|  | Conditions Treatments | Medical Conditions

Hook Worms in Humans

Hookworms are the second most common type of parasitic nematode in humans, according to the Centers for Disease Control and Prevention. Various species of hookworms that infect humans are found around the world with most cases of infection occurring in warm and moist climates.

The CDC reports that in 2002, nearly 1.3 billion people around the world were infected with hookworms.

  1. Species

    • Hookworms infecting humans include the species Ancylostoma duodenale and Nectar americanus. There are also species of hookworms that affect pets that can infect people as well as certain species of hookworms that can penetrate the human skin, but go no further in causing illness.

    Transmission

    • Hookworm eggs are found in the soil where they hatch into larvae that have the ability to penetrate human skin. The infection takes place in humans, most often, by walking barefoot on infected soil. However, infection can also take place by ingestion of the larvae when hands or food are contaminated with infected soil.

    Zoonotic

    • Hookworms are common in dogs and cats, especially puppies and kittens. The nematode can be transmitted to humans, especially children, through ingestion of contaminated soil or penetration of the skin. To prevent zoonotic infection of hookworms, pets should be de-wormed on a regular basis.

    Life cycle

    • The life cycle of the hookworm begins in the intestines where the adult female hookworm produces thousands of eggs that are passed from the body in the stool. In the soil, the eggs hatch into larvae and the larvae penetrate the skin. From there the larvae travel to the lungs, go into the respiratory tract and then to the mouth. They are swallowed and journey to the small intestines. In the small intestines, the larvae develop into worms that are about a half-inch long. They attach themselves to the intestinal wall and feed on the host's blood.

    Symptoms

    • Common symptoms of a hookworm infection are diarrhea and abdominal pain. There may be itching and a rash at the site where the hookworm entered through the skin. Symptoms of a hookworm infection can also include iron deficiency anemia, caused by loss of blood where the adult worms have attached to the intestine. Cardiac, pulmonary gastrointestinal, nutritional and metabolic symptoms may also be present where there is severe infection or in infants, the elderly or those with compromised immune systems.

    Diagnosis

    • To diagnose a hookworm infection, microscopic identification of the eggs in a stool sample is necessary. This method of diagnosis, however, does not determine which species of hookworms is infecting the patient.

    Treatment

    • Treatment of a hookworm infection is usually with the medication albendazole, mebendazole or pyrantel pamoate.

Medical Conditions - Related Articles