Hookworms are parasites. This means they live off other living things. Hookworms affect your lungs and small intestine. Humans contract hookworms through roundworm eggs and larvae found in dirt contaminated by feces.
According to the Centers for Disease Control and Prevention (CDC), hookworm infections occur in an estimated 576 to 740 million people worldwide (CDC, 2010). It mainly affects people in developing nations in the tropics and subtropics due to poor sanitation. These infections rarely occur in the United States.
Parasitic roundworms, called hookworms, cause these infections. The Necator americanus hookworm is the most common cause of this condition in the United States. The other type that causes infections in humans is Ancylostoma duodenale. There are two other types of hookworms, but they mainly affect animals.
The eggs of these hookworms end up on the ground after passing through human feces. They hatch into larvae, which stay in the soil until they have a chance to break through human skin.
You can become infected with hookworms by coming into contact with soil that contains their eggs or larvae. The larvae enter your skin, travel through your bloodstream, and enter your lungs. They also travel to your windpipe and are carried to your small intestine when you swallow. Fully grown, they can live in your small intestine for a year or more before passing through your feces.
People who live in warm climates in areas with poor hygiene and sanitation are more at risk of suffering from hookworm infections.
Hookworm infections can occur in pets, especially puppies and kittens. If your pet has an infection, you can get it indirectly. You won’t get it from petting your dog or cat. The eggs are passed in your pet’s stool and hatch into larvae. The eggs and larvae are found in the dirt where your pet leaves stool. You can get a hookworm infection by touching contaminated dirt with your bare hands or feet. You can also get it by accidentally eating contaminated soil.
To reduce your risk, make sure your pets are vaccinated and dewormed by your veterinarian. Also, avoid walking barefoot in areas where pets leave feces. This is especially important when you might come in contact with animal feces from pets whose health conditions are unknown, such as at a park.
If you’re otherwise healthy and eat foods with plenty of iron, you might not have any symptoms from the infection.
If you do experience symptoms, they generally start with itchiness and a small rash caused by an allergic reaction as the larvae enters your skin. This is generally followed by diarrhea as the hookworms grow in your intestine. Other symptoms include:
- abdominal pain
- colic (cramping and excessive crying in infants)
- intestinal cramps
- blood in your stool
- appetite loss
- itchy rash
If you have a hookworm infection that lasts a long time, you could become anemic. Anemia is characterized by a low red blood cell count, which can lead to heart failure in severe cases. Anemia results from hookworms feeding on your blood. You’re more at risk of having severe anemia if you also don’t eat well, are pregnant, or have malaria.
Other complications that can develop from these infections include nutritional deficiencies and a condition known as ascites. This condition is caused by serious protein loss and results in fluid buildup in your abdomen.
Children who have frequent hookworm infections can experience slow growth and mental development from losing a lot of iron and protein.
Treatment for hookworm infections aims to get rid of the parasites, improve nutrition, and treat complications from anemia. Your doctor will prescribe medications that destroy parasites, such as albendazole and mebendazole. These medications are generally taken for one to three days to treat the infection.
Your doctor might also have you take an iron supplement if you have anemia. Your doctor will also help you recover from any nutritional deficiencies you have. If you have ascites, you will add additional protein to your diet.
You can lower your risk of becoming infected with hookworms by wearing shoes when you walk outdoors, especially in areas that might have feces in the soil.
In areas where hookworm infections are common, improving sanitation can reduce the number of infections. This includes using better sewage disposal systems and reducing human defecation that occurs outdoors.
Some developing nations practice preventive treatment. This involves treating groups of people who are at a higher risk of having infections. These include:
- young children
- women of childbearing age
- pregnant women
- women who are lactating
- adults who work in occupations that put them at risk for heavy infections