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Six Commonly Missed Diagnoses: Parasites

Posted 06/11/2012

If internet scare tactics from companies selling herbal supplements for parasites weren’t enough, the cable TV show “Monsters Inside Me” with its toe-curling film clips has cinched it. We’re in a new “Alien versus Predator” mode, though you might ask which one is us and which them. Those really large parasites you’ll see wriggling across your flat-screen Sony as you scream “I can’t watch this!” (but do) are all helminths, better known as worms. Worldwide, intestinal worm infestation is pretty common, but mainly in underdeveloped countries where people have a bit more contact with raw sewage than we do here in Chicago (unless you swim in the river).

The helminths are the stars of “Monsters Inside Me” because they’re big enough to see without a microscope. When patients ask me to check them for parasites or report “something wriggling in my toilet,” it’s the helminths they have in mind. Obsessing about parasites, despite your best efforts your mind keeps rewinding to John Hurt’s untimely and utterly galvanizing death-by-parasite in the original “Alien.”

Despite studying parasites of all stripes in medical school and testing thousands of patients for them, I think I’ve seen fewer than a dozen cases of intestinal helminth infestation in my entire career. Most of these were in children who’d picked up a pinworm infection (E. vermicularis), little ones being very democratic about their anal hygiene. Pinworm intestinal infection is generally harmless, its main symptom itching around the anus. Treatment using a worm killer, called a vermifuge, wipes out the pinworms after one or two doses.

A second infection is hookworm, once prevalent in the southern US and caused by a combination of inadequate plumbing and a preference for barefootedness. Probably most of the characters in Erskine Caldwell’s novels like God’s Little Acre and Tobacco Road had hookworm. Through a very circuitous route, the worm enters through skin and ends up in the intestines. Once diagnosed it’s easy to treat. I’ve seen exactly one case of hookworm, in a returning Peace Corps worker who should have known better.

Other less common helminths are roundworm (Ascaris lumbricoides) and the scary looking tapeworm (several species), once common when we were sloppy with our meat, poultry, and fish preparation. Jewish grandmothers and great-grandmothers were frequently victims of fish tapeworm (Diphyllobothrium), infected by sampling their uncooked haddock while making gefilte fish. These days it’s our sushi/sashimi addiction that renders us susceptible to fish tapeworm. Given the amount of sushi we eat, though, the actual incidence of tapeworm is extremely rare.

What’s living inside me?
It’s these worms (and that TV show) that cause people to lie awake at night wondering what’s living inside them. Well stop wondering and go back to sleep. I want to emphasize that all of these are (a) rare, (b) easy to diagnose, and (c) fairly easy to treat.

You’ll not see the single-celled protozoa infestation stories much on TV. Characters visible only with a microscope just lack the panache, the stage presence, to terrify. However, it’s infections with these little buggers that we’re discussing today.

Doctors are in full agreement that two specific intestinal protozoa–ameba (E. histolytica) and giardia (G. Lamblia)–are troublemakers. Both are acquired by the unappetizing “fecal-oral” route of transmission, which is exactly what it sounds like (now go wash your hands). Most people don’t recall just where they might have acquired amebiasis or giardiasis, but as a general rule you get it from someone who didn’t wash hands after using the toilet. Campers occasionally get giardiasis from drinking water downstream from a herd of cattle. Both infections are manifested by a sudden onset of diarrhea. In the case of giardia, it can be quite explosive and lead to dehydration. Just about anyone who has sudden diarrhea after travelling that doesn’t respond to the routine antibiotics for traveler’s diarrhea (Cipro, Xifaxan, Flagyl) should be tested for these protozoa.

Less agreement among physicians occurs with three other parasites: Endolimax nana, Dientamoeba fragilis, and Blastocystis hominis. For years, these three were considered harmless. Unfortunately, most lab technicians assigned to poop examination (a part-time job I myself held during medical school) are not well-trained in checking for them. It’s very likely a reasonable percentage of patients written off as irritable bowel syndrome/diarrhea dominant actually have an infection with one of these three. The main clues that their IBS is protozoan in origin are that the diarrhea emerges as a new event in their lives, unrelated to stress, and isn’t triggered by any particular foods. “I got traveler’s diarrhea while in Mexico and despite antibiotics, it never went away,” sends me a clear signal to check for parasites.

An easy fix
The combination of lab techs missing these parasites and physician disbelief that the three are troublemakers qualifies parasites for inclusion on our Commonly Missed Diagnosis list. Most of the really good parasite labs–Genova (formerly Great Smokies), Meta Metrix, Doctor’s Data, Meridian Valley–are virtually never used by physicians affiliated with large US medical centers, these doctors preferring to blindly trust their hospital labs. I remember one patient telling me how she handed her Genova parasite test result (showing heavy counts of dientamoeba and blastocystis) to her Northwestern gastroenterologist. He saw the lab and tossed it back without reading it, saying “This is garbage. Never heard of this lab. Bet you got it from a chiropractor.”  This, of course, can potentially lead to years of unnecessary diarrhea.

Nutritional guru Alan Gaby, MD, once remarked that if a patient has no access to one of the parasitology labs, she should take her specimen to a veterinarian and palm off her poop as belonging to her beloved pet. Veterinarians are much better than conventional physicians at diagnosing parasites.

Once a diagnosis of any of the three parasites is made, treatment is generally straightforward with an anti-parasite med like Flagyl (metronidazole), an antibiotic like the sulfa drug Bactrim, or a combination of these. After treatment for any parasite, whether it’s a helminth (worm) or a protozoan, a follow-up stool collection is mandatory to ensure it’s been completely eradicated.

Sleep well…

Be well,

David Edelberg, MD

Posted in Blog, Knowledge Base, P, S Tagged with: , , , , , , ,
11 comments on “Six Commonly Missed Diagnoses: Parasites
  1. JasonMChicago says:

    Parasites are very, very common here in the US. I personally suffered many years not knowing about these little creatures. I find it ironic that we de-worm our dogs twice a year but never consider this for ourselves. Humans should de-worm too… even in industrialized countries.

  2. Carol says:

    Re: gastroenterologists comment about “garbage.” (See prior article on “Arrogant Doctors.”)

  3. Margo says:

    Actually, veterinarians miss macroparasites a fair amount of times, and not for lack of looking but rather limitation of the test used.

    One typical way to detect macroparasites in pets (such as roundworms, the subject of this story) is to look for ova (eggs) in the pet’s stool sample. But these don’t always turn up, even with multiple samples. Several years ago, when my dog suffered from intermittent diarrhea over several months, I didn’t get an accurate diagnosis from the vet until I found a very much alive and kicking 4-inch roundworm in the dog’s stool, which I bagged and later handed to my vet. “Sterile females or males only” was my vet’s mumbled explanation why the worms weren’t detected previously despite several specimens having been brought in; he added that this “occasionally happens”. Happy ending: once diagnosed, medication quickly solved that problem and the dog was back to normal.

    Wonder if this same test limitation doesn’t occur in people, as well, even when a well-informed physician wil take the time to order tests to look for parasites as done by a reputable lab?

  4. Bee says:

    Which stool test does your office recommend?

    Which of these is best: Genova Comprehensive Digestive Stool Analysis 2.0 W/Parasitology


    Doctor’s data Comprehensive Stool Analysis w/Parasitology x3


  5. Dr. R says:

    We use Meridian Labs which outsources to Doctor’s Data for their stool analysis.

  6. Sam says:

    I have been going through a terrible ordeal. After years of research and recently a severe cold with a cough that has lingered for months I have concluded I may have an infestation. When I reflect back over the years I really cannot pin point when or how whatever is going on may have started. I am starting to believe I have had it for years and due to the natural aging process I am now experiencing more symptoms than ever. I am having a terrible time trying to convince my family care physician that something is terribly wrong despite a laundry list of symptoms. I do not understand the dismissive demeanor of the physicians over the years. We have all seen or read about illnesses that may occur out of the norm. I find it extremely ironic for professions that studied science as a major and refuse to acknowledge mutations occur and with the ever changing microbial word anything can happen to anyone.

    Here is a list of my symptoms as of today:

    Cough with an odor from my throat or lungs
    Four staph infections in the last two years
    Sore muscles, lungs..sometimes muscle fatigue to the point I can not stand or walk
    Lethargy, insomnia, constipation, severe bloating, gas, diarrhea
    Vaginal odor that started a few years ago. Boric Acid inserts eliminate this problem but must be used weekly.
    The odor will return or become more prominent after my cycle or intercourse.
    Watering and irritation of my left eye, eyesight has deteriorated rapidly over the past 4 years
    Athletes foot on both feet and my right hand
    Itchy rectum particularly at night
    Pain in my joints particularly my back
    There is a specific area of my back on the left side under my shoulder blade that feels like a tight muscle that needs to release. It sometimes takes my breath away if I breathe too deeply.
    Hard lumps under my skin in areas all over my body.
    Pain in my tailbone that can be debilitating.
    Poor memory
    Pain particularly in my right buttock down into my leg. Pain and or soreness in my forearms like I have spent all day doing exercises on just these muscles.
    Index, middle, and ring finger on my left hand has sharp burning sensation only present on the top of each finger..this one, as well as the forearm pain has subsided greatly with self massage.

    I have found intermittent relief from fatigue and muscle pain using magnesium chelated and d ribose.

    I was diagnosed with IBS in 2008, after years of diet and lifestyle changes was symptom free for a couple of years.

    I find this list ridiculous to say the least. I feel like a crazy person with hypochondria. After all the research I realize these symptoms are listed in tons of diagnosis. Because of this coupled with a lack of physicians in my area to help rule out anything I have been coping with a dark, gloomy, hopeless quality of life.

    I find myself analysing doctor visits I have experienced in recent years. I am left with burning questions and self blame.

    Sorry for the lengthy post, I do feel a little better now that I have made a list and shared it with someone. I would never take this entire list to a doctor for fear of judgement and invalidation.

  7. Silvia says:

    Sam, I’m sorry for how you feel. You explained your systems & concerns very well. I have muscle, joint pain, severe abdominal distention, insomia, & other less bothersome issues. I often find myself wondering if sharing all the info is more confusing or beneficial at dr apt. I’ve had it go both ways. Its especially concerning when visiting a specialist. I found a GP doctor that understand he doesn’t always have the answer but that doesn’t mean syptoms don’t exist. We keep trying new things. Thanks for reminding me to get back on d ribose/ Corvalen. It did help a little with muscle pain. Now I’m on riflaxin to see if my tesinal issue improves. Thank you for helping by sharing your post.

  8. Chandra says:

    I have all the symptoms Sam states plus I cough up mucous when I cough and have to spit it up constantly and this round of symptoms I have severe left side deep in my chest pains it hits hard subsides then returns. This has been going on for 2 days this round. It started over a year ago. I seek medical help and get told it’s in my head they can’t find anything I’m paranoid or it’s a drug addiction problem.I have a girlfriend who has the same or worse symptoms she gets told the same thing by completely different doctors. I am scared and feel all alone in this nightmare. They almost had me convinced I was dillusional, I know this is real but have also been shamed by many even family that I’m overreacting it’s got to be me for some reason or another. I feel if I don’t get help I will end up dying especially as we speak with these severe chest ie heart pains because I have done a lot of researching on the Internet and know they get to the heart and brain which can be fatal if not treated.I have little money to even get Dr. Clark’s cleanse or the diagnose me report. But I will not give up until I am dead. Why doesn’t traditional medicine educate the medical community more on parasites? I do not understand…I need help but no one I have seen will take me serious. Suggestions please anyone…Thank you for reading

  9. Hello, the whole thing is going perfectly here and ofcourse
    every one is sharing facts, that’s genuinely good, keep up writing.

  10. ray says:

    I have shared similar symptoms and have also had wholly inept assistance from mainstream biomedicine. However I have started to use diamatceous earth daily to detox from from parasites bacteria yeast endotoxins with progressive improvement

  11. Alana says:

    For all of you who are suffering… with so many ignorant doctors our there: please educate on yeast overgrowth in the body! Yeast can cause all these symptoms & more! Science is now making the connection between so many illnesses & yeast – even cancer! Do your research. There are even great videos on Youtube. STAY COMPLETELY AWAY FROM SUGAR & SIMPLE CARBS – these feed yeast!

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