Hook Worms

A hook worm grows in the small intestine of humans, cats, and dogs, growing and putting its host at risk for infection. Why would someone volunteer to be infected with hook worms? Patients undergo helminthic therapy to cure or control certain diseases, like Crohn’s.

Helminthic Therapy

Helminthic therapy involves infecting a patient with worms from the helminth family, including hook worms and whipworms. Most of the time, the patient will receive an injection of the worm’s eggs via inoculation. This therapy is not only used to treat Crohn’s disease, but also multiple sclerosis, asthma, and inflammatory bowel disease (IBD), among others.

Hook worms can sometimes cause itching and blistering in the patient, but this side effect is mostly just discomfort. Cutaneous larva migrans is a more concerning side effect, causing a “creeping eruption” that both reddens the skin and causes it to rise. The good news about hook worms is they generally don’t go much deeper than the skin, which helps prevent them from doing further damage.

Hook Worms & Crohn's

In patients with diseases like Crohn’s, hook worms are thought to lessen the body’s autoimmune response to antigens, which in turn reduces infection in the gastrointestinal tract. Some researchers believe that because today’s children aren’t as exposed to infectious diseases as children were in past generations, the incidence of conditions such as Crohn’s in adults has increased. Treatments such as hook worm therapy are now necessary to restore the body’s natural autoimmune balance.

One major problem for Crohn’s patients looking for treatment is that often they will have to travel far to be infected with hook worms. Currently, only one clinic in Tijuana, Mexico, is providing hook worm treatment for Crohn’s. However, as more research is done, there may be an increase in the availability of hook worm therapy.

Helminthic Therapy in the U.S.

Currently, a company called Ovamed is working on getting the necessary approvals for helminthic therapy. In recent years, a San Diego company, Asphelia Pharmaceuticals, began working with Ovamed on researching various forms of helminthictherapy. Asphelia noted that patients infected with hook worms and other helminths tended to be less likely to get diseases such as multiple sclerosis and Crohn’s. The key, Asphelia says, is to find a helminth that has minimal side effects with multiple advantages. Hook worms may be the very helminth researchers are searching for. Aside from the skin issues mentioned above, hook worms can also cause diarrhea, anemia, and weight loss. However, these side effects are generally present in more severe infestations.

Hook Worm Therapy Research

Hook worms are also being researched by a University of Nottingham researcher in England. While hook worms are dangerous in the tropics where infestations are common, scientist David Pritchard had no problems among his patients in controlled experiments, he says. Because the hook worms are instituted in such small numbers, the risks of anemia and infection are smaller, so patients are able to reap benefits without concern of major side effects.

In his tests, Dr. Pritchard found that his subjects showed lower amounts of inflammation in the intestines, which was measured by testing the T-cells of study participants. Those participating in the study also noticed that their allergy symptoms began disappearing. As word spread of the work Dr. Pritchard was doing, he was able to extend his research to other allergy sufferers and he soon became known as the first helminthic therapy researcher to actually infect his subjects with hook worms.

The long-term goal of Dr. Pritchard and other researchers is to track down the reason hook worms and other helminths are so effective, to possibly develop less invasive ways of treating patients suffering from immune system disorders. While many patients may cringe at the thought of being infected with hook worms, the fact that they work in treating patients with asthma, allergies, and other issues should not be minimized.

Side Effects of Hook Worm Therapy

Over time, hook worms can cause side effects that can be more dangerous, including increased risk for anemia. Protein deficiency can also develop, leading to an impairment of mental functioning  and stunting physical growth in some patients. Medications are available to offset these side effects and patients undergoing hook worm therapy may be prescribed iron supplements if anemia is present.