Treatment of chronic fatigue syndrome with antibiotics: pilot study assessing the involvement of Coxiella burnetii infection

Oral Minocycline Therapy Improves Symptoms of Myalgic Encephalomyelitis, Especially in the Initial Disease Stage

Objective Central nervous system dysfunction associated with myalgic encephalomyelitis (ME) has been suggested to be the main cause of chronic fatigue syndrome. In animal models of chronic fatigue, minocycline was reported to act as a suppressor of neural inflammation. Minocycline may thus exert favorable therapeutic effects in patients with ME. Methods Oral minocycline (100 mg×2 on the first day, followed by 100 mg/day for 41 days) was administered to 100 patients with ME. The performance status score (0-9), orthostatic intolerance during the 10-min standing test, neurologic disequilibrium, and neuropathic pain were compared before and after treatment. Results After therapy completion, favorable effects were observed with a decrease in the performance status score of ≥2 points in 27 patients (27%). Before treatment, 6 of the 27 patients had orthostatic intolerance with an inability to complete the 10-min standing test; after treatment, this symptom resolved in 4 and improved in 2 patients. In addition, after treatment, postural orthostatic tachycardia resolved in five of eight patients, disequilibrium resolved in five of eight patients, and fibromyalgia or neuropathic pain was attenuated in four of five patients. The favorable effects appeared dependent on a shorter disease duration, primarily for a duration of less than three years and most frequently within six months of the disease onset. However, acute adverse effects with nausea and/or dizziness caused 38 patients (38%) to discontinue treatment in the first few days. Conclusion Oral minocycline therapy may be an effective treatment option for patients with ME, especially in the initial stage of the disease.

Neurotransmitter System-Targeting Drugs Antagonize Growth of the Q Fever Agent, Coxiella burnetii, in Human Cells

Coxiella burnetii is a highly infectious, intracellular, Gram-negative bacterial pathogen that causes human Q fever, an acute flu-like illness that can progress to chronic endocarditis. C. burnetii is transmitted to humans via aerosols and has long been considered a potential biological warfare agent. Although antibiotics, such as doxycycline, effectively treat acute Q fever, a recently identified antibiotic-resistant strain demonstrates the ability of C. burnetii to resist traditional antimicrobials, and chronic disease is extremely difficult to treat with current options. These findings highlight the need for new Q fever therapeutics, and repurposed drugs that target eukaryotic functions to prevent bacterial replication are of increasing interest in infectious disease. To identify this class of anti-C. burnetii therapeutics, we screened a library of 727 FDA-approved or late-stage clinical trial compounds using a human macrophage-like cell model of infection. Eighty-eight compounds inhibited bacterial replication, including known antibiotics, antipsychotic or antidepressant treatments, antihistamines, and several additional compounds used to treat a variety of conditions. The majority of identified anti-C. burnetii compounds target host neurotransmitter system components. Serotoninergic, dopaminergic, and adrenergic components are among the most highly represented targets and potentially regulate macrophage activation, cytokine production, and autophagy. Overall, our screen identified multiple host-directed compounds that can be pursued for potential use as anti-C. burnetii drugs.

IMPORTANCECoxiella burnetii causes the debilitating disease Q fever in humans. This infection is difficult to treat with current antibiotics and can progress to long-term, potentially fatal infection in immunocompromised individuals or when treatment is delayed. Here, we identified many new potential treatment options in the form of drugs that are either FDA approved or have been used in late-stage clinical trials and target human neurotransmitter systems. These compounds are poised for future characterization as nontraditional anti-C. burnetii therapies.

Altered Structural Brain Networks Related to Adrenergic/Muscarinic Receptor Autoantibodies in Chronic Fatigue Syndrome

BACKGROUND AND PURPOSE

Recent studies suggest that the autoantibodies against adrenergic/muscarinic receptors might be one of the causes and potential markers of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). The purpose of this study was to investigate the structural network changes related to autoantibody titers against adrenergic/muscarinic receptors in ME/CFS by performing a single-subject gray matter similarity-based structural network analysis.

METHODS

We prospectively examined 89 consecutive right-handed ME/CFS patients who underwent both brain MRI including 3D T1-wighted images and a blood analysis of autoantibodies titers against β1 adrenergic receptor (β1 AdR-Ab), β2 AdR-Ab, M3 acetylcholine receptor (M3 AchR-Ab), and M4 AchR-Ab. Single-subject gray matter similarity-based structural networks were extracted from segmented gray matter images for each patient. We calculated local network properties (betweenness centrality, clustering coefficient, and characteristic path length) and global network properties (normalized path length λ, normalized clustering coefficient γ, and small-world network value δ). We investigated the correlations between the autoantibody titers and regional gray matter/white matter volumes, the local network properties, and the global network properties.

RESULTS

Betweenness centrality showed a significant positive correlation with β1-AdR-Ab in the right dorsolateral prefrontal cortex. The characteristic path length showed a significant negative correlation with β2-AdR-Ab in the right precentral gyrus. There were no significant correlations between the antibody titers and the regional gray matter/white matter volumes, and the global network properties.

CONCLUSIONS

Our findings suggest that β1 AdR-Ab and β2 AdR-Ab are potential markers of ME/CFS.

Long-term effect of cognitive behavioural therapy and doxycycline treatment for patients with Q fever fatigue syndrome: One-year follow-up of the Qure study

BACKGROUND

Previously, we reported a randomized placebo-controlled trial, the Qure study, showing that cognitive behavioural therapy (CBT), and not doxycycline, was significantly more effective than placebo in reducing fatigue severity in Q fever fatigue syndrome (QFS) patients. This follow-up study evaluates the long-term effect of these treatment regimens, 1 year after completion of the original trial.

METHODS

All patients who completed the Qure study, CBT (n = 50), doxycycline (n = 52), and placebo (n = 52), were included in this follow-up study. Between twelve and fifteen months after end of treatment (EOT), patients filled out web-based questionnaires including the main outcome measure fatigue severity, assessed with the Checklist Individual Strength (CIS), subscale fatigue severity.

RESULTS

Fatigue severity in the CBT, but not doxycycline or placebo, group was significantly increased at follow-up compared to EOT (respective means 39.5 [95% CI, 36.2-42.9] and 31.3 [95% CI, 27.5-35.1], mean difference 8.2 [95% CI, 4.9-11.6]; P < .001). Fatigue severity scores of CBT (adjusted mean 39.8 [95% CI, 36.1-43.4]) and doxycycline (adjusted mean 41.0 [95% CI, 37.5-44.6]) groups did not significantly differ from the placebo group (adjusted mean 37.1 [95% CI, 33.6-40.7]; P = .92 and P = .38, respectively).

CONCLUSION

The beneficial effect of CBT on fatigue severity at EOT was not maintained 1 year thereafter. Due to its initial beneficial effect and side effects of long-term doxycycline use, we still recommend CBT as treatment for QFS. We suggest further investigation on tailoring CBT more to QFS, possibly followed by booster sessions.

Effectiveness of Long-term Doxycycline Treatment and Cognitive-Behavioral Therapy on Fatigue Severity in Patients with Q Fever Fatigue Syndrome (Qure Study): A Randomized Controlled Trial

Background

Approximately 20% of patients with acute Q fever will develop chronic fatigue, referred to as Q fever fatigue syndrome (QFS). The objective of this randomized controlled clinical trial was to assess the efficacy of either long-term treatment with doxycycline or cognitive-behavioral therapy (CBT) in reducing fatigue severity in patients with QFS.

Methods

Adult patients were included who met the QFS criteria according to the Dutch guideline: a new onset of severe fatigue lasting ≥6 months with significant disabilities, related to an acute Q fever infection, without other somatic or psychiatric comorbidity explaining the fatigue. Using block randomization, patients were randomized between oral study medication and CBT (2:1) for 24 weeks. Second, a double-blind randomization between doxycycline (200 mg/day, once daily) and placebo was performed in the medication group. Primary outcome was fatigue severity at end of treatment (EOT; week 26), assessed with the Checklist Individual Strength subscale Fatigue Severity.

Results

Of 155 patients randomized, 154 were included in the intention-to-treat analysis (doxycycline, 52; placebo, 52; CBT, 50). At EOT, fatigue severity was similar between doxycycline (40.8 [95% confidence interval {CI}, 37.3-44.3]) and placebo (37.8 [95% CI, 34.3-41.2]; difference, doxycycline vs placebo, -3.0 [97.5% CI, -8.7 to 2.6]; P = .45). Fatigue severity was significantly lower after CBT (31.6 [95% CI, 28.0-35.1]) than after placebo (difference, CBT vs placebo, 6.2 [97.5% CI, .5-11.9]; P = .03).

Conclusions

CBT is effective in reducing fatigue severity in QFS patients. Long-term treatment with doxycycline does not reduce fatigue severity in QFS patients compared to placebo.

Clinical Trials Registration

NCT01318356.

From Q Fever to Coxiella burnetii Infection: a Paradigm Change

Coxiella burnetii is the agent of Q fever, or "query fever," a zoonosis first described in Australia in 1937. Since this first description, knowledge about this pathogen and its associated infections has increased dramatically. We review here all the progress made over the last 20 years on this topic. C. burnetii is classically a strict intracellular, Gram-negative bacterium. However, a major step in the characterization of this pathogen was achieved by the establishment of its axenic culture. C. burnetii infects a wide range of animals, from arthropods to humans. The genetic determinants of virulence are now better known, thanks to the achievement of determining the genome sequences of several strains of this species and comparative genomic analyses. Q fever can be found worldwide, but the epidemiological features of this disease vary according to the geographic area considered, including situations where it is endemic or hyperendemic, and the occurrence of large epidemic outbreaks. In recent years, a major breakthrough in the understanding of the natural history of human infection with C. burnetii was the breaking of the old dichotomy between "acute" and "chronic" Q fever. The clinical presentation of C. burnetii infection depends on both the virulence of the infecting C. burnetii strain and specific risks factors in the infected patient. Moreover, no persistent infection can exist without a focus of infection. This paradigm change should allow better diagnosis and management of primary infection and long-term complications in patients with C. burnetii infection.

Increase in the Regional Cerebral Blood Flow following Waon Therapy in Patients with Chronic Fatigue Syndrome: A Pilot Study

Objective Chronic fatigue syndrome (CFS) is a complex disorder, with no consensus on therapeutic options. However, Waon therapy has been reported to be an effective treatment. The purpose of this study was to evaluate changes in the cerebral blood flow (CBF) before and after Waon therapy in CFS patients and to investigate the correlation between such changes and the therapeutic efficacy of Waon therapy. Methods Eleven patients (2 men and 9 women, mean age 27 years old) diagnosed with CFS participated in the study. The disease duration was 8-129 months, and the performance status was 5-8 (on a scale of 0-9). All patients underwent CBF scintigraphy using brain single-photon emission computed tomography (SPECT) with technetium-99m ethyl cysteinate dimer (^99mTc-ECD) before and after Waon therapy. CBF changes after Waon therapy were evaluated using a statistical analysis of imaging data, which was performed with a statistical parametric mapping software program (SPM5). Results Waon therapy reduced symptoms in all 11 patients. We also observed an increase in the CBF within the prefrontal region, orbitofrontal region, and right temporal lobe. These results indicated that an improvement in clinical symptoms was linked to an increase in the CBF. Conclusion The results indicated abnormalities of the cerebral function in the prefrontal region, orbitofrontal region, and right temporal lobe in CFS patients and that Waon therapy improved the cerebral function and symptoms in CFS patients by increasing the regional CBF. To our knowledge, this is the first report to clarify the CBF changes in CFS patients before and after Waon therapy.

The natural history of acute Q fever: a prospective Australian cohort

BACKGROUND

A detailed description of the natural history of acute Q fever, caused by infection with Coxiella burnetii, AIM: : To significantly increase understanding of the illness.

DESIGN

Subjects with provisional acute Q fever (n = 115) were recruited from primary care in rural Australia, and followed prospectively by interview and blood collection including for serological confirmation. A nested series of subjects with prolonged illness (cases), and those without (controls), were investigated in detail.

METHODS

Total phase I and phase II anti-C. burnetii antibodies were detected by complement fixation test; and IgG, IgM and IgA phase I and phase II titres by immunofluorescence. Flow cytometric analysis was conducted to enumerate circulating T cells subsets, B cells, monocytes and natural killer cells.

RESULTS

Serological testing confirmed acute Q fever in 73 subjects (63%). The acute illness featured fever, headache, sweats, fatigue and anorexia; and varied widely in severity, causing an average of 8 days in bed and 15 days out of work or other role in the first month of illness. The illness course varied from 2 days to greater than a year. No cases of chronic, localized Q fever infection, such as endocarditis, were identified. Neither severe nor prolonged illness were associated with persistence of C. burnetii DNA, altered patterns of C. burnetii-specific IgG, IgM or IgA antibody production, or altered leucocyte subsets.

CONCLUSIONS

The severity of acute Q fever alone predicted prolonged duration. Further studies are warranted to better understand the pathophysiology of prolonged illness after acute Q fever.

Fatigue following Acute Q-Fever: A Systematic Literature Review

BACKGROUND

Long-term fatigue with detrimental effects on daily functioning often occurs following acute Q-fever. Following the 2007-2010 Q-fever outbreak in the Netherlands with over 4000 notified cases, the emphasis on long-term consequences of Q-fever increased. The aim of this study was to provide an overview of all relevant available literature, and to identify knowledge gaps regarding the definition, diagnosis, background, description, aetiology, prevention, therapy, and prognosis, of fatigue following acute Q-fever.

DESIGN

A systematic review was conducted through searching Pubmed, Embase, and PsycInfo for relevant literature up to 26th May 2015. References of included articles were hand searched for additional documents, and included articles were quality assessed.

RESULTS

Fifty-seven articles were included and four documents classified as grey literature. The quality of most studies was low. The studies suggest that although most patients recover from fatigue within 6-12 months after acute Q-fever, approximately 20% remain chronically fatigued. Several names are used indicating fatigue following acute Q-fever, of which Q-fever fatigue syndrome (QFS) is most customary. Although QFS is described to occur frequently in many countries, a uniform definition is lacking. The studies report major health and work-related consequences, and is frequently accompanied by nonspecific complaints. There is no consensus with regard to aetiology, prevention, treatment, and prognosis.

CONCLUSIONS

Long-term fatigue following acute Q-fever, generally referred to as QFS, has major health-related consequences. However, information on aetiology, prevention, treatment, and prognosis of QFS is underrepresented in the international literature. In order to facilitate comparison of findings, and as platform for future studies, a uniform definition and diagnostic work-up and uniform measurement tools for QFS are proposed.

Sleep quality and the treatment of intestinal microbiota imbalance in Chronic Fatigue Syndrome: A pilot study

Chronic Fatigue Syndrome (CFS) is a multisystem illness, which may be associated with imbalances in gut microbiota. This study builds on recent evidence that sleep may be influenced by gut microbiota, by assessing whether changes to microbiota in a clinical population known to have both poor sleep and high rates of colonization with gram-positive faecal Streptococcus, can improve sleep. Twenty-one CFS participants completed a 22- day open label trial. Faecal microbiota analysis was performed at baseline and at the end of the trial. Participants were administered erythromycin 400 mg b.d. for 6 days. Actigraphy and questionnaires were used to monitor sleep, symptoms and mood. Changes in patients who showed a clinically significant change in faecal Streptococcus after treatment (responders; defined as post-therapy distribution<6%) were compared to participants who did not respond to treatment. In the seven responders, there was a significant increase in actigraphic total sleep time (p=0.028) from baseline to follow up, compared with non-responders. Improved vigour scores were associated with a lower Streptococcus count (ρ=-0.90, p=0.037). For both the responders and the whole group, poorer mood was associated with higher Lactobacillus. Short term antibiotic treatment appears to be insufficient to effect sustainable changes in the gut ecosystem in most CFS participants. Some improvement in objective sleep parameters and mood were found in participants with reduced levels of gram-positive gut microbiota after antibiotic treatment, which is encouraging. Further study of possible links between gut microorganisms and sleep and mood disturbances is warranted.

Effects of Waon therapy on chronic fatigue syndrome: a pilot study

OBJECTIVE

Chronic fatigue syndrome (CFS) is a disabling condition of unknown etiology, and no definitive therapy has been identified to date. We developed Waon therapy, a form of thermal therapy using a far-infrared dry sauna, and in this study herein examined its feasibility and safety in patients with CFS.

METHODS

Ten consecutive inpatients with CFS stayed in a 60°C sauna for 15 minutes and then rested on a bed under a blanket for an additional 30 minutes outside the sauna room. The treatments were performed once a day, five days a week for four weeks. Perceived fatigue, the primary outcome measure, was evaluated using a numerical rating scale before, during (two weeks after the commencement of therapy) and after therapy. The pain level, evaluated using a numerical rating scale, mood, assessed using the Profile of Mood States questionnaire, and performance status, assessed using a scale developed for CFS patients were also examined before and after therapy.

RESULTS

Perceived fatigue significantly decreased after therapy, although no significant reductions were observed during therapy. In addition, a negative mood, including anxiety, depression and fatigue, and the performance status significantly improved after therapy. However, the levels of pain and vigor did not change significantly. No patients reported any adverse effects during the therapy.

CONCLUSION

These findings suggest that Waon therapy may be a useful and safe treatment for CFS.

The Qure study: Q fever fatigue syndrome--response to treatment; a randomized placebo-controlled trial

BACKGROUND

Q fever is a zoonosis that is present in many countries. Q fever fatigue syndrome (QFS) is one of the most frequent sequelae after an acute Q fever infection. QFS is characterized by persistent fatigue following an acute Q fever infection, leading to substantial morbidity and a high socio-economic burden. The occurrence of QFS is well-documented, and has been described in many countries over the past decades. However, a treatment with proven efficacy is not available. Only a few uncontrolled studies have tested the efficacy of treatment with antibiotics on QFS. These studies suggest a positive effect of long-term treatment with a tetracycline on performance state; however, no randomized controlled trials have been performed. Cognitive behavioral therapy (CBT) has been proven to be an effective treatment modality for chronic fatigue in other diseases, but has not yet been tested in QFS. Therefore, we designed a trial to assess the efficacy of long-term treatment with the tetracycline doxycycline and CBT in patients with QFS.

METHODS/DESIGN

A randomized placebo-controlled trial will be conducted. One-hundred-eighty adult patients diagnosed with QFS will be recruited and randomized between one of three groups: CBT, long-term doxycycline or placebo. First, participants will be randomized between CBT and medication (ratio 1:2). A second double-blinded randomization between doxycycline and placebo (ratio 1:1) will be performed in the medication condition. Each group will be treated for six months. Outcome measures will be assessed at baseline and post intervention. The primary outcome measure is fatigue severity. Secondary outcome measures are functional impairment, level of psychological distress, and Coxiella burnetii PCR and serology.

DISCUSSION

The Qure study is the first randomized placebo-controlled trial, which evaluates the efficacy of long-term doxycycline and of cognitive behavioral therapy in patients with QFS. The results of this study will provide knowledge about evidence-based treatment options for adult patients with QFS.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01318356, and Netherlands Trial Register: NTR2797.

Are fatigue symptoms and chronic fatigue syndrome following Q fever infection related to psychosocial variables?

OBJECTIVE

Fatigue is known as one of the most common long-term sequelae of Q fever infections. The study aimed to determine the prevalence of fatigue symptoms, chronic fatigue, and chronic fatigue syndrome (CFS) in a sample of patients who were exposed to Q fever (Coxiella burnetii) infection compared to controls, and to contrast Q fever patients with and without fatigue symptoms related to somatoform symptoms, hypochondriacal worries and beliefs, psychosocial complaints, and social support.

METHODS

Cross-sectional study of 84 Q fever exposed patients from a specific region in Jena (Germany) and 85 matched controls using standardized questionnaires (MFI, SF-12, CDC-SI, SOMS, Whiteley Index, OQ-45 and F-Sozu). Diagnostic interviews were performed to validate questionnaire results in a smaller subsample.

RESULTS

Patients who were exposed to a Q fever infection in the past indicated more fatigue symptoms and chronic fatigue than controls (54.8 vs. 20%, 32.1 vs. 4.7%) but did not show more criteria for a CFS (1 patient in each group). Q fever patients showing fatigue symptoms revealed significantly higher scores in the SOMS, the Whiteley-Index, and higher psychosocial complaints measured with the OQ-45. Their health related Quality of Life was reduced, no differences were found related to perceived social support.

CONCLUSION

Although in our sample fatigue symptoms were common among Q fever patients, we found no increased prevalence of CFS in contrast to several other studies. The combination of fatigue symptoms with other psychosocial symptoms/problems support the view of a biopsychosocial etiology of fatigue symptoms.

A two-year follow-up study of chronic fatigue syndrome comorbid with psychiatric disorders

AIMS

Chronic fatigue syndrome patients often have comorbid psychiatric disorders such as major depressive disorders and anxiety disorders. However, the outcomes of chronic fatigue syndrome and the comorbid psychiatric disorders and the interactions between them are unknown. Therefore, a two-year prospective follow-up study was carried out on chronic fatigue syndrome patients with comorbid psychiatric disorders.

METHODS

A total of 155 patients who met the Japanese case definition of chronic fatigue syndrome were enrolled in this study. Comorbid psychiatric disorders were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders 4th edition criteria. Patients with comorbid psychiatric disorders received psychiatric treatment in addition to medical therapy for chronic fatigue syndrome. Seventy patients participated in a follow-up interview approximately 24 months later.

RESULTS

Of the 70 patients with chronic fatigue syndrome, 33 patients were diagnosed as having comorbid psychiatric disorders including 18 major depressive disorders. Sixteen patients with psychiatric disorders and eight patients with major depressive disorders did not fulfill the criteria of any psychiatric disorders at the follow up. As for chronic fatigue syndrome, nine out of the 70 patients had recovered at the follow up. There is no significant influence of comorbid psychiatric disorders on the outcome of chronic fatigue syndrome.

CONCLUSIONS

Chronic fatigue syndrome patients have a relatively high prevalence of comorbid psychiatric disorders, especially major depressive disorders. The outcomes of chronic fatigue syndrome and psychiatric disorders are independent. Therefore treatment of comorbid psychiatric disorders is necessary in addition to the medical treatment given for chronic fatigue syndrome.

Possible role for early-life immune insult including developmental immunotoxicity in chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME)

Chronic fatigue syndrome (CFS), also known as myalgic encephalomyelitis (ME) in some countries, is a debilitating disease with a constellation of multi-system dysfunctions primarily involving the neurological, endocrine and immune systems. While substantial information is available concerning the complex dysfunction-associated symptoms of CFS, environmental origins of the disease have yet to be determined. Part of the dilemma in identifying the cause(s) has been the focus on biomarkers (hormones, neurotransmitters, cytokines, infectious agents) that are contemporary with later-life CFS episodes. Yet, recent investigations on the origins of environmental diseases of the neurological, endocrine, reproductive, respiratory and immune systems suggest that early life toxicologic and other insults are pivotal in producing later-life onset of symptoms. As with autism and childhood asthma, CFS can also occur in children where the causes are certainly early-life events. Immune dysfunction is recognized as part of the CFS phenotype but has received comparatively less attention than aberrant neurological or endocrine function. However, recent research results suggest that early life immune insults (ELII) including developmental immunotoxicity (DIT), which is induced by xenobiotics, may offer an important clue to the origin(s) of CFS. The developing immune system is a sensitive and novel target for environmental insult (xenobiotic, infectious agents, stress) with major ramifications for postnatal health risks. Additionally, many prenatal and early postnatal neurological lesions associated with postnatal neurobehavioral diseases are now recognized as linked to prenatal immune insult and inflammatory dysregulation. This review considers the potential role of ELII including DIT as an early-life component of later-life CFS.

Chronic fatigue syndrome

Chronic fatigue syndrome (CFS) is thought to have a worldwide prevalence of 0.4-1% with approximately 240,000 patients in the UK. Diagnosis is based on clinical criteria and critically depends on exclusion of other physical and psychiatric diseases. Studies of pathogenesis have revealed immune system abnormalities and chronic immune activation, dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis, brain abnormalities, evidence of emotional stress (comprising host aspects) and evidence of exogenous insults, for example, various microbial infections (Epstein-Barr virus, enteroviruses, parvovirus B19, Coxiella burnetii and Chlamydia pneumoniae), vaccinations and exposure to organophosphate chemicals and other toxins (comprising environmental aspects). Emotional stress appears to be very important as it reduces the ability of the immune system to clear infections, it's presence has been shown to determine whether or not an individual develops symptoms upon virus infection, and it leads to activation of the HPA axis. But, emotional stress is distinct from depression, the presence of which precludes a diagnosis of CFS. There is no specific treatment for CFS other than the much underutilised approach of specific treatment of virus infections. Current priorities are to understand the molecular pathogenesis of disease in terms of human and virus gene expression, to develop a diagnostic test based on protein biomarkers, and to develop specific curative treatments.