Tag: parasite & ova test

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Pathology labs are utterly useless

Pathology labs are so utterly useless, it was quite disturbing to discover out how bad they are, repeatedly and in so many ways for so many types of tests.
When I first got back from Africa convinced I had been successful infecting myself with hookworm, because of multiple rashes and a night of violent coughing, I tested negative 3 times in a row at a lab in California.
I was convinced I had failed. I was crushed. I was broke.
Then my allergies and then my asthma went and I began to wonder, and I bought a microscope.
After that, I had multiple tests over the next year or so with different labs looking for one that knew what they were doing. I was being asked to prove I had hookworm, and everyone thought as I had that it was a simple test.
You can imagine, back then there were no blogs, almost no news or research, and a lot of people thought I was lying. After all, where were the test results?
Later on, I wanted to be able to refer clients to an independent lab, a lot of people were preoccupied with McMaster egg counts, worthless though they are. As well as to confirm their ongoing infection with hookworm.
I did not want to do stool tests because it was going to be believed I was just making results up. A lot of people did not believe we actually had worms back then is what I mean. One client when we first started providing whipworm who lived in San Francisco, ninety miles to the north, insisted on visiting to view some ova through a microscope. Some decent independent testing would have been useful.

Some decent independent testing would have been useful.
I have only ever tested positive once with a third party, the Clinic associated with the Liverpool School of Tropical Medicine, this was after we had had to leave the USA and fully four plus years after I went to Africa and more than two years after I went to Belize. That clinic even gave decent estimates of my worm burden for both Hookworms and Whipworms, as in Heavy of hookworm and moderate for whipworm.I imagine lab techs are people who “know” no one in the States or Europe can possible have a helminth infestation.

I imagine lab techs are people who “know” no one in the States or Europe can possible have a helminth infestation.

So when a sample comes in from someone wanting a test for hookworms and they say they have not travelled abroad in the last three years, in the Tech’s mind the person asking for the test has to be obsessive, a Hulda Clarke acolyte.The Tech does, at best, a cursory examination of a single slide, wretches a few times, and bins the sample, ticks “Negative” on the carbon paper form and then furiously washes their hands, and liberally applies hand

The Tech does, at best, a cursory examination of a single slide, wretches a few times, and bins the sample, ticks “Negative” on the carbon paper form and then furiously washes their hands, and liberally applies hand sanitiser.That is how I imagine it goes most of the time, at $90 a pop.

That is how I imagine it goes most of the time, at $90 a pop, with three tests at two week intervals the recommended way to test for parasites.

We had another experience where a client went to their doctor, the client was nuts by the way, convinced they had a deficiency disease, and the Dr. ordered blood work.At the time I was working with a clinical pathologist, someone who ordered and interpreted sophisticated tests for doctors, and had done so for years working for the National Health Service here in the UK.

At the time I was working with a clinical pathologist, someone who ordered and interpreted sophisticated tests for doctors, and had done so for years working for the National Health Service here in the UK.On the basis of the blood

On the basis of the blood results the doctor ordered iron infusions, and a regimen of supplementation for things like magnesium.The client went nuts.

The client went nuts.The client very shrilly blamed her predicament on hookworms and on me, it was still early days so I wasn’t equipped to refute both her and a doctor or so I thought. She was fulminating online and everywhere that we were a threat to life and limb, grossly irresponsible, etc., etc.

The client very shrilly blamed her predicament on hookworms and on me, it was still early days so I wasn’t equipped to refute both her and a doctor or so I thought. She was fulminating online and everywhere that we were a threat to life and limb, grossly irresponsible, etc., etc.So we obtained a copy from her of her blood results, and according to the clinical pathologist had they been correct the blood could only have been drawn from a corpse.

So we obtained a copy from her of her blood results, and according to the clinical pathologist had they been correct the blood could only have been drawn from a corpse.The Dr. had not noticed, or more likely had decided it was easier to treat a condition that did not exist than to confront the lunatic.

The Dr. had not noticed, or more likely had decided it was easier to treat a condition that did not exist than to confront the lunatic.The lesson of this story is that you should always obtain a confirming test when lab results indicate anything other than a mild course of treatment, iron infusions are not mild. You can apply the same reasoning to the opinions of doctors. I never go myself, but when I do and if a diagnosis is rendered I will definitely be getting a second opinion and a new set of tests.

The lesson of this story is that you should always obtain a confirming test when lab results indicate anything other than a mild course of treatment, iron infusions are not mild. You can apply the same reasoning to the opinions of doctors. I never go myself, but when I do and if a diagnosis is rendered I will definitely be getting a second opinion and a new set of tests.

If you doubt me maybe you should do some searching, here is one link I found by Googling “number of misdiagnoses per year USA”.

http://ow.ly/KcPw309TWaq

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Why McMaster ova counts are largely worthless for detecting changes in helminth population

The Argument Against Egg Counts as an Indicator of Helminth Number

  • Parasitology texts note that per day female hookworm and whipworm ova production varies from 2,000 to 20,000 total. For this reason alone any estimate based on an ova count must have a variance of x10. That is the answer can only be expressed as a range, with the higher end of the range being ten times the low end. So a typical answer would be “from 20-200 hookworm”. Fairly useless, particularly if you are trying to detect the loss of one or two hookworm. On this basis alone the test is too crude for the purposes most with deliberate helminth infections are trying to use it for.
  • Egg counts are a measure of density. So any count is going to be affected by things like the speed of material through the intestines (constipation or diarrhoea at the extremes), amount eaten, amount of fluid drunk, fibre content of food, etc. If you think of the extremes one can see this is going to have an enormous impact on density of ova per gram of faeces. Different foods and drugs affect the speed of material through the intestines.
  • Any count depends on extreme precision and replication of methods and precision from test-to-test. Only an experienced lab technician is capable of accurately counting ova in stool, stains are no aid and identifying each and every ova in a gram of faeces is difficult work. In someone producing 100 ova per gram .1 grams will contain 10 ova, so the slightest variation in weight can have a big effect on the number observed, that effect then being amplified by the multipliers used to derive worm population from egg counts.
    Ova production varies tremendously with time. Hookworm ova production falls by an estimated 50% about one year after infection. But there is little information on whether this is invariably 50% or exactly when it happens or how fast.

  • Ova production in all helminths is affected by various drugs, some known, some inevitably unstudied. So, antibiotic use so profoundly reduces ova production that parasitology texts recommend not doing ova tests for two weeks after the subject stops taking the antibiotics. Other drugs almost certainly have various effects as well.
  • McMaster egg counts have been abandoned by doctors of veterinary medicine as being useless as a practical tool for estimating worm numbers. They would know.
  • Most people using helminthic therapy, if using N. americanus or T. trichiura, know how many helminths they received. So the only purpose of ova counts is to monitor infection levels. But given all the other factors noted here the test is not sensitive enough to detect even a relatively large change in numbers.

    Egg counts can be used as a broad indicator of worm burden, but only as an indicator. McMaster egg counts were intended for use to determine whether someone has a heavy, moderate or light infection, so appropriate treatment (as in elimination except in light infections) could be prescribed.

    Researchers use egg density measurements in studies to monitor worm burden in their study subjects, but they have specialised equipment and the training to do so reliably and consistently. Even then they cannot indicate much, and beside most studies continue for far less than one year. So any change they are likely to detect would be gross, that is loss of worms. Which is undoubtedly what they are primarily looking for.

    The only method with any real utility to determine helminth population is endoscopy for hookworm and colonoscopy for whipworm.

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Why McMaster ova counts are largely worthless for detecting changes in helminth population

The Argument Against Egg Counts as an Indicator of Helminth Number

  • Parasitology texts note that per day female hookworm and whipworm ova production varies from 2,000 to 20,000 total. For this reason alone any estimate based on an ova count must have a variance of x10. That is the answer can only be expressed as a range, with the higher end of the range being ten times the low end. So a typical answer would be “from 20-200 hookworm”. Fairly useless, particularly if you are trying to detect the loss of one or two hookworm. On this basis alone the test is too crude for the purposes most with deliberate helminth infections are trying to use it for.
  • Egg counts are a measure of density. So any count is going to be affected by things like the speed of material through the intestines (constipation or diarrhoea at the extremes), amount eaten, amount of fluid drunk, fibre content of food, etc. If you think of the extremes one can see this is going to have an enormous impact on density of ova per gram of faeces. Different foods and drugs affect the speed of material through the intestines.
  • Any count depends on extreme precision and replication of methods and precision from test-to-test. Only an experienced lab technician is capable of accurately counting ova in stool, stains are no aid and identifying each and every ova in a gram of faeces is difficult work. In someone producing 100 ova per gram .1 grams will contain 10 ova, so the slightest variation in weight can have a big effect on the number observed, that effect then being amplified by the multipliers used to derive worm population from egg counts.
  • Ova production varies tremendously with time. Hookworm ova production falls by an estimated 50% about one year after infection. But there is little information on whether this is invariably 50% or exactly when it happens or how fast.
  • Ova production in all helminths is affected by various drugs, some known, some inevitably unstudied. So, antibiotic use so profoundly reduces ova production that parasitology texts recommend not doing ova tests for two weeks after the subject stops taking the antibiotics. Other drugs almost certainly have various effects as well.
  • McMaster egg counts have been abandoned by doctors of veterinary medicine as being useless as a practical tool for estimating worm numbers. They would know.
  • Most people using helminthic therapy, if using N. americanus or T. trichiura, know how many helminths they received. So the only purpose of ova counts is to monitor infection levels. But given all the other factors noted here the test is not sensitive enough to detect even a relatively large change in numbers.

    Egg counts can be used as a broad indicator of worm burden, but only as an indicator. McMaster egg counts were intended for use to determine whether someone has a heavy, moderate or light infection, so appropriate treatment (as in elimination except in light infections) could be prescribed.

    Researchers use egg density measurements in studies to monitor worm burden in their study subjects, but they have specialised equipment and the training to do so reliably and consistently. Even then they cannot indicate much, and beside most studies continue for far less than one year. So any change they are likely to detect would be gross, that is loss of worms. Which is undoubtedly what they are primarily looking for.

    The only method with any real utility to determine helminth population is endoscopy for hookworm and colonoscopy for whipworm.