What is Hookworm Infection

Hookworm infection is caused by parasitic roundworms that can live in the intestines or lungs. Hookworm infection is not common in the United States, but it is very common in developing parts of the world, especially in areas that have poor sanitation.

Young hookworms (larvae) can enter the skin and travel to the lungs through the bloodstream. The hookworms can move up the windpipe (trachea) and down into the digestive tract. Adult hookworms can live for a year or more inside the small intestine. If an infection is not diagnosed and is not treated, it can eventually lead to blood loss from the intestines and cause a low level of iron in the blood (iron-deficiency anemia).

What are the causes?

Hookworm infection is mainly caused by worms of two species (Ancylostoma duodenale and Necator americanus). An infected person passes hookworm eggs through stool (feces). Feces can get into the soil in areas where there is poor sanitation or where human feces are used as fertilizer. Hookworm eggs may develop into larvae and stay in the soil. Then, the larvae can pass into another person’s skin after that person has contact with soil that contains the larvae (contaminated soil).

What increases the risk?

You may be at risk for a hookworm infection if:

• You live or travel in tropical or subtropical areas where these infections are common. These are often areas with poor sanitation. These areas include parts of:
  • Asia.
  • Africa.
  • Latin America.
• You walk barefoot in soil that may be contaminated with hookworm larvae.

What are the signs or symptoms?

The first sign of infection is usually a very itchy rash in the spot on the body where the larvae entered the skin. This is usually on the hands or feet. As the worms pass through the body, other signs and symptoms may develop, including:

• Coughing, wheezing, sore throat, or fever as the worms infect the lungs. This may happen about a week after infection and may last for a month or longer.
• Symptoms that involve the digestive system. These may develop about 30–45 days after infection ang may include:
  • Pain in the abdomen.
  • Gas.
  • Nausea.
  • Loss of appetite.

If worms have been living in the small intestine, you may develop:

• Diarrhea.
• Blood loss after having a bowel movement.

If you develop iron deficiency anemia, the symptoms can include:

• Fatigue or weakness.
• Headache or irritability.
• Pale skin, lips, and nail beds.
• Poor appetite.
• Dizziness, shortness of breath, or rapid breathing.
• Cold hands and feet.
• Fast or irregular heartbeat.

How is this diagnosed?

This condition may be diagnosed based on your symptoms and your travel history. A physical exam and tests will be done to confirm the diagnosis. Tests may include:

• Giving a stool sample to be examined under a microscope for hookworm eggs.
• Having a blood test called a complete blood count (CBC), or other tests that check for iron deficiency anemia or problems with poor nutrition.

How is this treated?

A hookworm infection may be treated with medicines that kill parasitic worms (anthelmintic medicines). Most infections get better after 1–3 days of treatment. Iron deficiency anemia may be treated with iron supplements and an iron-rich diet.

Follow these instructions at home:

• Take over-the-counter and prescription medicines only as told by your health care provider.
• If directed, eat foods that contain a lot of iron, such as:
  • Liver and organ meats.
  • Low-fat (lean) beef, pork, lamb, shellfish, sardines, and anchovies.
  • Breads, cereals, pasta, and grains that are fortified with iron.
  • Eggs.
  • Dried fruit.
  • Dark green leafy vegetables.
  • Peas, lima beans, pinto beans, and black-eyed peas.
• To help your body use the iron from iron-rich foods, eat those foods at the same time as fresh fruits and vegetables that are high in vitamin C. Foods that are high in vitamin C include oranges, peppers, tomatoes, and mango.
• Drink enough fluid to keep your urine clear or pale yellow.
• Keep all follow-up visits as told by your health care provider. This is important.

How is this prevented?

To prevent a hookworm infection:

• Do not wear open-toed shoes and do not walk barefoot.
• Do not touch soil in areas where:
  • Sanitation is poor.
  • Human feces are used for fertilizer.
  • Hookworm infections are common.
• Wash your hands frequently with soap and water. If soap and water are not available, use hand sanitizer.

Contact a health care provider if:

• You have symptoms that do not get better after treatment.
• You develop new symptoms of hookworm infection.