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Adrienne Dellwo

Bowel Parasite May Lead to Chronic Fatigue Syndrome

By February 15, 2012

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Research Brief

A new study out of Norway suggests that the bowel parasite Giardia lamblia lead to an increased rate of chronic fatigue syndrome (ME/CFS).

Researchers focused on a population that was hard hit by a waterborne outbreak of Giardia enteritis, which included 1,262 people. They first identified a group of 96 people with long-lasting post-infectious fatigue, then evaluated this group for ME/CFS.

Of those 96 people, 58 (60%) were diagnosed with ME/CFS. That's about 4.5% of the people affected by the outbreak.

The study was conducted just over 2.5 years after the outbreak. Over that time, 57% those who's developed ME/CFS said their illness had gradually worsened, 28% said it had stayed constant, and 16% said they'd seen improvement.

Researchers noted a distinctive pattern of impairment that included poorer physical function, more fatigue and low energy, and lower rates of social functioning.

Learn more or join the conversation!


Photo Tom Le Goff/Getty Images

February 15, 2012 at 6:25 am
(1) BendigoLioness says:

I had giardia about 5-years ago; had ME/CFS for nearly 4-years. Interested to hear more from this study!

February 15, 2012 at 8:24 am
(2) Jackie says:

I am very interested in more information from this study. This may explain why when I take fiber and probiotics along with my nutritionals there is incredible improvement. Poor digestion from beginning to end causes more symptoms. Hope to hear more soon.

February 15, 2012 at 9:59 am
(3) Rachael says:

I wish they would back away from this one cause, and one cause only theory for CFS. There are as many causes for CFS as there are stories from the people who became sick; all under different circumstances.. Autoimmune diseases (like I believe CFS to be) do not have one specific cause, rather there is often a combination of factors involved:

* Family or Personal History of Autoimmune Disease
Many, if not most autoimmune diseases, have a genetic or hereditary basis. This means that if you have a family member with an autoimmune disease, you are at an increased risk of developing an autoimmune condition as well. And it does not have to be the same disease – one relative may have autoimmune thyroid disease, another multiple sclerosis, and another inflammatory bowel disease.

*Gender or Hormonal Status
Seventy-five percent of autoimmune diseases occur in women, and most frequently during the childbearing years. Higher estrogen levels seem to stimulate the immune system, which may explain why men are less affected.

*Bacterial and Viral Infections and Illnesses
Viruses, bacteria and mycoplasma, a type of small-cell bacteria, are implicated in autoimmune diseases. Often a bout of illness with a virus such as the Epstein- Barr virus triggers the onset of an autoimmune disease.

plus *Toxic Metal Exposure, *Toxic Chemical Exposure, *Vaccinations/Immunizations, *Stress and Trauma, *Smoking, *Nutritional Deficiencies

Source: http://www.evenbetterhealth.com/autoimmune-disease-causes.php

February 15, 2012 at 11:45 am
(4) Barbara Bright says:

This study figures. Our dog had successive bouts of giardia while I was recovering from cancer treatment. My recovery stalled and then went backwards. I had constant stomach/digestive problems during that time, but was never tested. Now I think maybe I should have been. Would giardia stay in the system/leave a trace after 4 years?

BTW, While I don’t subscribe to the ‘one cause’ theory for ME, I equally don’t think heredity for auto-immune has much to do with it. I work with an ME support organisation and have hosted forums for patient discussion. When discussing the factors patients believe had a bearing on their illness, heredity for autoimmune conditions hardly figures, whereas potential for onward infection to children (as with HIV) seems to be a biggie.

February 15, 2012 at 12:27 pm
(5) Winaker says:

I find this very interesting as I had giardia before as well and suffer from cfs. Having had auto immune issues for years I believe there is definitely an underlying virus that cause these issues. As far as the comment on genetics, I don’t believe this theory for a second. I’ve encountered too many people in the last few years that have Lupus, MS and Fibro that NO one in theirhas any autoimmune disorders or disease that are even related to their diagnosis/disease.

February 15, 2012 at 12:35 pm
(6) Rachael says:

Barbara Bright said: “When discussing the factors patients believe had a bearing on their illness, heredity for autoimmune conditions hardly figures, whereas potential for onward infection to children (as with HIV) seems to be a biggie.”
It depends on the studies, and your own symptoms. I actually don’t think we all have the same illness. My own problems are definitely caused by an up-regulated immune system, while others seem to be suffering from a suppressed, or poor immune-response. It will be nice when there is finally a test to see just what is actually going on in each individual and if we actually all have the same illness. I don’t believe we do!

Is Chronic Fatigue Syndrome (ME/CFS) an Auto-immune Disorder? by Cort Johnson


February 15, 2012 at 12:42 pm
(7) Rachael says:

Barbara Bright: Read my comments – below the article. “Is Chronic Fatigue Syndrome (ME/CFS) an Auto-immune Disorder?” by Cort Johnson


We all have different reasons for believing what we do about this illness.

February 15, 2012 at 2:42 pm
(8) maria says:

I also believe more in this theory rather than heredity one,since i came down with severe GI infection that wouldnot go away rather got worse over time,i suffered for 3 months almost,never completely recovered ,was also pregnant at the time of infection so thought maybe fatigue and pain starting due to pregnancy ,but its been 6 years now and i have gone from being 100% healthy to bed ridden and friendless. ( I consider myself lucky when i am able to sit and eat a meal)

February 15, 2012 at 3:05 pm
(9) Kc says:

I know its hereditary. I was the most active and healthiest person I know before getting this disease which my mother has had for 20 years. It seems all the people I talk to on facebook with cfs have a mother/grandmother, sister, cousin, etc. It is mostly seen mother/daughter relationships from what I have read and those I talk with though. I think its something that triggers it but the root may very well be the same with us all. Cfs is also one of the most over-diagnosed and under-diagnosed diseases out there. I know too many people who are JUST tired who have been diagnosed with this when they have no other symptoms and go on to live a totally normal life, at time just changing their diet has improved their fatigue. On the other hand there are people who have been to doctor after doctor unable to find one with an understanding of this disease therefor get improper care and wrong answers.

February 15, 2012 at 3:16 pm
(10) MissyD says:

It does make sense as “a” trigger for CFS. I happen to agree with Rachael that CFS may have multiple factors that contribute. One factor that is not mentioned is stress. Personally, I believe that all these factors may set someone up for this horrible illness. That would also explain the study that shows childhood abuse as a contributing factor IN SOME PEOPLE. If you have enough going against you, stress, genetic predisposition, environmental factors, hormonal status, and then you add some kind of pathogen…..wham! That is my theory anyway. I have often wondered about giardia as we live on a lake, and while we drink bottled water ( the big 5 gallon returnable bottles, don’t think we are plastic consuming terrorists, please) we don’t treat our tap water that we use for washing, toothbrushing etc. And, like most, if not all northern lakes, we have a healthy contingent of beavers that shares the lake with us, and they are notorious for carrying giardia. Perhaps I should get tested……..

February 15, 2012 at 7:33 pm
(11) Adrienne Dellwo says:

Actually, I don’t think any researchers are suggesting that there’s a single cause of chronic fatigue syndrome, which is why I said it could be “a cause,” not “the cause.” The medical community in general is moving away from the idea that any one thing can cause most diseases and talking instead about “causal factors.”

First, each case is generally believed to be caused by multiple factors, likely starting with a genetic predisposition and including something such as an infectious agent or toxin along with other factors.

Second, it’s likely that many different combinations of factors can result in what’s thought of as ME/CFS – but which is, in reality, probably a collection of highly similar illnesses that each need to be diagnosed and treated differently. Several researchers are working to identify subgroups, but it’s a slow process. I believe, however, that 10 years from now we’ll be in much better shape in this area.

February 15, 2012 at 7:50 pm
(12) Lee Ann says:

I had giarrdia (sp) in 1989. Took flagyl and it went away. I was diagnosed with fibromyalgia in 2003. Wonder if there’s a connection?

February 17, 2012 at 4:02 pm
(13) edie says:

is this bowel disease same as pylori stomach infection? cause i had that and then after that i started getting symptoms. i am now diagnosed with cfs, fibromyalgia, and myofascial pain, among other things, and am bedridden for the past three years. was just wondering if anyone knew if they were similar in any way?

February 17, 2012 at 4:34 pm
(14) Tammie Page says:


no they are not the same……h pylori is the bacteria responsible for ulcers, but most people have some in their stomachs all of the time – it’s when it gets out of control that it can cause ulcers…..Giardia is a parasite that is frequently found in animals but obviously humans can get it, too

February 18, 2012 at 1:57 am
(15) Colleen McBride says:

I had Giardia a few years before I was diagnosed with fibromyalgia and cfs.I sufferedfor years after with irritable bowel syndrome. It’s amazing that many of the causes they are now coming up are things that happened to me. I pray that someday a cure will be found. In the meantime it’s wonderful that so much research is going on.

February 18, 2012 at 4:21 am
(16) Eva Wilson says:

I had a giardia infection back in the late 1990′s. I was treated for it by a GI doctor and I was also treated for the h pylori bug after that.
In early 2000′s I became extremely fatigued and in tremendous pain. I could barely function. It’s interesting that somehow a connection is made to the giardia parasite. It is possible that it could have been the icing on the cake to trigger the fibrom and fatigue and plunge it into it’s worst effects. Just another reason to take its toll on my immune system.

February 18, 2012 at 12:07 pm
(17) Jill G says:

In 1982 I was treated with Flagyl and was told I had an infection. No other information was given.
Frequently accused of being lazy, or hypochondriac since.
I’ve had Fibro symptoms since late childhood and teens.

February 22, 2012 at 12:43 pm
(18) Diane says:

I totally believe that this is one of the triggers. I had severe food poisoning in Mexico in 2007, I became progressively more ill over the past 4 years. I was dxed with Cryptosporidium in 2009 & treated but never got better. Now have ME/CFS we think.

October 8, 2013 at 3:53 pm
(19) Kim says:

Guess where 2/3 of your immunity comes from? Your intestines. Want to fix your problems- fix that……..

And sorry, ME/CFS is not inherited- but the same old bad habits certainly are.

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