Denise Grady, a science writer for The New York Times, recently explored the link between a recently discovered virus called XMRV and chronic fatigue syndrome, in “Is a Virus the Cause of Fatigue Syndrome?” On the Consults blog, scientists and doctors from the International Association for Chronic Fatigue Syndrome, a society of 500 biomedical and behavioral professionals, took readers’ questions on chronic fatigue syndrome.

Here, Dr. Nancy G. Klimas, who serves on the board of directors of the organization, answers questions on the recently discovered retrovirus and clinical care of chronic fatigue syndrome. Dr. Klimas is a director of the department of immunology of the University of Miami School of Medicine and director of research for clinical AIDS/H.I.V. research at the Miami Veterans Affairs Medical Center. Also read Fred Friedberg’s responses to behavior-related questions in “Behavioral Treatments for Chronic Fatigue Syndrome.”



Is Chronic Fatigue Syndrome Contagious?

Q.

I’ve had C.F.I.D.S. for 25 years. If it is a virus, is it contagious? How is it transmitted? Now I worry about passing it on to others. Thank you.

Nona

A.

Dr. Klimas responds:

In general, retroviruses are not spread by air or droplet but are transmitted sexually, vertically (mother to fetus) and by blood transfusion. From what we have learned about other retroviruses, it is clear that the amount of virus matters, and people with low amounts of circulating virus are not as infectious as people with high levels of virus in the blood. With XMRV, the retrovirus recently found in many patients with chronic fatigue syndrome, we do not have enough information to judge how infectious it might be.

Whenever the possibility of sexual transmission comes up, people worry that they are in some way responsible for infecting sexual partners. While this is possible, it is important to remember that many infections can come from exposures between great-great-grandparents and maintained for generations as latent infections, or as infections from early experiences of any sexual partner in a chain of partners. We know that it is very unusual for both partners to develop chronic fatigue syndrome, or C.F.S. And while mother-to-child C.F.S. can happen, it is unusual.

It is clear that there are a number of factors that increase the risk for C.F.S.: genetics, immune function, severity of inciting infection — to name a few. Just being exposed to, or even infected with, a virus does not mean that a person will become ill. We don’t even know if infection with the XMRV virus actually causes illness, or if it one of several associated reactivated viruses (like HHV-6, EBV and enterovirus).

It important not to take these new findings about the XMRV virus as anything more than an exciting new development. We need confirmatory studies, then studies to see if the virus is contributing to the cause of illness persistence and symptoms. The good news is that if XMRV is linked to C.F.S., there are many antiviral drugs that have already been safety tested in H.I.V. that may inhibit viral replication. So those studies could be designed very rapidly

Is There a Blood Test for the C.F.S. Virus?

Q.

Is there a specific test, blood or other, to determine whether a person is infected with the XMRV virus?

Beau Brincefield

A.

Dr. Klimas responds:

The test for XMRV that has been reported is currently used only in research settings. The research director of the Whittemore Peterson Institute, which was involved in the recent findings, was quoted as saying they were developing a commercial assay that they expected to be available “within weeks.” Several other commercial laboratories are also developing assays.

Some important points: First, antibody tests mean you have been exposed to a virus and do not tell you actually have an active infection. Second, a technique known as P.C.R. assays measures something called “viral load,” and the assay is designed to measure either active replicating virus or latent (inactive) virus. Either measure would be helpful with this new virus, but we don’t have access to them except in research settings.

Another way to see if you are infected is with viral cultures. The recent study published in Science used both cultures and P.C.R. assays.

Exercise and Chronic Fatigue Syndrome



Q.

I used to be very active and used to love playing sports. Then I was hit with some sort of infection. Eventually, after going to different doctors and health professionals, I was finally diagnosed with C.F.S.

I’m finding it easier to cope now. I try to have rest periods during the day. I would love to play sports again, but I just so feel so ill after I try and my muscles feel so sore. Have you any advice? Should I push through and go back to playing sports? I’m finding it tough enough as it is keeping up with college and the normal walking you have to do. I don’t want to drop out of college.

Pat

A.

Dr. Klimas responds:

Most C.F.S. patients do better if they break up their exercise into short segments, take brief rest periods and then try again. Certainly pushing through can cause “crashes” and relapses that can last days, even weeks. So I tell my patients the five-minute rule: five minutes of exercise, then five minutes lying flat, then five more minutes — increasing their exercise by five-minute increments.

If you can already tolerate more exercise than this, then try going that far, taking a break, then trying another round. Also, C.F.S. patients tolerate flexibility and resistance exercise (stretching and weight training) better than aerobics. Because C.F.S. patients are prone to blood pressure drops while exercising, they usually tolerate aerobic training best while in a flat position — swimming, recumbent bicycling, that sort of thing.

Can I Volunteer for a Study?

Q.

I’d like to second Post No. 25 and ask when and how one could volunteer to be part of a drug trial? Please help us.

Sally

A.

Dr. Klimas responds:

There are drug trials and other studies under way all around the United States and the globe looking at this illness and its possible treatments. Investigators at the Whittemore Peterson Institute and elsewhere are already planning antiviral trails based on this exciting research development. I would watch three Web sites in particular — the International Association for CFS/ME, the CFIDS Association of America, and the Whittemore Peterson Institute for Neuro-Immune Disease for more developments.

Was a C.F.S. Virus Discovered Years Ago?

Q.

Back in the early 1990s, Dr. Elaine DeFreitas at the Wistar Institute in Philadelphia discovered a novel human retrovirus (very closely related to HTLV 2, with Spuma-viruslike aspects) in C.F.I.D.S. patients. This was subsequently confirmed by two other prominent researchers (and a commercial laboratory).

Dr. DeFreitas was almost done sequencing its genes and published a meticulous paper in a top journal. Then the Centers for Disease Control and Prevention and the National Institutes of Health intentionally destroyed her reputation because it did not mesh with their vigorous assertions that C.F.I.D.S. was psychoneurosis. No one else has followed this up for fear that their career might likewise be destroyed. This was all detailed in the amazing book “Osler’s Web.”

Is this the same virus as the “novel” XMRV?

Justin Reilly

A.

Dr. Klimas responds:

Dr. DeFreitas was doing exciting work and should be congratulated for her early results suggesting retroviral infection in C.F.S. Since that time, technology has advanced in a dramatic way, giving investigators new tools to search for viruses that were yet to be identified in 1990-92, including the XMRV virus.

New antiviral drugs have also been developed that could potentially be effective in controlling this sort of infection. We also have a much stronger understanding of these drugs’ toxicity and safe use.

I congratulate the Whittemore Peterson Institute researchers for their diligent work. I am also very happy for Elaine today. I would also ask patients to be patient a little bit longer so that researchers can devise and perform the sort of clinical trials that will let us know if this virus is the linchpin in continued illness.

Links Between H.I.V. and XRMV?

Q.

I found the comparison to H.I.V. (all because it happens to be another retrovirus) to be alarmist, unnecessary and at worst, the kind of sensualist factoid reporting that’s more typical of a tabloid! From what I gather … the link between the two is weak and general at best.

What angers me is that the comparison to H.I.V. is completely out of context; there are many retroviruses that are not known to cause any pathologies at all – comparing it to the one that is most well known and feared is simplistic and quite simply wrong. We should not forget that retroviruses have been common through out human history, and while some do not cause disease at all, most are nowhere near as extreme as H.I.V.

To compare the virus to H.I.V. is to create undue alarm and suffering to people who are already dealing with a difficult disease. Not only is the comparison useless outside its context, it does nothing to provide useful information to the reader.

I ask that you think of the moral consequences of your sloppy comparison — the horror and anguish of those that might have thought that it might be as debilitating as H.I.V., as well as the dread of the thought of potentially passing it on to another person.

David

A.

Dr. Klimas responds:

You make a good point. This is one study, the results needs to be validated, then the next study will look at treatment options. And you are right, some retroviruses are seemingly benign, whereas others are pathogens.

But I hope you are not saying that C.F.S. patients are not as ill as H.I.V. patients. My H.I.V. patients for the most part are hale and hearty thanks to three decades of intense and excellent research and billions of dollars invested. Many of my C.F.S. patients, on the other hand, are terribly ill and unable to work or participate in the care of their families.

I split my clinical time between the two illnesses, and I can tell you if I had to choose between the two illnesses (in 2009) I would rather have H.I.V. But C.F.S., which impacts a million people in the United States alone, has had a small fraction of the research dollars directed towards it.

Despite these limitations, there has been considerable effort to understand the cause and develop effective treatments. The Whittemore Peterson Institute should be congratulated for its outstanding work, performed in a brand new center paid for with private donations, state money and N.I.H. collaboration. Creative research and creative financing!

Is Sleep a Factor in Chronic Fatigue Syndrome?

Q.

Do you think sleep could be a factor in C.F.S.? Have you heard of Xyrem being used to facilitate Stage 4, deep sleep? Most everyone with fibro and/or C.F.S. report of not being able to sleep deeply — to have restorative sleep. We are all anxiously waiting for help in this lifetime. So many years have been lost to these illnesses.

Abot Bensussen

A.

Dr. Klimas responds:

There is a clinical trial under way to study the effects of Xyrem, a medication used to treat sleep disorders like narcolepsy, in fibromyalgia. Certainly, getting restorative sleep is a good thing, and slow wave sleep is key to restorative sleep. A sleep expert can help with this part of treatment, but it is important to have a sleep study done before considering any sleep inducers.

In a study by my group, we found that about half of C.F.S. patients develop some level of sleep apnea over time, a treatable condition that could be worsened with some sleep medications.