What Is Hookworm? An Infectious Disease Expert Explains What You Need To Know
Just FYI: It's not pleasant.
Listen: Chances are you're not going to get a dreaded hookworm infection (it's been all but eradicated in the US), but it's still something you should have on your radar—especially if you're traveling this summer to other parts of the world where it is prevalent, like Africa, Latin America, and Southeast Asia.
Since the best line of defense against any scary-sounding infection (especially one that has the word "worm" in it) is knowledge, here's what you need to know about hookworm infections, including how they're diagnosed, treated, and what a hookworm even is, anyway.
What is hookworm?
Hookworm is a parasite that, under a microscope, looks like a regular worm you'd see crawling across your driveway. The two main hookworm species are Necator americanus and Ancylostoma duodenale, the CDC explains.
Hookworm essentially lives inside your intestines—and gets there one of two ways: “Hookworm [is] found in the soil. It can be contracted through direct contact of people’s feet,” Camille Sabella, MD, pediatric infectious disease specialist at Cleveland Clinic Children’s, tells Health.
The second way you can develop a hookworm infection is if you ingest soil in which the parasite lives (children playing in a sandbox could come into contact with hookworm this way). Once in your body, hookworm makes its way to your small intestine, where it actually hooks itself on to your intestinal wall to eat red blood cells, via your blood stream and lymphatic tissue, Dr. Sabella says.
But the real gross-out factor happens when hookworm gets to its destination: "Once they get to the small intestine, those adult worms mate in the small intestine. They can lay eggs in the small intestine,” Dr. Sabella says. Then, you pass those eggs in your feces, which is sometimes used in fertilizer—that's how other people can be exposed to it by walking or playing in a field on which fertilizer has been spread. “That’s how you propagate the parasite,” Dr. Sabella says.
What are the symptoms of a hookworm infection?
For the most part, a person with a very light hookworm infection shows very little to no symptoms at all, per the Centers for Disease Control and Prevention (CDC). If a hookworm is picked up through the foot, for example, it can cause a localized rash and itching.
But those with a severe hookworm infection can experience experience abdominal pain, diarrhea, loss of appetite, weight loss, fatigue and anemia, per the CDC. People can also experience a cough, if hookworm winds up in their lungs, Dr. Sabella says.
Luckily, those severe hookworm infections are rare—especially in the US. “Usually it takes a long time and a lot of worms for someone to get symptoms. For iron-deficiency anemia to happen, there has to be a heavy infestation. The infestation has to be going on for a long time. The major symptom of that is fatigue,” Dr. Sabella says. In other words, there have to be lots of hookworms in your small intestine for them to be affecting your body’s iron levels. “To get anemia that is so severe, it probably takes weeks and months and sometimes years.”
So, how is hookworm treated?
If you're having symptoms that suggest a hookworm infection and you live in an area where hookworm is prevalent, Dr. Sabella says your stool would be tested for hookworm eggs. The good news? “Usually it’s treatable,” Dr. Sabella says. Antiparasitic tablets can be used to treat a hookworm infection.
While treating a hookworm infection with an antiparasitic can make it go away for good, long-term damage from a hookworm infection is a possibility if the infection is severe enough. “Learning disabilities [and] neurologic problems [can occur] depending on how long somebody’s been iron-deficient,” Dr. Sabella says.
But remember: Hookworm is extremely rare in the US. While the CDC says that up to 740 million people around the world have been infected with hookworm, "improvements in living conditions have greatly reduced hookworm infections" in the US, says Dr. Sabella. To leave you on an even more reassuring note: “I’ve been practicing 25 years, and I can’t say I’ve seen a case of hookworm,” says Dr. Sabella—so feel free to walk around barefoot, if you so choose (within reason, of course).