small areas of United States, the Caribbean islands, and South America. This hookworm is well known in mines because of the consistency in temperature and humidity that provides an ideal habitat for egg and juvenile development. An estimated 1 billion people are infected with hookworms. Transmission of A. duodenale is by contact of skin with soil contaminated with larvae. The way it enters the human body was understood in the 1880s, after an epidemic of ancylostomiasis among miners working in the hot and humid Gotthard Tunnel (Switzerland). Infection A light hookworm infection causes abdominal pain, loss of appetite, and geophagy. Heavy infection causes severe protein deficiency or iron-deficiency anemia. Protein deficiency may lead to dry skin, edema, and abdominal distension from edema (potbelly), while iron-deficiency anemia might result in mental dullness and heart failure. In pregnant women, this parasite is able to infect the fetus and can cause complications such as low birth weight, maternal anemia, and infant mortality. The eggs of A. duodenale and Necator americanus cannot be distinguished. Larvae cannot be found in stool specimens unless they are left at ambient temperature for a day or more. Education, improved sanitation, and controlled disposal of human feces are important. Wearing shoes in endemic areas can reduce the prevalence of infection, as well. A. duodenale can be treated with albendazole, mebendazole, and benzimidazoles. Pyrantel pamoate is an alternative. In severe cases of anemia, blood transfusion may be necessary. References Further reading External links Ancylostoma duodenale image library at DPD Parasitic diseases Parasitic nematodes of humans Parasites of cats Parasites of dogs Ancylostomatidae Nematodes described in 1843