Hookworms

What Are Hookworms?

Hookworms are parasites that live in the small intestine. Like all parasites, they live off other living things, including people.

Most people with hookworms don’t have symptoms of an infection, especially at first. But as the infection gets worse, it can affect your health.

Causes of Hookworm Infection

Hookworms live in warm, moist climates around the world: in the U.S., as well as in the rest of the Americas, Africa, Asia, Australia, the Middle East, and Southern Europe. They’re most likely to infect people living in places with poor sanitation or where human feces are used as fertilizer.

When people have a hookworm infection, their poop will have hookworm eggs in it. If an infected person poops outside or their poop is spread outside later, those hookworm eggs end up in the soil. When the eggs hatch, they release young hookworms, or larvae. If you walk barefoot over this soil, the young worms can enter your body through the skin on your feet and cause an infection. This is the most common way that people get hookworms. It’s also possible to get them from eating contaminated food or drinking contaminated water.

Types of Hookworms

There are a few different species of hookworm. The ones that infect people usually enter the skin as larvae, travel through the body, and attach to the small intestine. That’s where they live and grow into adult worms. One type of hookworm, however, can infect you if you eat or drink something that has its larvae.

Other types of hookworms (including A. braziliense and A. caninum) mostly infect dogs and cats. But they can infect humans, too. They live in your skin and cause problems there.

Symptoms of Hookworm Infections

At first, you might have an itchy rash where the hookworms entered your skin. If the infection is mild, you may not have any other symptoms. But when it’s more severe, it can cause:

• Belly pain
• Diarrhea
• Loss of appetite
• Weight loss
• Feeling tired

Hookworms also can cause blood loss in the intestines, leading to anemia -- when your body doesn’t have enough iron-rich red blood cells. Anemia is the most common sign of a hookworm infection.

Anemia may not cause any symptoms at first, but as it gets worse, you might have:

• Extreme tiredness
• Weakness
• Pale skin
• Chest pain
• Fast heartbeat
• Shortness of breath
• Headache
• Feeling dizzy or lightheaded
• Cold hands and feet

Other symptoms of hookworm infections are:

• Heart problems, which can come along with anemia
• Digestive problems
• Nutritional problems
• Breathing problems

Signs of Hookworm Skin Infection

Some hookworms prefer animal hosts, so they don’t thrive as well in humans. Once these larvae get into human skin, they don’t mature into adults. They also don’t move around in the body much, staying just beneath your skin’s surface. The infection they cause is called cutaneous larva migrans. It’s the top cause of skin infection in people returning to the U.S. from tropical countries.

Symptoms include:

• Skin infection or sores
• Extreme itchiness
• A path of red bumps on your skin
• Rarely, inflamed or infected hair follicles

Hookworm Diagnosis

Your doctor can find out if you have an intestinal hookworm infection by getting a stool sample. A lab can check it for tiny hookworm eggs.

Treatment for Hookworm Infections

Treatment depends on how severe your hookworm infection is.

No treatment. Your body may clear the infection on its own, though it could take a few years.

Anthelmintic medications. These medicines get rid of parasitic worms in the body. Common drugs for intestinal hookworm include albendazole, mebendazole, and pyrantel pamoate. To treat infection by hookworm larvae, you can put the drug thiabendazole on your skin or take a medicine like albendazole or ivermectin by mouth.

Supplements.Iron supplements can treat anemia from the infection. If you have anemia and malnutrition, your treatment will include nutrition support and other supplements, including folate.

Hospitalization. Rarely, hookworms can cause severe anemia and congestive heart failure. Such cases may need treatment in a hospital.

Preventing Hookworm Infection

When you live, travel, or play in an area where the soil may have hookworms, take these precautions:

• Wear shoes outside.
• Avoid skin contact with soil that may be contaminated.
• Avoid eating food that could be contaminated.
• Avoid skin contact with dog poop (especially in parks, where you can’t know if other people’s pets have hookworm).

Some developing countries offer preventive treatment, also known as preventive chemotherapy, to people at high risk for infection, such as pregnant women, children, and people whose jobs could expose them to hookworms.

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