Coordinated Health


Hookworm is a condition caused by roundworms that affects the small intestine and lungs.

Causes, incidence, and risk factors

The disorder is caused by infestation with the roundworms:

  • Necator americanus
  • Ancylostoma duodenale
  • Ancylostoma ceylanicum
  • Ancylostoma braziliense

The first two roundworms affect humans only. The last two types also occur in animals.

Hookworm disease is common in the moist tropics and subtropics. It affects about 1 billion people worldwide. In developing nations, the disease leads to the death of many children by increasing their risk for infections that their bodies would normally fight off.

There is very little risk of getting the disease in the United States because of advances in sanitation and waste control. The important factor in getting the disease is walking where people who have hookworm have made feces.

The larvae (immature form of the worm) get into the skin. The larvae move to the lungs via the bloodstream and enter the airways. The worms are about 1/2 inch long.

After traveling up the windpipe, the larva are swallowed. After the larvae are swallowed, they infect the small intestine. They develop into adult worms and live there for 1 or more years. Adult worms and larvae are released in the feces.


  • Abdominal discomfort
  • Blood in the stool
  • Bloody sputum
  • Cough
  • Diarrhea
  • Fatigue
  • Fever
  • Gas
  • Itchy rash
  • Loss of appetite
  • Nausea, vomiting
  • Pale skin

Most people have no symptoms once the worms enter the intestines.

Signs and tests

Tests that can help diagnose the infection include:

  • Complete blood count (CBC) with differential
  • Stool ova and parasites exam

This disease may also affect the results of a D-xylose absorption test.


The goals of treatment are to:

  • Cure the infection
  • Treat complications of anemia
  • Improve nutrition

Parasite-killing medications such as albendazole, mebendazole, or pyrantel pamoate are usually prescribed. Ivermectin, used for other worm infections, does not work for hookworm infections.

Symptoms and complications of anemia are treated as they arise. The doctor will likely recommend increasing the amount of protein in your diet.

Expectations (prognosis)

You will have a complete recovery if you get treated before serious complications develop. Treatment gets rid of the infection.


  • Iron deficiency anemia caused by loss of blood
  • Nutritional deficiencies
  • Severe protein loss with fluid buildup in the abdomen (ascites)

Calling your health care provider

Call for an appointment with your health care provider if symptoms of hookworm infection develop.


Developing countries need to improve sanitation measures to prevent infection.