*Note: I chose the cute illustrated worm so that I wouldn’t give you nightmares. You’re welcome.*
We know a lot in our modern world about testing for some types of infectious organisms—we can culture bacteria, and test antibodies for viruses (though sometimes interpretations of these results can be tricky.) Even though the traditional medical community doesn’t put a lot of stock in fungal infections for the non-immunocompromised population, it’s still possible to test for yeast, as well—and we can even test for and identify mold, for the most part.
But parasites are some of those infectious organisms that tend to defy direct diagnosis in many cases. Because of this, those of us in the developed world tend to assume they’re not an issue—but they are. Even in the United States, parasites are quite common. Even the CDC thinks so.
So how can we tell if parasites are a problem for us?
Symptoms of Parasites
Technically, a parasite is any organism that lives in or on another organism, and steals nutrition from the host at the host’s expense. By this definition, the term encompasses all the microscopic organisms listed above (viruses, bacteria, and fungi). But usually when we talk about parasites, we mean organisms other than these three. We generally refer to parasites as microscopic intracellular or intercellular parasites (protozoa), macroscopic worms (helminths), and ectoparasites, which can be microscopic or macroscopic (mites, ticks, etc).
Which symptoms you will experience depends upon the organism, of course—and given the range of types of organisms, there is of course a very broad range of symptoms that can be attributed to parasites. But here’s some of the big ones.
- Gut distress: constipation or diarrhea, gas and bloating (especially if other causes have been ruled out)
- Rashes, eczema, or hives.
- Loss of appetite. This seems to be secondary to gut distress. (Conversely, I’ve heard that ravenous hunger is a sign of parasites, but I wasn’t able to find studies to back that up.)
- Grinding your teeth at night.
- Chronic fatigue that is otherwise unexplained.
- Insomnia, otherwise unexplained.
- Iron deficiency anemia.
- Infertility, otherwise unexplained. This can be male or female infertility.
This questionnaire can help you determine how likely it is that parasites could be part of your problem. It encompasses a lot of fairly general symptoms that could be attributed to a lot of things, but it’s probably more useful if you’ve already ruled out other causes for the above symptoms (or if you traveled overseas, had a bout of food poisoning, went camping, swam in questionable waters, or got a new pet shortly before symptoms began–see below.)
Common Parasites and How You Get Them
Most of us know that overseas travel, or swimming in lakes or streams can mean parasite exposure. But as mentioned earlier, even those of us in the US (and without adventurous proclivities) can be exposed. This can occur via:
- Tap water. This is a fecal/oral process, and organisms most commonly transmitted are Cryptosporidium and Giardia.
- Contaminated food. This is also fecal/oral, and can transmit many different types of parasites. It can occur if you don’t wash your fruits and veggies well—or via unwashed hands of those preparing or serving the food. Consuming raw or underprepared beef or pork can also lead to tapeworm infections.
- Tick bites. While ticks are most infamous for transmitting Lyme Disease caused by bacteria in the Borrelia family (there are 300 strains we know of so far), they also can transmit parasites—the most common of which are Bartonella and Babesia.
- Pets. Dogs and cats especially can be contaminated with tapeworms. Most of the time the animal does not transmit worms to its owners, unless the animal also has fleas, and the owner accidentally swallows one.
- Walking barefoot outside. Helminths called nematodes live in the soil, and can burrow through the skin. (So if you’re camping by a lake, wear shoes.)
How to Test For Parasites
The first clue that you might need to do some further investigating for parasites might come via a CBC (Complete Blood Count): elevated eosinophils are a type of white blood cell that can elevate with parasite infection. Once the infection is chronic, however, eosinophils may not remain elevated.
Another blood test that might help point you in the direction of a parasite might be elevated total IgE antibodies. These are the same immunoglobulins responsible for hypersensitivity allergic responses, but they also elevate with parasitic infection.
Once you know parasites might be an issue, there are a few options, though some are better than others.
A colonoscopy or endoscopy isn’t going to catch any of the microscopic parasites, though the doctor might see larger worms that way.
Blood testing is useful for blood-borne parasites, but antibody testing is limited and often can be a false negative, depending on the life cycle of the organism. For organisms such as babesia and bartonella, blood testing is far more accurate through specialty labs.
Stool testing can be PCR (which looks for the DNA of the organisms) or ova and parasite testing (manually staining the feces and looking at it under a microscope.) Each of these tests has its limitations and benefits. On one hand, PCR testing is not dependent on the skill of the technician. If the organism is there, or has ever been there, the test will pick it up. On the down side, it may be positive even if the infection is no longer current, and you will only find organisms you’re specifically looking for (which may encompass the most common organisms, but might miss others).
Collection for an ova and parasite test occurs over a period of several days (to account for the variability of parasitic life cycles). It can be very accurate, or less so—depending on the skill of the technician. So it’s helpful to run this test through a lab that specializes in parasitology.
How to Treat Parasites
If you can identify the parasitic organism, in many cases, pharmaceuticals are the way to go—though they can carry harsh side effects. Other options include anti-parasitic herbal combinations (which are effective for some organisms but not others—different herbs have different indications), or Low Dose Immunotherapy (LDI). LDI helps to induce immune tolerance to the organisms, for Westerners who lack the tolerance common to populations with more endemic parasites.