Hook Worm Infection

Hookworm infections are caused by four different roundworms. Two of these roundworms occur only in humans, one can affect humans and other animals and one occurs only in other animals according to the Centers for Disease Prevention and Control (CDC).

Hookworm infection is most prevalent in the tropics and subtropics. The risk of contracting hookworm infection is low in the U.S. because of sanitation and waste practices.

Life Cycle of the Hookworm

• Hookworm larvae can penetrate the skin.

  The hookworm life cycle begins and ends in the small intestine. Hookworm eggs populate the soil when infected people defecate on the ground or when human feces is used to fertilize crops. Warm, moist and shady conditions trigger the eggs to hatch into larvae.

  The larvae are either accidentally ingested or penetrate bare feet. They enter the lungs through the bloodstream and travel up the windpipe and are swallowed. They develop into half-inch worms in the intestines, attach themselves to intestinal walls and feed on blood.

How Humans Are Infected

• Human waste or "night soil" is sometimes used as fertilizer.

  Direct contact with larvae in soil can result in hookworm infection. Ingesting such soil or walking barefoot allows larvae to penetrate the body. Eggs themselves are not infective.

  Humans can get some hookworm infections from dogs and cats that pass the eggs and larvae to the soil. Puppies and kittens are more likely to have hookworm infections, and children are more likely to play in areas where they could pick up a hookworm infection.

  Areas that are contaminated with human feces pose the most risk of hookworm infections in humans. It is through soil, not direct contact with infected people, that the infection is spread.

Symptoms

• Hookworm infections can retard growth and development.

  The National Institutes of Health (NIH) warns that most people don't experience symptoms of hookworm infection once it has entered the intestines. In early stages of hookworm infection, the traveling of larvae through the skin can cause itchy and painful infections. If hookworm eggs are ingested; the hatching of larvae in the intestines can cause abdominal pain, bleeding and inflammation. Itching and a rash can occur at the site of skin penetration. Possible symptoms include diarrhea, fatigue, fever, and gas, loss of appetite and nausea and vomiting.

Health Problems

• Hookworm is more common where modern sanitation is lacking.

  Heavy infestations can cause anemia and weight loss and can stunt growth and mental development, according to the CDC. The blood and protein loss can cause breathing difficulties and congestive heart failure. Nutritional deficiencies and fluid build-up in the abdomen are common with heavy infestations of the hookworm and are especially threatening to children and pregnant women.

Prevention

• Having dogs and cats de-wormed lowers the spread of hookworm infections.

  You can reduce your risk of contracting a hookworm infection by avoiding contact with sand and soil likely to be infested with hookworm. Don't walk barefoot in such areas and wear gloves when working with soil. You should also have pets de-wormed.