Q and A with CDC SCIENTISTS

Through emails, CDC scientists Bill Switzer, lead investigator of the CDC XMRV study, and Dr. Steve Monroe, director of the CDC’s division of High Consequence Pathogens and Pathology, discussed the agency's XMRV study, published in Retrovirology July 1.  The study found no evidence of the retrovirus in the CDC's Chronic Fatigue Syndrome patients and controls.

I also asked Switzer and Monroe questions about the FDA/NIH XMRV study, which found the virus in CFS patients and had been accepted by Proceedings of the National Academy of Sciences only to be put on hold, which was reported June 30 in the Wall Street Journal.

A CDC press officer emailed Switzer’s and Monroe’s replies on Friday at 5:10 p.m.  Monroe had already left for the day; Switzer for a week’s vacation. Thus, there could be no timely follow-up.

CFS Central:

“My sources tell me that there were at least 20 XMRV samples confirmed to be positive from several other labs that were sent to you for the CDC study.  Did you test these samples, and what were your results when you tested the samples? Did you find XMRV or not?”

Bill Switzer MPH, lead investigator of the CDC XMRV study:
“As reported in Retrovirology, this study used and tested samples that were collected in CDC-sponsored studies of CFS, as well a set of healthy blood donors.  Continued efforts are underway to learn more about XMRV, including work with other HHS [Health and Human Services] agencies and non-governmental organizations to standardize testing methods across all XMRV studies.”

CFS Central:

“Why did the CDC request the FDA/NIH study be put on hold pending more research?”

Dr. Steve Monroe, director of CDC’s division of High Consequence Pathogens and Pathology:
“When CDC, FDA, and NIH learned that separate studies had been conducted with differing results, a collective decision was made to try and account for these differences.”

CFS Central:

“Why couldn’t both the CDC and the FDA/NIH papers be published and then the agencies do follow-up research to resolve the differences in your findings?”

Monroe:
“Timely discussion among researchers regarding the specifics of scientific studies is common and can help them more readily account for the direction of further research.  Future research will benefit from the knowledge gained from the Retrovirology study and other studies that have attempted to learn more about this novel retrovirus.”
 
CFS Central:

“Why didn’t the CDC try to culture XMRV?  (That’s what the Lombardi study did.)” [Published in Science in October 2009, that study found XMRV in 67 percent of 101 CFS patients.]

Switzer:

“It is unclear whether or not performing culture on all samples would have improved the ability to detect XMRV. The CDC Retrovirology study used the same PCR testing methods of a previously published study that found an association between XMRV and CFS. While CDC could not confirm an association between XMRV and CFS, the method utilized in the study provided the best means of detecting XMRV if it was present.”

CFS Central:

“Why didn’t the CDC use blood tubes intended for use with virus isolation as the Lombardi study did?”

Switzer:
“Many blood collection tubes with a variety of anticoagulants can be used for virus isolation. The archived specimens we used were collected with anticoagulants that are not known to interfere with either PCR testing or virus isolation.”

CFS Central:

“According to your paper, the CDC used the ‘revised Fukuda’ AKA Empirical definition of CFS…. The CDC study cohort, as defined by the Empirical definition, includes many people who are simply depressed and tired but do not have Chronic Fatigue Syndrome. How can this CDC cohort be valid if it includes people who are just tired and depressed?”

Monroe:
“All subjects in the study met the 1994 International Research Case Definition for CFS. One aspect of the definition is its ability to distinguish between subjects who may suffer from CFS symptoms, such as tiredness or depression, but do not have CFS.  CDC used samples from CFS subjects who fully met the 1994 case definition and healthy controls that were collected from two previous population-based studies in Wichita, Kansas and metropolitan, urban and rural populations in Georgia. In addition, CFS patients from the CDC Health Care Provider-based Registry of Unexplained Fatiguing Illnesses and CFS were included.

“Thus, CDC used population-based and clinic referral samples. This enabled us to examine sudden onset cases and those that develop gradually. The use of both types of samples in this study helped us to more precisely examine whether or not infection, such as through XMRV, might have played a role in the onset of symptoms.”

***

Having had none of my questions answered by the CDC, I turned to other sources.

Coming up:  THE FDA/NIH XMRV PAPER—and ME/CFS PATIENTS—IN LIMBO.  Plus, one patient’s solution:  A united demonstration of solidarity at blood banks in every city, in every country, and on every continent to inform the public that Health and Human Services is withholding the publication of the FDA/NIH XMRV study and that the newly discovered retrovirus may be contaminating the blood supply and infecting millions of people.


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