What is hookworm disease?
Hookworm disease is a parasitic disease caused by the entry of larvae (immature form) of the hookworm, most commonly, Necator americanus, into a human host. People usually get hookworm disease by walking barefoot in soil that is contaminated with the feces of an infected person. Hookworm larvae enter through the skin, typically on the foot, and travel up through the bloodstream into the lungs. From the lungs, they are coughed up into the mouth, where they are swallowed and travel through the gastrointestinal tract to infest the small intestine.
Hookworm disease affects approximately 740 million people worldwide, mostly in tropical and subtropical areas. Hookworm is rare in regions that receive less than 40 inches of annual rainfall. It was once a problem in the southern United States but has largely been contained as a result of improved hygiene. (Source
Hookworm disease can produce an itchy rash, often called ground itch, at the site of initial skin infection. When the hookworm larvae are present in the lungs, coughing with or without bloody sputum may result. When present in the intestines, hookworm infection usually does not produce any recognizable symptoms. However, some people may experience diarrhea, abdominal pain, intestinal cramps, and nausea. Chronic or persistent hookworm disease can cause anemia (low red blood count) due to blood loss, especially in people with poor health or in pregnant women.
Seek prompt medical care if you experience nausea and diarrhea, especially if these symptoms persist or worsen over time. Vomiting and diarrhea can cause dehydration and require treatment with intravenous fluids. You should also seek prompt medical care if you experience fatigue, pale skin, shortness of breath, and chest pains, which may be symptoms of anemia.
What are the symptoms of hookworm disease?
In most cases, you will not experience symptoms if you have a hookworm infestation in the intestines. However, as the hookworm larvae mature in the intestines, gastrointestinal symptoms, such as diarrhea, nausea and vomiting, may sometimes occur. Some people experience itching, swelling or redness of the skin where the larvae entered the body. Coughing and respiratory symptoms may result from the presence of hookworm larvae in the lungs.
Common gastrointestinal symptoms of hookworm disease
Hookworm disease may cause gastrointestinal symptoms including:
- Abdominal pain or cramping (often worse after eating)
- Bloody stool (the blood may be red, black, or tarry in texture)
- Diarrhea
- Flatulence
- Gas
- Loss of appetite
- Nausea with or without vomiting
Other symptoms of hookworm disease
Hookworm disease can sometimes cause symptoms in other body systems. Examples include:
Symptoms that might indicate a serious condition
In some cases, hookworm disease can be a serious condition that should be immediately evaluated in an emergency setting. Seek immediate medical care (call 911) if you, or someone you are with, have any of these serious symptoms including:
Nausea, vomiting and diarrhea, which can lead to dehydration, potentially requiring intravenous fluids
Symptoms of anemia such as shortness of breath, lightheadedness, and fatigue, which can be due to blood loss from the hookworm attaching itself to the intestine; pregnant women, the elderly, and those in poor health are susceptible
What causes hookworm disease?
Hookworm disease is caused by parasitic hookworms in the human body, usually picked up from contact with contaminated soil. Necator americanus is the type of hookworm that most commonly causes infestation in the United States, but other types of hookworm may also cause disease in humans and animals. Hookworm infestation is most common in moist, subtropical areas. Hookworm eggs are deposited into the soil through contaminated human feces. After hookworm larvae hatch from these eggs and come into contact with a human host, they penetrate the skin and enter the body.
What are the risk factors for hookworm disease?
A number of factors increase the risk of developing hookworm disease. Not all people with risk factors will get hookworm disease. Risk factors for hookworm disease include:
Contact with contaminated soil or sand, especially when walking barefoot
Residence or travel in an area with poor sanitation, where human fecal matter may contaminate the soil
How is hookworm disease treated?
Treatment for hookworm disease begins with seeking medical care from your health care provider. To determine if you have hookworms, your health care provider will ask you to provide stool samples for laboratory testing.
Anthelmintics, which are drugs that eliminate parasitic worms, are the standard treatment for hookworm disease. It is important to follow your treatment plan precisely and to take all of your medication as instructed to avoid reinfection or recurrence.
Anthelmintic medications for treatment of hookworm
Anthelmintic medications that are effective in the treatment of hookworm disease include:
- Albendazole (Albenza)
- Mebendazole (Vermox)
If you have anemia related to hookworm disease, your doctor may also prescribe iron supplements and recommend the inclusion of more protein in your diet.
What are the potential complications of hookworm disease?
Treatment of hookworm disease usually results in full recovery; complications are rare unless the infection is left untreated. However, if anemia occurs, it can be severe in people who have chronic disease or poor nutrition, are pregnant, or are in poor health.
Complications of hookworm include:
- Anemia (low red blood cell count)
- Ascites (accumulation of fluid in the abdomen)
- Nutritional deficiencies
