How Many Of The ME/CFS Patients Are Infected With XMRV?

by Johan on November 15, 2009

The article, Detection of an Infectious Retrovirus, XMRV, in Blood Cells of Patients with Chronic Fatigue Syndrome, published in Science Express on October 8, 2009 send a shockwave through the ME/CFS-community. But how many of the ME/CFS patient samples tested positive for the XMRV retrovirus? Was it 67%, 95%, 98%, or 100%?

67% – 3.7%

At the time of writing this post, the above mentioned article was the only publication in a respected scientific magazine on the link between the retrovirus XMRV and ME/CFS. The initial research showed that 67% of the CFS patient samples tested positive for XMRV, compared to only 3.7% of samples of healthy individuals. The original article doesn’t reveal the selection criteria for the patients and it only mentions Chronic Fatigue Syndrome (CFS). The website of the Whittemore Peterson Institute also mentions Myalgic Encephalomyelitis (ME), Atypical Multiple Sclerosis (MS), Fibromyalgia (FM), and Gulf War Syndrome.


A more recent study at the Whittemore Peterson Institute found that more than 95% of the over 200 patients with ME/CFS, FM and Atypical MS are infected with XMRV. They haven’t published any details on this new research yet, nor do they mention the percentage of healthy people infected with XMRV according to this new test.
When I read this, my first reaction was disbelief. Can a heterogeneous disease like ME/CFS really be linked to one retroviral infection? My second thought was that they must have targeted a specifically selected group of ME/CFS patients and not just some randomly picked individuals. If this is the case, what where the selection criteria? Were all the blood and tissue samples from the repository of Dr. Daniel Peterson? From the Lake Tahoe outbreak? Dr. Judy Mikovits from WPI already told that she used Peterson’s repository for finding the retrovirus.

98% – 6-7%

I have found these numbers in articles and on blogs, 98% of CFS patients and 6-7% of healthy people infected with XMRV, but I couldn’t link this to a scientific article or to the Whittemore Peterson Institute. Probably a journalist or blogger who made a typo which got copied by others, at least for the 6-7% infection rate of healthy people. The 98% figure did appear in an article on the website of the New York Times on October 12, 2009: ‘Is a Virus the Cause of Fatigue Syndrome?‘ by Denise Grady. She already had the name of the disease wrong for starters.


In an opinion article in the New York Times, Hillary Johnson writes about an interview with Dr. Judy Mikovits.

What she found was live, or replicating, XMRV in both frozen and fresh blood and plasma, as well as saliva. She has found the virus in samples going back to 1984 and in nearly all the patients who developed cancer. She expects the positivity rate will be close to 100 percent in the disease.

Are we still discussing ME/CFS in general here, or the samples from Daniel Peterson’s repository and the Lake Tahoe outbreak? Did they focus on all Dan Peterson’s ME/CFS patients or just on those who were suffering from rare lymphomas and leukemias? Was altered RNase L activity a selection criterium? Is research based on a ME/CFS outbreak also valid for individual ME/CFS sufferers?
Anyway stating that the positivity rate will be close 100% at this stage of research is pure speculation and outside the realm of science.


It is an exciting time and as other institutes and researchers rise to challenge and I hope we can expect some answers to these questions in the very near future. Whether the findings of WPI get confirmed, or not. This may sound harsh, but at this moment all articles on cause, treatment, cure, and vindication (finally getting rid of the between-the-ears gang) are a hype.
I don’t care about political correctness. At this moment it is neither intellectually, nor scientifically, nor medically correct to state that XMRV causes ME/CFS. They might have found a possible link. That is fine by me. I can live with that … for now. Studies in Germany and Ireland were unable to link XMRV to prostate cancers. Know that it was the discovery of XMRV in a subset of prostate cancer patients that prompted WPI to test whether the retrovirus might be associated with CFS.

I am fully aware that this article may become outdated very soon.


  • ‘Xplained’ by Suzanne D. Vernon, PhD, Scientific Director, The CFIDS Association of America, link.
  • Whittemore Peterson Institute for Neuro Immune Disease, link.
  • ‘Is a Virus the Cause of Fatigue Syndrome? ‘ by Denise Grady, New York Times (October 12, 2009), link.
  • ‘A Case of Chronic Denial’ by Hillary Johnson, New York Times (October 20, 2009), link.
  • ‘Detection of an Infectious Retrovirus, XMRV, in Blood Cells of Patients with Chronic Fatigue Syndrome’, Science Express (abstract), link.
  • ‘Detection of an Infectious Retrovirus, XMRV, in Blood Cells of Patients with Chronic Fatigue Syndrome’ and more news, Whittemore Peterson Institute (full article), link.
  • ‘The Fog of War’ by Hillary Johnson, Osler’s Web, link.
  • ‘XMRV not detected in German prostate cancer’ by Vincent Racaniello, Virology blog, link.
May you live in interesting times
Chinese curse

{ 7 comments… read them below or add one }

Dominique February 8, 2010 at 3:33 am

I just put two and two together and realized we were friends on twitter and I had been reading your blog for a while! LOL

I agree with you here, 100%. I actually do not believe this will be the cause. We are living in bodies that are not functioning properly so the fact that viruses are being found make sense to me.

I also wonder, if it is deemed the cause, why the vast array of symptoms within the CFIDS/ME community? Shouldn’t we all have pretty much the same symptom-ology and severity?


oerganix March 22, 2010 at 5:02 pm

Dominique, most of the doctors who treat CFS/ME have said for decades that it is probably a virus or retrovirus that is the cause. Dr Bell, who has been treating CFS for decades, says “It fits”.

Just think of all the symptoms one feels when they have the flu. All caused by one virus.


Dominique March 22, 2010 at 6:11 pm

I have read about other possibilities that could cause these symptoms. I personally believe that it may be something other then just a virus or that virus’s are the causal link.

I Like Dr. Bell and I understand that he feels a virus fits. Maybe it will be the causal link but I am willing to consider other things as well.


oerganix March 22, 2010 at 9:52 pm

Sure, I think we’ll all be open to considering other causes until one, or more, is actually found. I was just responding to your idea that we should all have the same symptoms and severity. That doesn’t happen in any other illness, so why expect it of CFS/ME.

As for some of the statements in this blog, I realize they’re just repeated rumors at this point, but I would like to point out that the original cohort studied by WPI did not comprise “an outbreak”…anywhere. The politically motivated European researchers keep saying that, although they, too, know it isn’t true. They desperately want to disprove any physical cause so they can keep up the mythology that ME is a mental disorder.

Dr Mikovits stated at a public presentation that when they unblinded their cohort, to notify patients of their XMRV status, she found that patients came from clinics across the US and of those patients, some came from UK, Ireland, Germany and Australia, as well as many US States.

Where samples from Dr Peterson’s clinic came into play was at the very beginning, when they were trying to figure out what to look for. Since he has been collecting samples from the early 1980’s to the present and his patients come from all over the world, this can hardly be characterized as coming from an “outbreak”.

Anyway, Johan, I’m vicariously enjoying your experience with Dr deMeirleir; I think you were quite right not to spend the money on the XMRV test, since it’s still being refined, is mainly for research and no one would know what to do about it yet anyway. You may already know this, but WPI and a lab in Europe are doing a blinded study of XMRV and normal samples, to see if they come up with similar results. Patients in UK are currently being contacted for blood draws. UK patients who got together several months ago and sent their blood to VIPdx for testing have about 50% positives so far.


Johan March 24, 2010 at 8:12 pm

At oerganix & Dominique

Question: Is ME/CFS a single disease with a single cause? Or is it a collection of diseases and causes with similar symptoms? Think Gulf War Syndrome, FM, PVFS, …
I do not have the answer. To me ME or CFS means that you have an as yet undefined disease.

Flu-like symptoms can be caused by bacteria as well; take Lyme-disease for example. Fatigue and cognitive impairment caused by a very active immune system (linked to cytokines) can not only be caused by viral and bacterial infections, but also by cancer.

The fight between the biomedical and psychological school over a disease isn’t without precedent: autism, multiple sclerosis, Alzheimer, AIDS, … all were considered at some point in time to originate between the ears. Psychiatrists and psychologists don’t like losing market share. Now that there is a possible link with a retrovirus they are putting public health at risk (bloodbanks) with their power games, but then again in the UK ME/CFS patients are already not allowed to donate blood.

I think doctors should answer 4 questions when confronted with ME/CFS patient, and answer them separately:
1. What are the symptoms and how can I verify/measure them?
Think out of the box. Standard medical test are inadequate.
2. What is the cause?
“I don’t know” is a more honest answer than “It must be in your head”.
3. Is there a treatment?
If no cause is found, if the disease can’t be named,
can at least (some) of the symptoms be treated?
4. Is this person fit work?

I have the impression that some doctors reason like this: (standard) tests come up negative, so there is nothing wrong, there is no disease, so this patient can go to work. This reasoning is lacking in scientific rigor and intellectual honesty. I think the questions should be answered separately.

I have read that a Swedish study funded by a ME organization in the UK hopes to publish results before the Summer. In Belgium Red Labs will start testing for XMRV in a few weeks time. This means that European samples will no longer have to be send to the USA. Interesting times indeed.

Thanks for commenting


Dominique March 24, 2010 at 10:06 pm

Johan – Question?

It’s been 15+ years since I have been diagnosed. Do the doctors still rule everything out before they make the diagnosis of CFIDS? When I got ill, everything was ruled out. It was the illness of exclusion. Is that still the procedure?

I am concerned that the research is becoming challenging and cumbersome because I can now have CFDIS and other illnesses so how does a researcher (or doctor for that matter) determined which illness is the causal link?

I think you were alluding to that, unless I misunderstood.

Anyway, I agree. Doctors should have a standard means of making the diagnosis and determination for disability. I had to go before a Judge and ‘prove’ my case in order to be considered 100% disabled. A doctor just couldn’t seem to do that for me.


Johan March 27, 2010 at 11:47 am

It has been 8 years for me. At the time it was and as far as I can tell now it still is a diagnosis of exclusion. I wouldn’t dare to say that they ruled out everything, the most obvious things probably and then off you go to the CFS clinic for CBT. I didn’t get as much tests as I wanted to, but as you probably know I am getting tested at a biomedical CFS clinic now and hopefully I will get some answers in May.

In my opinion if you have several illnesses they should be treated if possible. The question as to the cause can be answered some other time. That was what I was trying to say. Even if doctors do not know the cause, this shouldn’t stop them from starting to treat illnesses and symptoms. Even without knowing the cause they should be able to asses the impact on your life and the ability to go to work or care for yourself.

I am officially on disability, for now. How long this will last I have no idea. Several CFS patients I know off lost disability and are now unemployed, but considered unemployable. A situation that can change at any time. So they live in constant uncertainty. Some had to lawyer up and go to court.


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