Parasites: How We Contract Them and What They Do to Us
Infectious Diseases

Parasites: How We Contract Them and What They Do to Us

Parasitic infections are much more common than you likely realize.
(Rattiya Thongdumhyu/Shutterstock)
BCDHH
November 03, 2023
Updated:
January 15, 2024
0:00
This is part 1 in Parasites: Our Uninvited Guests

This series will explore the parasites, including what they are, how we get them, and how we get rid of them.

For many Americans, when the word parasite is mentioned, they associate it with traveling overseas and consuming contaminated food or water. However, parasitic infections are much more common than you likely realize.

Parasites are organisms that live on or in a host organism of another species. They depend on their host to survive, pulling nutrients from the host. Parasites vary greatly in size, with some being microscopic and living inside fat or red blood cells, while larger worm-like parasites will survive in the brain, gut, liver, muscles, and other areas of the body.

Major Types of Parasites

There are a wide variety of parasites that can infect humans, but they break down into three distinguishable categories:

Ectoparasites

Ectoparasites are bugs that attach to skin to feed on skin tissue or blood. Examples of these parasites include ticks, mosquitoes, lice, flies, fleas, mites, and bed bugs. Some ectoparasites carry other pathogens, such as Lyme disease from ticks or West Nile virus from mosquitoes, that are transmitted to the host human.

Protozoa

Protozoa parasites are microscopic in size, and they can easily multiply and spread in humans to cause intense health problems. A few common protozoan parasites include:

Blastocystis Hominis: These can be a cause of food sensitivities as a result of a leaky gut.

Plasmodium Falciparum: These cause malaria and are characterized by the host dealing with intense flu-like symptoms.

Babesia Microti: This is a Lyme coinfection that can result in anemia and flu-like symptoms.

Toxoplasma Gondii: This is another Lyme coinfection that causes flu-like symptoms and enlarged lymph nodes.

Helminths

Helminths are parasitic worms, and what most people likely picture when they think of parasites. These parasites are visible to humans without the use of a microscope and vary in size from small to as large as 12 inches long.

Roundworms are a helminth that infects specific areas of the body such as the liver, lungs, intestines, skin, and muscle tissue. Pinworms are a common type of roundworm, roughly the size of a staple and characterized by the female pinworm’s pin-like tail.

Flatworms are characterized by their flattened bodies, as the name suggests. Fluke flatworms often invade the liver, causing damage to bile ducts. They also invade the blood, lungs, and intestines with their leaf-like shape. Tapeworms typically infect the small intestine or gallbladder.

Symptoms

When dealing with troubling symptoms of any kind, it’s important to seek to find the root cause. In many cases, parasites can be the root cause of a wide variety of health complaints. Concerns such as autoimmune conditions, food sensitivities, and gut problems may all be caused by parasites. Symptoms of potential parasite infection are wide ranging, including:
  • Digestive problems, including unexplained constipation, diarrhea, or persistent gas
  • Skin issues, including unexplained rashes, eczema, hives, and itching
  • Muscle and joint pain
  • Fatigue, even when you get enough sleep
  • Never feeling full, even after eating a big meal
  • Constant hunger, even when you’re eating enough
  • Iron deficiency anemia (lab tests show an abnormally low iron level)
  • Trouble falling asleep or waking multiple times a night
  • Grinding your teeth during sleep
  • Unexplained feelings of anxiety
  • Air hunger
  • Past food poisoning after which you haven’t felt right since
  • Recurrent yeast infections
  • Itching of the anus or vagina

Common Sources and Causes of Parasites

As mentioned earlier, contrary to what many believe, you don’t have to travel to a third-world country to pick up a parasite. When traveling internationally, it’s most common to contract a parasite from contaminated water. However, there’s a high chance of contracting parasites right here in the United States.
Millions of Americans struggle with parasitic infections, according to the Centers for Disease Control and Prevention. Many natural health professionals believe that parasites are a significant root cause of chronic symptoms. There are many ways that a person can become vulnerable to a parasitic infection.
Contaminated Water: This can include drinking contaminated water, even municipal tap water, as well as swimming in a contaminated body of water such as a stream, lake, or swimming pool.
Contaminated Food: Foods such as undercooked seafood and meat can be a source of parasites, as can raw fruits and vegetables that haven’t been properly handled and cleaned.
Dysbiosis: Dysbiosis (an imbalance in the gut microbiome) creates the “perfect” terrain for parasites to thrive in, as there isn’t enough beneficial bacteria to fight against the parasites.
Insufficient HCL: As part of the innate immune system, hydrochloric acid (HCL) in the stomach is the first line of defense when it comes to the food and beverages that we consume. The acidity of HCL kills pathogens that may enter the body through food and drink. Additionally, because digestion is a top-down process, lack of proper HCL secretion can cause food to not be broken down properly and thus lead to poor nutrient assimilation. Furthermore, this leaves the body more susceptible to pathogens.
Immune Insufficiency: An individual who’s carrying a high toxic burden, is malnourished, is dealing with high stress levels, or has chronic immune challenges may be more susceptible to a parasitic infection.
Antibiotic and Immunosuppressive Drugs: Antibiotics and other immunosuppressive drugs cause damage and ultimately destroy good gut bacteria. This creates an environment for parasites to proliferate in, essentially opening the door for them to cause long-term chronic health conditions.
Pets: Humans can contract parasites from animals, including pets. For example, toxoplasma gondii infection can occur from handling contaminated kitty litter.
Surfaces: Surfaces such as toys, bedding, door handles, toilet seats, soil, and other objects can be contaminated with parasite eggs.
Foreign Travel: Consuming contaminated food and water when traveling to foreign countries can be a source of parasites. Additionally, visiting areas with poor sanitation or where other humans and animals are practicing poor hygiene can expose one to a parasitic infection.

Testing

In the conventional and functional medicine world, stool testing is often the first test that providers choose to assess for parasites. Unfortunately, stool testing can be incredibly unreliable when it comes to the hundreds of species that could be inhabiting a human. It’s extremely easy for labs to overlook parasites that may be in the stool, but it’s also possible that not all parasites are living in the colon. In some cases, this is because of parasites attaching themselves to the intestinal lining.

Blood tests are another testing option but still are unable to test for every single type of parasite. Typically, blood tests test for visible parasites, antibodies, and eosinophils and monocytes.

Visible Parasites

Testing for visible parasites often involves a blood smear examined under a microscope, with the lab technician looking for parasites that reside in the blood. This can be a successful method of identifying Babesia (Lyme coinfection) or the parasite that causes malaria, Plasmodium.

Antibodies

The immune system develops antibodies to fight off a parasitic infection, so a blood test can be useful in checking for elevated antibodies indicating potential parasites.

Eosinophils and Monocytes

Elevated eosinophils or monocytes (white blood cell types) markers in a blood test could indicate that the body is struggling with parasites. Keep in mind that elevated eosinophils could also indicate allergies, malignancy, viral infections, etc.

If eosinophils come back normal and you’re experiencing symptoms, it’s worth discussing options with a clinician. Some will argue that it isn’t necessary to kill parasites when eosinophils aren’t showing activity, yet every human has some level of parasitic activity. For this reason, many clinicians will go by symptoms when assessing whether or not parasites are a concern for an individual.

If you suspect a parasite infection or have been diagnosed with one, it can be discouraging and overwhelming to know where to start with healing. While parasites can cause a wide variety of long-term, chronic health problems, they’re often treatable and preventable. With an effective healing protocol, many health concerns and symptoms can be alleviated.

Parasites struggle to proliferate in a healthy host, so essentially, the healthier you are, the less likely you are to be susceptible to parasite overgrowth.