geiger, S.M., Loukas, A., Diemert, D.,
Hotez, P.J. 2006.
Soil-transmitted helminth infections: ascariasis, trichuriasis, and hookworm.
The Lancet 9521:1521-1532.
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