After Justin pointed out that the CDC website on the XMRV paper tries to pass off the empirical definition as the Fukuda Criteria, I wrote this letter to the CDC. I pasted it into the contact form on this page, http://www.cdc.gov/contact/index3.htm, and also sent it as an email to Dr. Frieden (CDC Director) and Dr. Unger (acting chief of the Chronic Viral Diseases Branch, which houses the CFS Research Program). Their addresses are firstname.lastname@example.org and email@example.com, respectively. I purposely made this letter straightforward and non-accusatory. If they don’t amend the webpage, I’ll raise the rhetoric and forward the letter with a sterner preface to higher-ups at DHHS. Feel free to copy. Don't forget to sign your name and add your location, if you wish. *** Dear Centers for Disease Control: I’m writing to point out a factual error on your webpage entitled “Updates: XMRV”, located at http://www.cdc.gov/ncidod/dhqp/bp_xmrv_overview.html. The error concerns which case definition was used to select CFS patients for a recent CDC study on XMRV by Switzer et al. The webpage reads, “Patients from both groups had CFS that met the criteria of the 1994 International CFS Research Case Definition, which was established to help distinguish CFS from other illnesses that cause fatigue.” Several paragraphs down, the page continues, “The CDC-led team tested specimens collected from previous population-based studies in Kansas and in Georgia and from physician referrals in Georgia. All CFS patients received a clinical assessment and had a diagnosis that met the criteria of the 1994 International CFS Research Case Definition.” Both these statements imply that the patients met criteria for the case definition described in 1994 by Fukuda et al. (1) and commonly known as the Fukuda Criteria. However, the Switzer paper, which was peer-reviewed and published, makes clear that your patients were selected by different criteria. The paper reads, “Archived blood specimens were tested from persons with CFS defined by the revised 1994 CDC case definition and matched healthy controls from Wichita, Kansas and metropolitan, urban, and rural Georgia populations.” This “revised 1994 CDC case definition” was described in 2005 in a paper by Reeves et al. (2) and is commonly known as the empirical definition or Reeves Criteria. The difference between the empirical definition, which was used by Switzer et al., and the Fukuda Criteria, which your webpage implies were used, is significant. Work by Reyes et al. (3) in 2003 found 240 people with CFS per 100,000 in Wichita, Kansas. In 2007, Reeves et al. (4), using the empirical definition, found 2,540 people with CFS per 100,000 in Georgia. Markedly broader than its predecessor, the empirical definition diagnosed more than ten times as many people with CFS. The paper by Switzer et al. also notes that the CFS patients under study were administered “standardized questionnaires” to assess fatigue, functional impairment, and symptoms. The use of these questionnaires is another tip-off that the case definition employed by the study is the empirical definition, not the Fukuda Criteria. The error on your webpage can easily be corrected by inserting the word “revised” before the phrase “1994 International CFS Research Case Definition”, which appears twice. Doing so will reconcile the page with your published study. Thank you for your time. I look forward to viewing the amended page. Sincerely, References: (1) Fukuda K, Straus SE, Hickie I, Sharpe MC, Dobbins JG, Komaroff A. The chronic fatigue syndrome - a comprehensive approach to its definition and study. Annals of Internal Medicine 1994, 121:953-959. (2) Reeves WC, Wagner D, Nisenbaum R, Jones JF, Gurbaxani B, Solomon L, Papanicolaou DA, Unger ER, Vernon SD, Heim C. Chronic fatigue syndrome—a clinically empirical approach to its definition and study. BMC Medicine 2005, 3:19. (3) Reyes, M., Nisenbaum, R., Hoaglin, D.C., Unger, E.R., Emmons, C., Randall, B., Stewart, G., Abbey, S., Jones, J. F., Gantz, N., Minden, S., & Reeves, W.C. Prevalence and incidence of chronic fatigue syndrome in Wichita, Kansas. Archives of Internal Medicine 2003, 163, 1530-1536. (4) Reeves, W.C., Jones, J.J., Maloney, E., Heim, C., Hoaglin, D.C., Boneva, R., Morrissey, M., & Devlin, R. New study on the prevalence of CFS in metro, urban and rural Georgia populations. Population Health Metrics 2007, 5:5.