Myalgic encephalomyelitis (ME), also referred to as chronic fatigue syndrome (CFS), is a complex illness that typically presents with disabling fatigue and cognitive and functional impairment. The etiology and management of ME/CFS remain contentious and patients often describe their experiences through social media.

We explored public discourse on Twitter (rebranded as X) to understand the concerns and priorities of individuals living with ME/CFS, with a focus on (1) the COVID-19 pandemic and (2) publication of the 2021 UK National Institute for Health and Care Excellence (NICE) guidelines on the diagnosis and management of ME/CFS.

We used the Twitter application programming interface to collect tweets related to ME/CFS posted between January 1, 2010, and January 30, 2024. Tweets were sorted into 3 chronological periods (pre-COVID-19 pandemic, post-COVID-19 pandemic, and post-UK 2021 NICE Guidelines publication). A Robustly Optimized Bidirectional Embedding Representations from Transformers Pretraining Approach (RoBERTa) language processing model was used to categorize the sentiment of tweets as positive, negative, or neutral. We identified tweets that mentioned COVID-19, the UK NICE guidelines, and key themes identified through latent Dirichlet allocation (ie, fibromyalgia, research, and treatment). We sampled 1000 random tweets from each theme to identify subthemes and representative quotes.

We retrieved 906,404 tweets, of which 427,824 (47.2%) were neutral, 369,371 (40.75%) were negative, and 109,209 (12.05%) were positive. Over time, both the proportion of negative and positive tweets increased, and the proportion of neutral tweets decreased (P<.001 for all changes). Tweets mentioning fibromyalgia acknowledged similarities with ME/CFS, stigmatization associated with both disorders, and lack of effective treatments. Treatment-related tweets often described frustration with ME/CFS labeled as mental illness, dismissal of concerns by health care providers, and the need to seek out "good physicians" who viewed ME/CFS as a physical disorder. Tweets on research typically praised studies of biomarkers and biomedical therapies, called for greater investment in biomedical research, and expressed frustration with studies suggesting a biopsychosocial etiology for ME/CFS or supporting management with psychotherapy or graduated activity. Tweets about the UK NICE guidelines expressed frustration with the 2007 version that recommended cognitive behavioral therapy and graded exercise therapy, and a prolonged campaign by advocacy organizations to influence subsequent versions. Tweets showed high acceptance of the 2021 UK NICE guidelines, which were seen to validate ME/CFS as a biomedical disease and recommended against graded exercise therapy. Tweets about COVID-19 often noted overlaps between post-COVID-19 condition and ME/CFS, including claims of a common biological pathway, and advised there was no cure for either condition.

Our findings suggest research is needed to inform how best to support patients' engagement with evidence-based care. Furthermore, while patient involvement with ME/CFS research is critical, unmanaged intellectual conflicts of interest may threaten the trustworthiness of research efforts.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex heterogeneous multiorgan disease that can have severe impact on individuals' quality of life. Diagnosis of ME/CFS is based on symptom presentation, and a significant goal for the field is to establish meaningful subtypes. The heterogeneity in the literature suggests that individuals living with ME/CFS may suffer from overlapping but different underlying pathophysiological mechanisms. We enrolled 40 participants with ME/CFS and 41 matched healthy control subjects at the Bragée Clinic in Sweden. We assessed plasma samples from both ME/CFS cases and control groups and cerebrospinal fluid (CSF) samples from individuals with ME/CFS. We investigated dysregulated pathways and disease profiles through clinical questionnaires; multiplex analyses of cytokines, hormones, and matrix metalloproteinases; pathogen seroreactivity through peptide display bacteria libraries; and high-throughput microarray for autoantibodies. All samples used were from humans. We show altered interaction patterns between circulating biological factors in plasma of ME/CFS participants. Our analysis of CSF from individuals with ME/CFS revealed different immunotypes of disease. We found 2 patient clusters based on matrix metalloproteinases profiles. The subgroups had similar clinical presentation but distinct pathogen exposure and CSF inflammatory profiles. Our findings shed light on ME/CFS immune phenotypes and generate hypotheses for future research in disease pathogenesis and treatment development by exploring disease subgroups.

People with Myalgic Encephalomyelitis (ME/CFS; sometimes referred to as chronic fatigue syndrome) experience poor health-related quality of life and only rarely recover. ME/CFS has no curative treatment, and no single diagnostic test. Public health and policy decisions relevant to ME/CFS require knowledge of its prevalence and barriers to diagnosis. However, people with ME/CFS report lengthy diagnostic delays and prevalence estimates vary greatly due to uneven diagnosis and misdiagnosis. Factors that influence diagnosis could be revealed by stratifying a single population by gender, age and ethnicity.

Hospital Episode Statistics data, routinely collected by the NHS in England, was downloaded from the Feasibility Self-Service of NHS DigiTrials. This was used to stratify individuals with the ICD-10 code that best reflects ME/CFS symptoms (G93.3) according to age, self-reported gender and ethnicity, General Practice and NHS England Integrated Care Board (ICB).

In all, 100,055 people in England had been diagnosed with ME/CFS (ICD-10:G93.3) between April 1 1989 and October 7 2023, 0.16% of all registered patients. Of these, 79,445 were females and 20,590 males, a female-to-male ratio of 3.88:1. Female relative to male prevalence peaked at about 6-to-1 in individuals' fourth and fifth decades of life. Prevalence varied widely across the 42 ICBs: 0.086%-0.82% for females and 0.024%-0.21% for males. White individuals were approximately fivefold more likely to be diagnosed with ME/CFS than others; Black, Asian or Chinese ethnicities are associated with particularly low rates of ME/CFS diagnoses. This ethnicity bias is stronger than for other common diseases. Among active English GP practices, 176 (3%) had no registered ME/CFS patients. Eight ICBs (19%) each contained fewer than 8 other-than-white individuals with a G93.3 code despite their registers containing a total of 293,770 other-than-white patients.

Other-than-white ethnic groups, older females (> 60y), older males (> 80y), and people living in areas of multiple deprivation are disproportionately undiagnosed with ME/CFS. Lifetime prevalence of ME/CFS for English females and males may be as high as 0.92% and 0.25%, respectively, or approximately 404,000 UK individuals overall (0.6%). This improved estimate of ME/CFS prevalence allows more accurate assessment of the socioeconomic and disease burden imposed by ME/CFS.

With widespread late- and under-diagnosing, health register code G93.3 data cannot offer an unbiased sampling frame for myalgic encephalomyelitis, complicating prevalence and demographic distribution assessments. It also remains unclear if all G93.3 cases would meet the Canada Consensus Criteria (CCC). This article describes a novel methodological approach to addressing selection bias when estimating a CCC population's characteristics, applying an online respondent-driven sampling approach and validated DePaul University algorithms. In a sample of 660 respondents, we assess possible bias in the G93.3 diagnosis by regressing sociodemographic factors on G93.3 status, controlling for medical factors. Results support suggestions that G93.3 register data are biased against those socially deprived.

Long COVID-19 (LC) patients experience a number of chronic idiopathic symptoms that are highly similar to those of post-viral myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). We have therefore performed a systematic review and meta-analysis to determine the proportion of LC patients that satisfy ME/CFS diagnostic criteria.

Clinical studies published between January 2020 and May 2023 were identified using the PubMed, Web of Science, Embase and CINAHL databases. Publication inclusion/exclusion criteria were formulated using the global CoCoPop framework. Data were pooled using a random-effects model with a restricted maximum-likelihood estimator. Study quality was assessed using the Joanna Briggs Institute critical assessment tool.

We identified 13 eligible studies that reported a total of 1973 LC patients. Our meta-analysis indicated that 51% (95% CI, 42%-60%) of LC patients satisfied ME/CFS diagnostic criteria, with fatigue, sleep disruption, and muscle/joint pain being the most common symptoms. Importantly, LC patients also experienced the ME/CFS hallmark symptom, post-exertional malaise.

Our study not only demonstrates that LC patients exhibit similar symptom clusters to ME/CFS, but that approximately half of LC patients satisfy a diagnosis of ME/CFS. Our findings suggest that current ME/CFS criteria could be adapted to the identification of a subset of LC patients that may facilitate the standardised diagnosis, management and the recruitment for clinical studies in the future.

Long COVID is a debilitating, multisystemic illness following a SARS-CoV-2 infection whose duration may be indefinite. Over four years into the pandemic, little knowledge has been generated from clinical trials. We analyzed the information available on ClinicalTrials.gov, and found that the rigor and focus of trials vary widely, and that the majority test non-pharmacological interventions with insufficient evidence. We highlight promising trials underway, and encourage the proliferation of clinical trials for treating Long COVID and other infection-associated chronic conditions and illnesses (IACCIs). We recommend several guidelines for Long COVID trials: First, pharmaceutical trials with potentially curative, primary interventions should be prioritized, and both drug repurposing and new drug development should be pursued. Second, study designs should be both rigorous and accessible, e.g., triple-blinded randomized trials that can be conducted remotely, without participants needing to leave their homes. Third, studies should have multiple illness comparator cohorts for IACCIs such as myalgic encephalomyelitis (ME/CFS) and dysautonomia, and screen for the full spectrum of symptomatology and pathologies of these illnesses. Fourth, studies should consider inclusion/exclusion criteria with an eye towards equity and breadth of representation, including participants of all races, ethnicities, and genders most impacted by COVID-19, and including all levels of illness severity. Fifth, involving patient-researchers in all aspects of studies brings immensely valuable perspectives that will increase the impact of trials. We also encourage the development of efficient clinical trial designs including methods to study several therapies in parallel.

Parallel-group randomised controlled trial.

Adolescents aged 11-17 years, diagnosed with myalgic encephalomyelitis/chronic fatigue syndrome and with no local specialist treatment centre, were referred to a specialist service in South West England.

Fatigue In Teenagers on the interNET in the National Health Service is a web-based myalgic encephalomyelitis/chronic fatigue syndrome-focused cognitive-behavioural therapy programme for adolescents, supported by individualised written, asynchronous electronic consultations with a clinical psychologist/cognitive-behavioural therapy practitioner. The comparator was videocall-delivered activity management with a myalgic encephalomyelitis/chronic fatigue syndrome clinician. Both treatments were intended to last 6 months.

Estimate the effectiveness of Fatigue In Teenagers on the interNET in the National Health Service compared to Activity Management for paediatric myalgic encephalomyelitis/chronic fatigue syndrome. Estimate the effectiveness of Fatigue In Teenagers on the interNET in the National Health Service compared to Activity Management for those with mild/moderate comorbid mood disorders. From a National Health Service perspective, estimate the cost-effectiveness of Fatigue In Teenagers on the interNET in the National Health Service compared to Activity Management over a 12-month horizon.

36-item Short Form Health Survey Physical Function subscale at 6 months post randomisation.

Web-based, using minimisation with a random component to balance allocated groups by age and gender.

While the investigators were blinded to group assignment, this was not possible for participants, parents/carers and therapists.

The treatment of 314 adolescents was randomly allocated, 155 to Fatigue In Teenagers on the interNET in the National Health Service. Mean age was 14 years old and 63% were female.

At 6 months, participants allocated to Fatigue In Teenagers on the interNET in the National Health Service were more likely to have improved physical function (mean 60.5, standard deviation 29.5, n = 127) compared to Activity Management (mean 50.3, standard deviation 26.5, n = 138). The mean difference was 8.2 (95% confidence interval 2.7 to 13.6, p = 0.003). The result was similar for participants meeting the National Institute for Health and Care Excellence 2021 diagnostic criteria.

Fatigue In Teenagers on the interNET in the National Health Service participants attended, on average, half a day more school per week at 6 months than those allocated Activity Management, and this difference was maintained at 12 months. There was no strong evidence that comorbid mood disorder impacted upon the relative effectiveness of the two interventions. Similar improvement was seen in the two groups for pain and the Clinical Global Impression scale, with a mixed picture for fatigue. Both groups continued to improve, and no clear difference in physical function remained at 12 months [difference in means 4.4 (95% confidence interval -1.7 to 10.5)]. One or more of the pre-defined measures of a worsening condition in participants during treatment, combining therapist and patient reports, were met by 39 (25%) participants in the Fatigue In Teenagers on the interNET in the National Health Service group and 42 (26%) participants in the Activity Management group. A small gain was observed for the Fatigue In Teenagers on the interNET in the National Health Service group compared to Activity Management in quality-adjusted life-years (0.002, 95% confidence interval -0.041 to 0.045). From an National Health Service perspective, the costs were £1047.51 greater in the Fatigue In Teenagers on the interNET in the National Health Service group (95% confidence interval £624.61 to £1470.41). At a base cost-effectiveness threshold of £20,000 per quality-adjusted life-year, the incremental cost-effectiveness ratio was £457,721 with incremental net benefit of -£1001 (95% confidence interval -£2041 to £38).

At 6 months post randomisation, compared with Activity Management, Fatigue In Teenagers on the interNET in the National Health Service improved physical function and school attendance. The additional cost of Fatigue In Teenagers on the interNET in the National Health Service and limited sustained impact mean it is unlikely to be cost-effective.

This trial is registered as ISRCTN18020851.

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 14/192/109) and is published in full in Health Technology Assessment; Vol. 28, No. 70. See the NIHR Funding and Awards website for further award information.

This study aimed to assess plasma galectin-9 (Gal-9) and artemin (ARTN) concentrations as potential biomarkers to differentiate individuals with Long COVID (LC) patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) from SARS-CoV-2 recovered (R) and healthy controls (HCs). Receiver operating characteristic (ROC) curve analysis determined a cut-off value of plasma Gal-9 and ARTN to differentiate LC patients from the R group and HCs in two independent cohorts. Positive correlations were observed between elevated plasma Gal-9 levels and inflammatory markers (e.g. SAA and IP-10), as well as sCD14 and I-FABP in LC patients. Gal-9 also exhibited a positive correlation with cognitive failure scores, suggesting its potential role in cognitive impairment in LC patients with ME/CFS. This study highlights plasma Gal-9 and/or ARTN as sensitive screening biomarkers for discriminating LC patients from controls. Notably, the elevation of LPS-binding protein in LC patients, as has been observed in HIV infected individuals, suggests microbial translocation. However, despite elevated Gal-9, we found a significant decline in ARTN levels in the plasma of people living with HIV (PLWH). Our study provides a novel and important role for Gal-9/ARTN in LC pathogenesis.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a long-term debilitating illness characterised by profound and persistent fatigue (JAMA: The Journal of the American Medical Association, 313, 2015, 1101). The current study aims to explore the experiences of women with ME/CFS living with their partners during the COVID-19 pandemic in the United Kingdom.

The study adopted a qualitative design comprising semi-structured interviews with participants. Interviews were analysed using thematic analysis (TA).

Participants were women with ME/CFS (n = 21) recruited through ME/CFS support groups in the United Kingdom. All participants were in romantic relationships and lived with their partners.

Data were organised into three themes: (1) lockdown disrupting routine, (2) reducing difference and (3) fear of getting COVID-19. People with ME/CFS found that lockdown disrupted their well-established routines. Although routines were disrupted by partners and increased working-from-home practices, participants found having partners at home helpful. People with ME/CFS believed that the changes induced by the pandemic reduced the differences between themselves and the outside world which, prior to lockdown, had felt prominent. They were fearful of getting COVID-19 as they believed this would make their ME/CFS worse. This meant that for people with ME/CFS, the lifting of the lockdown restrictions was an anxiety-provoking time, hence impacting symptoms. People with ME/CFS continued to adhere to government guidelines after national restrictions were eased.

This study outlines the experiences of women with ME/CFS during COVID-19, alongside the long-term impact this has had due to the changes that the pandemic imposed. These findings may have implications for those with long COVID.

Post COVID-19 Condition (PCC), being persistent COVID-19 symptoms, is reminiscent of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)-a chronic multi-systemic illness characterised by neurocognitive, autonomic, endocrinological and immunological disturbances. This novel cross-sectional investigation aims to: (1) compare symptoms among people with ME/CFS (pwME/CFS) and people with PCC (pwPCC) to inform developing PCC diagnostic criteria; and (2) compare health outcomes between patients and people without acute or chronic illness (controls) to highlight the illness burdens of ME/CFS and PCC.

Sociodemographic and health outcome data were collected from n = 61 pwME/CFS, n = 31 pwPCC and n = 54 controls via validated, self-administered questionnaires, including the 36-Item Short-Form Health Survey version 2 (SF-36v2) and World Health Organization Disability Assessment Schedule version 2.0 (WHODAS 2.0). PwME/CFS and pwPCC also provided self-reported severity and frequency of symptoms derived from the Canadian and International Consensus Criteria for ME/CFS and the World Health Organization case definition for PCC.

Both illness cohorts similarly experienced key ME/CFS symptoms. Few differences in symptoms were observed, with memory disturbances, muscle weakness, lymphadenopathy and nausea more prevalent, light-headedness more severe, unrefreshed sleep more frequent, and heart palpitations less frequent among pwME/CFS (all p < 0.05). The ME/CFS and PCC participants' SF-36v2 or WHODAS 2.0 scores were comparable (all p > 0.05); however, both cohorts returned significantly lower scores in all SF-36v2 and WHODAS 2.0 domains when compared with controls (all p < 0.001).

This Australian-first investigation demonstrates the congruent and debilitating nature of ME/CFS and PCC, thereby emphasising the need for multidisciplinary care to maximise patient health outcomes.

The primary focus of this research is the proposition of a methodological framework for the clinical application of the long COVID symptoms and severity score (LC-SSS). This tool is not just a self-reported assessment instrument developed and validated but serves as a standardized, quantifiable means to monitor the diverse and persistent symptoms frequently observed in individuals with long COVID.

A 3-stage process was used to develop, validate, and establish scoring standards for the LC-SSS. Validation measures included correlations with other patient-reported measures, confirmatory factor analysis, Cronbach's α for internal consistency, and test-retest reliability. Scoring standards were determined using K-means clustering, with comparative assessments made against hierarchical clustering and the Gaussian Mixture Model.

The LC-SSS showed correlations with EuroQol 5-Dimension 5-Level (rs = -0.55), EuroQol visual analog scale (rs = -0.368), Patient Health Questionnaire-9 (rs = 0.538), Beck Anxiety Inventory (rs = 0.689), and Insomnia Severity Index (rs = 0.516), confirming its construct validity. Structural validity was good with a comparative fit index of 0.969, with Cronbach's α of 0.93 indicating excellent internal consistency. Test-retest reliability was also satisfactory (intraclass correlation coefficient 0.732). K-means clustering identified 3 distinct severity categories in individuals living with long COVID, providing a basis for personalized treatment strategies.

The LC-SSS provides a robust and valid tool for assessing long COVID. The severity categories established via K-means clustering demonstrate significant variation in symptom severity, informing personalized treatment and improving care quality for patients with long COVID.

In this six-year follow-up study, we used patient-reported outcome measures (PROMs) to compare values at baseline, at 18 months, and at six-year follow up from the CycloME and the RituxME trials.

Based on the hypothesis that ME/CFS in a subgroup of patients is a variant of an autoimmune disease, we performed two clinical trials between 2014 and 2017. The RituxME trial was a randomized, double-blind and placebo-controlled phase III trial of 151 patients, assessing the B-cell depleting antibody rituximab. The CycloME trial was an open-label phase II trial of 40 patients using intravenous cyclophosphamide. Here we report six-year follow-up from both trials, using the Short Form 36 Physical Function (SF-36 PF) and DePaul short form (DSQ-SF) questionnaires.

Of the patients available after six years, 75.7% of RituxME and 94.4% of CycloME patients participated. In the RituxME rituximab group, the mean SF-36 PF scores were 32.9 at baseline, 42.4 at 18 months and 45.5 at six years. In the placebo group, the mean SF-36 PF scores were 32.3 at baseline, 45.5 at 18 months and 43.1 at six years. In the CycloME trial, mean SF-36 PF increased from 35.4 at baseline to 54.4 at 18 months, and 56.7 at six years. At six-year follow-up, 44.1% of cyclophosphamide-, 27.6% of rituximab- and 20.4% of placebo-treated patients had an SF-36 PF ≥ 70, and further, 17.6%, 8.6% and 7.4% of the corresponding patient groups had an SF-36 PF ≥ 90, which is within normal range. In terms of worsening at six years, 5.9% of cyclophosphamide-treated, 10.3% of rituximab-, and 14.8% of placebo-treated patients had a drop in SF-36 PF of 20 points or more from baseline. There were no serious unexpected adverse reactions.

After six years, 44.1% of the cyclophosphamide group scored an SF-36 PF of at least 70, and 17.6% of at least 90, suggesting that cyclophosphamide in a subgroup may modulate the disease course in a beneficial way. However, cyclophosphamide carries toxicity concerns and should not be used for ME/CFS patients outside clinical trials. Rather, these data should encourage efforts to better understand the disease mechanisms and to search for targeted and less toxic immune modulatory treatment for this patient group.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and coronavirus disease 2019 (COVID-19) have been around for more than 3 years now. However, due to constant viral evolution, novel variants are emerging, leaving old treatment protocols redundant. As treatment options dwindle, infection rates continue to rise and seasonal infection surges become progressively common across the world, rapid solutions are required. With genomic and proteomic methods generating enormous amounts of data to expand our understanding of SARS-CoV-2 biology, there is an urgent requirement for the development of novel therapeutic methods that can allow translational research to flourish. In this review, we highlight the current state of COVID-19 in the world and the effects of post-infection sequelae. We present the contribution of translational research in COVID-19, with various current and novel therapeutic approaches, including antivirals, monoclonal antibodies and vaccines, as well as alternate treatment methods such as immunomodulators, currently being studied and reiterate the importance of translational research in the development of various strategies to contain COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the respiratory distress condition known as COVID-19. This disease broadly affects several physiological systems, including the gastrointestinal, renal, and central nervous (CNS) systems, significantly influencing the patient's overall quality of life. Additionally, numerous risk factors have been suggested, including gender, body weight, age, metabolic status, renal health, preexisting cardiomyopathies, and inflammatory conditions. Despite advances in understanding the genome and pathophysiological ramifications of COVID-19, its precise origins remain elusive. SARS-CoV-2 interacts with a receptor-binding domain within angiotensin-converting enzyme 2 (ACE2). This receptor is expressed in various organs of different species, including humans, with different abundance. Although COVID-19 has multiorgan manifestations, the main pathologies occur in the lung, including pulmonary fibrosis, respiratory failure, pulmonary embolism, and secondary bacterial pneumonia. In the post-COVID-19 period, different sequelae may occur, which may have various causes, including the direct action of the virus, alteration of the immune response, and metabolic alterations during infection, among others. Recognizing the serious adverse health effects associated with COVID-19, it becomes imperative to comprehensively elucidate and discuss the existing evidence surrounding this viral infection, including those related to the pathophysiological effects of the disease and the subsequent consequences. This review aims to contribute to a comprehensive understanding of the impact of COVID-19 and its long-term effects on human health.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a chronic, debilitating disease characterised by a wide range of symptoms that severely impact all aspects of life. Despite its significant prevalence, ME/CFS remains one of the most understudied and misunderstood conditions in modern medicine. ME/CFS lacks standardised diagnostic criteria owing to variations in both inclusion and exclusion criteria across different diagnostic guidelines, and furthermore, there are currently no effective treatments available. Moving beyond the traditional fragmented perspectives that have limited our understanding and management of the disease, our analysis of current information on ME/CFS represents a significant paradigm shift by synthesising the disease's multifactorial origins into a cohesive model. We discuss how ME/CFS emerges from an intricate web of genetic vulnerabilities and environmental triggers, notably viral infections, leading to a complex series of pathological responses including immune dysregulation, chronic inflammation, gut dysbiosis, and metabolic disturbances. This comprehensive model not only advances our understanding of ME/CFS's pathophysiology but also opens new avenues for research and potential therapeutic strategies. By integrating these disparate elements, our work emphasises the necessity of a holistic approach to diagnosing, researching, and treating ME/CFS, urging the scientific community to reconsider the disease's complexity and the multifaceted approach required for its study and management.

This service evaluation explored the experiences of families receiving care in a paediatric chronic fatigue service. The evaluation aimed to improve service provision across paediatric chronic fatigue services more widely.

Children and young people aged 7-18 years (n  =  25) and parents/carers (n  =  25) completed a postal survey exploring experiences of a paediatric chronic fatigue service. Quantitative data were analysed descriptively, and qualitative data were analysed using thematic analysis.

Most service usersand parents/carers (88%) agreed that the service met their needs, that they felt supported by staff, and most notably, a large portion (74%) reported the team increased their activity levels. A small number disagreed (7%) with statements relating to positive links with other services, ease of talking to staff and suitability of appointment type. The thematic analysis revealed three themes: help managing chronic fatigue syndrome, experience of professional support and accessibility of service. Families reported benefiting from increased understanding of chronic fatigue syndrome, learning new strategies, the team linking with schools, feeling validated and mental health support. Accessibility was a particular problem including the service location, setup of appointments and difficulty contacting the team.

The evaluation presents recommendations for paediatric Chronic Fatigue services to improve service user experiences.

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating multisystemic disease characterized by a complex, incompletely understood etiology. Methods: To facilitate future clinical and translational research, a multicenter German ME/CFS registry (MECFS-R) was established to collect comprehensive, longitudinal, clinical, epidemiological, and laboratory data from adults, adolescents, and children in a web-based multilayer-secured database. Results: Here, we present the research protocol and first results of a pilot cohort of 174 ME/CFS patients diagnosed at two specialized tertiary fatigue centers, including 130 (74.7%) adults (mean age 38.4; SD 12.6) and 43 (25.3%) pediatric patients (mean age 15.5; SD 4.2). A viral trigger was identified in 160/174 (92.0%) cases, with SARS-CoV-2 in almost half of them. Patients exhibited severe functional and social impairment, as reflected by a median Bell Score of 30.0 (IQR 30.0 to 40.0) and a poor health-related quality of life assessed with the Short Form-36 health survey, resulting in a mean score of 40.4 (SD 20.6) for physical function and 59.1 (SD 18.8) for mental health. Conclusions: The MECFS-R provides important clinical information on ME/CFS to research and healthcare institutions. Paired with a multicenter biobank, it facilitates research on pathogenesis, diagnostic markers, and treatment options. Trial registration: ClinicalTrials.gov NCT05778006.

Physiotherapy interventions effectively improved fatigue and physical functioning in non-COVID patients with myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS). There is a research gap on the effectiveness of physiotherapy interventions versus drug management on ME/CFS in post-COVID-19 conditions (PCC).

We planned a three-arm prospective randomized control trial on 135 PCC cases with ME/CFS who are diagnosed between 20 November 2023 and 20 May 2024 from a population-based cohort. The study aims to determine the effectiveness of physiotherapy interventions as adapted physical activity and therapeutic exercise (APTE) provided in institution-based care versus telemedicine compared with drug management (DM). Participants will be assigned to three groups with the concealed location process and block randomization with an enrollment ratio of 1:1:1. The post-treatment evaluation will be employed after 2 months of interventions, and follow-up will be taken after 6 months post-intervention. The Chalder fatigue scale will measure the primary outcome of fatigue. SF-36 and the disability-adjusted life years (DALYs) will measure the secondary outcome of physical functioning and episodic disability.

This study will address the research gap to determine the appropriate approach of physiotherapy or drug management for ME/CFS in PCC cases. The future direction of the study will contribute to developing evidence-based practice in post-COVID-19 condition rehabilitation.

The trial is registered prospectively from a primary Clinical Trial Registry side of WHO CTRI/2024/01/061987. Registered on 29 January 2024.

Current views on immunity support the idea that immunity extends beyond defense functions and is tightly intertwined with several other fields of biology such as virology, microbiology, physiology and ecology. It is also critical for our understanding of autoimmunity and cancer, two topics of great biological relevance and for critical public health considerations such as disease prevention and treatment. Central to this review, the immune system is known to interact intimately with the nervous system and has been recently hypothesized to be involved not only in autonomic and limbic bio-behaviors but also in cognitive function. Herein we review the structural architecture of the brain network involved in immune response. Furthermore, we elaborate upon the implications of inflammatory processes affecting brain-immune interactions as reported recently in pathological conditions due to SARS-Cov-2 virus infection, namely in acute and post-acute COVID-19. Moreover, we discuss how current neuroimaging techniques combined with ad hoc clinical autopsies and histopathological analyses could critically affect the validity of clinical translation in studies of human brain-immune interactions using neuroimaging. Advances in our understanding of brain-immune interactions are expected to translate into novel therapeutic avenues in a vast array of domains including cancer, autoimmune diseases or viral infections such as in acute and post-acute or Long COVID-19.

Myalgic encephalomyelitis (ME), also called chronic fatigue syndrome (CFS), is characterised by persistent fatigue, postexertional malaise, and cognitive dysfunction. It is a complex, long-term, and debilitating illness without widely effective treatments. This study describes the treatment choices and experiences of ME/CFS patients who have experienced variable levels of recovery.

Interpretive description study consisting of semi-structured qualitative interviews with 33 people who met the US Centers for Disease Control (2015) diagnostic criteria for ME/CFS and report recovery or symptom improvement.

Twenty-six participants endorsed partial recovery, and seven reported full recovery from ME/CFS. Participants reported expending significant time and energy to identify, implement, and adapt therapeutic interventions, often without the guidance of a medical practitioner. They formulated individualised treatment plans reflecting their understanding of their illness and personal resources. Most fully recovered participants attributed their success to mind-body approaches.

Patients with ME/CFS describe independently constructing and managing treatment plans, due to a lack of health system support. Stigmatised and dismissive responses from clinicians precipitated disengagement from the medical system and prompted use of other forms of treatment.

Chronic fatigue syndrome (CFS) is a debilitating multisystem disorder that can lead to various pathophysiological abnormalities and symptoms, including insomnia, gastrointestinal disorders, and anxiety. Due to the side effects of currently available drugs, there is a growing need for safe and effective nondrug therapies. The Prolong Life With Nine Turn (PLWNT) Qigong method is a system of mind-body exercise with restorative benefits that can alleviate the clinical symptoms of CFS and impart a significant inhibitory effect. Various studies have proven the treatment efficacy of PLWNT; however, the impact on insomnia, gastrointestinal disorders, and anxiety in patients with CFS has not yet been investigated.

This study aims to evaluate the efficacy and safety of the PLWNT method in terms of its effects on fatigue, insomnia, anxiety, and gastrointestinal symptoms in patients with CFS.

We will conduct a randomized, analyst-blinded, parallel-controlled trial with a 12-week intervention and 8-week follow-up. A total of 208 patients of age 20-60 years will be recruited. The patients will be randomly divided into a PLWNT Qigong exercise group (PLWNT Group) and a control group treated with cognitive behavioral therapy at a ratio of 1:1. Participants from the treatment groups will be taught by a highly qualified professor at the Shanghai University of Traditional Chinese Medicine once a week and will be supervised via web during the remaining 6 days at home, over 12 consecutive weeks. The primary outcome will be the Multidimensional Fatigue Inventory 20, while the secondary outcomes include the Pittsburgh Sleep Quality Index, Gastrointestinal Symptom Rating Scale, Hospital Anxiety and Depression Scale, functional magnetic resonance imaging, gut microbiota, and peripheral blood.

The study was approved by the ethics committee of Shanghai Municipal Hospital of Traditional Chinese Medicine in March 2022 (Ethics Approval Number 2022SHL-KY-05). Recruitment started in July 2022. The intervention is scheduled to be completed in December 2024, and data collection will be completed by the end of January 2025. Over the 3-year recruitment period, 208 participants will be recruited. Data management is still in progress; therefore, data analysis has yet to be performed.

This randomized trial will evaluate the effectiveness of the PLWNT method in relieving fatigue, insomnia, anxiety, and gastrointestinal symptoms in patients with CFS. If proven effective, it will provide a promising alternative intervention for patients with CFS.

China Clinical Trials Registry ChiCTR2200061229; https://www.chictr.org.cn/showproj.html?proj=162803.

PRR1-10.2196/53347.

Interest in the coronavirus disease 2019 (COVID-19) has progressively decreased lately, mainly due to the great effectivity of vaccines. Furthermore, no new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants able to circumvent the protection of these vaccines, while presenting high transmissibility and/or lethality, have appeared. However, long COVID has emerged as a huge threat to human health and economy globally. The human microbiota plays an important role in health and disease, participating in the modulation of innate and adaptive immune responses. Thus, multiple studies have found that the nasopharyngeal microbiota is altered in COVID-19 patients, with these changes associated with the onset and/or severity of the disease. Nevertheless, although dysbiosis has also been reported in long COVID patients, mainly in the gut, little is known about the possible involvement of the microbiota in the development of this disease. Therefore, in this work, we aim to fill this gap in the knowledge by discussing and comparing the most relevant studies that have been published in this field up to this point. Hence, we discuss that the relevance of long COVID has probably been underestimated, and that the available data suggest that the microbiota could be playing a pivotal role on the pathogenesis of the disease. Further research to elucidate the involvement of the microbiota in long COVID will be essential to explore new therapeutic strategies based on manipulation of the microbiota.

Infectious mononucleosis after primary infection with Epstein-Barr virus (EBV-IM) has been linked to the development of myalgic encephalomyelitis/chronic fatigue-syndrome (ME/CFS) in children, adolescents, and young adults. Here, we present clinical phenotypes and follow-up data from a first German cohort of young people with ME/CFS following EBV-IM.

12 adolescents and 13 young adults were diagnosed with IM-triggered ME/CFS at our specialized tertiary outpatient service by clinical criteria requiring post-exertional malaise (PEM) and a history of confirmed EBV primary infection as triggering event. Demographic information, laboratory findings, frequency and severity of symptoms, physical functioning, and health-related quality of life (HRQoL) were assessed and re-evaluated 6 and 12 months later.

Young adults displayed more severe symptoms as well as worsening of fatigue, physical and mental functioning, and HRQoL throughout the study, compared to adolescents. After one year, 6/12 (54%) adolescents no longer met the diagnostic criteria for ME/CFS while all young adults continued to fulfill the Canadian consensus criteria. Improvement in adolescents was evident in physical functioning, symptom frequency and severity, and HRQoL, while young adults showed little improvement. EBV serology and EBV DNA load did not correlate with distinct clinical features of ME/CFS, and clinical chemistry showed no evidence of inflammation. Remarkably, the median time from symptom onset to ME/CFS diagnosis was 13.8 (IQR: 9.1-34.9) months.

ME/CFS following EBV-IM is a severely debilitating disease often diagnosed late and with limited responses to conventional medical care, especially in adults. Although adolescents may have a better prognosis, their condition can fluctuate and significantly impact their HRQoL. Our data emphasize that biomarkers and effective therapeutic options are also urgently needed to improve medical care and pave the way to recovery.

Long COVID, also known as post-acute sequelae of SARS-CoV-2 infection (PASC), refers to a constellation of persistent symptoms and health issues that continue beyond the acute phase of COVID-19. This chapter provides an overview of the pathogenesis, risk factors, manifestations, major findings, and diagnosis and treatment strategies associated with Long COVID. Hypotheses regarding the pathogenesis of Long COVID are discussed, encompassing various factors such as persistent viral reservoirs, immune dysregulation with or without reactivation of herpesviruses (e.g., Epstein-Barr Virus and human herpesvirus), dysbiosis, autoimmunity triggered by infection, endothelial dysfunction, microvessel blood clotting, and dysfunctional brainstem and/or vagal signaling. The chapter also highlights the risk factors associated with Long COVID and its occurrence in children. The major findings of Long COVID, including immune dysregulation, vessel and tissue damage, neurological and cognitive pathology, eye symptoms, endocrinal issues, myalgic encephalomyelitis and chronic fatigue syndrome, reproductive system involvement, respiratory and gastrointestinal symptoms, and the chronology of symptoms, are thoroughly explored. Lastly, the chapter discusses the challenges and current approaches in the diagnosis and treatment of Long COVID, emphasizing the need for multidisciplinary care and individualized management strategies.

The purpose of this study is to analyze the influencing factors associated with Long-COVID in patients infected with Omicron variant of COVID-19 in Changchun City, Jilin Province, China three months after discharge in March 2022.

In this study, we conducted a telephone follow-up based on the real-world data collected from the Affiliated Hospital to Changchun University of Chinese Medicine, Changchun Tongyuan Shelter Hospital and Changchun Infectious Disease Hospital during the COVID-19 epidemic in Changchun in March 2022. We used the Global COVID-19 Clinical Platform Case Report Form for Post COVID condition as a follow-up questionnaire to collect the general information, past medical history, clinical symptoms, COVID-19 vaccine inoculation doses, and other relevant information to analyze the symptom characteristics of COVID-19 patients three months after discharge from the hospital and related factors affecting Long COVID.

A total of 1,806 patients with COVID-19 were included in this study, 977 males and 829 females, with a mean age of 38.5 [30.0, 49.4] years, and the number of female patients suffering from Long COVID (50.87%) was greater than male patients (p = 0.023). The binary logistic regression analysis of factors influencing Long COVID showed that smoking history (OR (95%CI) = 0.551(0.425-0.714), p < 0.001, taking never smoking as a reference), allergy history (OR (95%CI) = 1.618 (1.086-2.413), p-value 0.018, taking no allergy as a reference), first symptoms (OR (95%CI) = 0.636 (0.501-0.807), p < 0.001, with no first symptoms as reference) and COVID-19 vaccine inoculation doses (OR (95%CI) = 1.517 (1.190-1.933), p-value 0.001, with ≤ 2 doses of COVID-19 vaccine inoculation doses as reference) constituted its influencing factors. The first symptoms of patients on admission mainly included fever (512 cases, 71.81%), cough (279 cases, 39.13%) and dry or itchy throat (211 cases, 29.59%). The most common symptoms of Long COVID were persistent fatigue (68 cases), amnesia (61 cases), insomnia (50 cases) and excessive sweating (50 cases).

The first symptoms on admission were predominantly fever, cough and dry or itchy throat. The most common symptoms of Long COVID were persistent fatigue, amnesia, insomnia and excessive sweating, and female patients were at a higher risk of Long COVID.

The coronavirus disease 2019 (COVID-19), instigated by the zoonotic Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), rapidly transformed from an outbreak in Wuhan, China, into a widespread global pandemic. A significant post-infection condition, known as 'long- COVID-19' (or simply 'long- COVID'), emerges in a substantial subset of patients, manifesting with a constellation of over 200 reported symptoms that span multiple organ systems. This condition, also known as 'post-acute sequelae of SARS-CoV-2 infection' (PASC), presents a perplexing clinical picture with far-reaching implications, often persisting long after the acute phase. While initial research focused on the immediate pulmonary impact of the virus, the recognition of COVID-19 as a multiorgan disruptor has unveiled a gamut of protracted and severe health issues. This review summarizes the primary effects of long COVID on the respiratory, cardiovascular, and nervous systems. It also delves into the mechanisms underlying these impacts and underscores the critical need for a comprehensive understanding of long COVID's pathogenesis.

The condition known as chronic fatigue syndrome or myalgic encephalomyelitis (CFS/ME) is poorly understood. Simplified medical models tend to neglect the complexity of illness, contributing to a terrain of uncertainty, dilemmas and predicaments. However, despite pessimistic pictures of no cure and poor prognosis, some patients recover.

This study's purpose is to provide insight into people's experiences of suffering and recovery from very severe CFS/ME and illuminate understanding of how and why changes became possible.

Fourteen former patients were interviewed about their experiences of returning to health. A narrative analysis was undertaken to explore participants' experiences and understandings. We present the result through one participant's story.

The analysis yielded a common plotline with a distinct turning point. Participants went through a profound narrative shift, change in mindset and subsequent long-time work to actively pursue their own healing. Their narrative understandings of being helpless victims of disease were replaced by a more complex view of causality and illness and a new sense of self-agency developed.

We discuss the illness narratives in relation to the disease model and its shortcomings, the different voices dominating the stories at different times in a clinically, conceptually, and emotionally challenging area.

Post-exertional malaise (PEM) is considered a hallmark characteristic of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). This may also apply to subgroups of patients with long COVID-induced ME/CFS. However, it is uncertain to what extent PEM is acknowledged in routine specialist healthcare for ME/CFS patients, and how this affects patient outcomes.

This study aims to evaluate to what extent ME/CFS patients experienced focus on PEM in specialist healthcare practice and its significance for outcome and care quality.

Data from two online cross-sectional surveys covering specialist healthcare services for ME/CFS patients at rehabilitation institutes in Norway and two regional hospitals, respectively, were analyzed. Evaluations of 788 rehabilitation stays, 86 hospital consultations, and 89 hospital interventions were included. Logistic regression models and Mann-Whitney U-tests were used to quantify the impact of addressing PEM on health and functioning, care satisfaction, or benefit. Spearman's rank correlation and Cronbach's alpha of focus on PEM with the respondents' perception of healthcare providers' knowledge, symptom acknowledgment, and suitability of intervention were assessed as measures for care quality and their internal consistency, respectively.

PEM was addressed in 48% of the rehabilitation stays, 43% of the consultations, and 65% of the hospital interventions. Failure to address PEM roughly doubled the risk of health deterioration, following rehabilitation (OR = 0.39, 95% CI 0.29-0.52; 40.1% vs. 63.2% P = <0.001) and hospital intervention (OR = 0.34, 95% CI 0.13-0.89; 22.4% vs. 45.2%, p = 0.026). The focus on PEM (PEM-focus) during the clinical contact was associated with significantly higher scores on patients' rated care satisfaction and benefit of both consultation and intervention. Furthermore, addressing PEM was (inter)related to positive views about healthcare providers' level of knowledge of ME/CFS, their acknowledgment of symptoms, obtained knowledge, and the perceived suitability of intervention (Cronbach's alpha ≥0.80).

PEM is still frequently not acknowledged in specialist healthcare practice for ME/CFS patients in Norway. Not addressing PEM substantially increased the probability of a decline in health and functioning following the intervention and was strongly associated with reduced perceived care quality, satisfaction, and benefit. These findings may be related to the applied explanatory models for ME/CFS and are most likely of relevance to long COVID.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a poorly understood chronic illness with many case definitions that disagree on key symptoms, including hypersensitivities to noise and lights. The aim of the current study was to understand the prevalence rates and characteristics of these symptoms amongst people with ME/CFS and to compare them to people with another chronic illness, multiple sclerosis (MS). International datasets consisting of 2,240 people with either ME/CFS or MS have completed the DePaul Symptom Questionnaire (DSQ) and the Short Form Health Survey Questionnaire (SF-36). Hypersensitivities to noise and lights were indicated from items on the DSQ, and participants were analyzed against DSQ and SF-36 subscales through a multivariate analysis of covariance. There were significantly higher percentages of people with hypersensitivities in the ME/CFS sample compared to the MS sample. Regardless of illness, participants that exhibited both hypersensitivities reported greater symptomology than those without hypersensitivities. Healthcare providers and researchers should consider these symptoms when developing treatment plans and evaluating ME/CFS case diagnostic criteria.

Public health and welfare systems request documentation on approaches to diagnose, treat, and manage myalgic encephalomyelitis and assess disability-benefit conditions. Our objective is to document ME patients' experiences with services/interventions and assess differences between those meeting different diagnostic criteria, importantly the impact of post-exertional malaise. We surveyed 660 fatigue patients in Norway using respondent-driven sampling and applied validated DePaul University algorithms to estimate Canadian and Fukuda criteria proxies. Patients on average perceived most interventions as having low-to-negative health effects. Responses differed significantly between sub-groups for some key interventions. The PEM score was strongly associated with the experience of most interventions. Better designed and targeted interventions are needed to prevent harm to the patient group. The PEM score appears to be a strong determinant and adequate tool for assessing patient tolerance for certain interventions. There is no known treatment for ME, and "do-no-harm" should be a guiding principle in all practice.

Psychometric validation of the Multidimensional Chronic Asthenia Scale (MCAS) was conducted in order to provide an effective tool for assessing the health-related quality of life of French-speaking patients with chronic asthenia (CA).

Items resulting from the initial formulation of the self-reported MCAS (along with other materials) were completed by French-speaking volunteers with inactive or active inflammatory bowel disease (IBD-I vs. IBD-A) or chronic fatigue syndrome (CFS). Responses from 621 participants (180 patients with IBD-A, 172 with IBD-I, 269 with CFS) collected in a single online survey were divided into three subsamples to test the construct validity of the MCAS (Step 1, N = 240), to confirm its factorial structure (Step 2, N = 204) and to explore its convergent-discriminant validity with the Fatigue Symptoms Inventory (FSI) and revised Piper Fatigue Scale (r-PFS, Step 3, N = 177).

Steps 1 and 2 showed that, as expected, MCAS has four dimensions: feeling of constraint (FoC), physical (PC), life (LC) and interpersonal consequences (IC), which are also related to the duration of CA (i.e., the longer it lasts, the more the dimensions are impacted). The results further showed that the MCAS is sensitive enough to capture between-group differences, with the CFS group being the most impaired, followed by IBD-A and IBD-I. While convergent-discriminant validity between the 4 factors of MCAS and FSI and r-PFS, respectively, was satisfactory overall, Step 3 also pointed to some limitations that call for future research (e.g., shared variances between the PC and IC dimensions of MCAS and behavioral dimension of r-PFS).

Despite these limitations, the MCAS clearly constitutes a promising tool for measuring quantitative differences (i.e., severity/intensity) in CA associated with various diseases, but also, and importantly, the clinically important differences in domains of its expression (i.e., qualitative differences).

In the previous study, whole-body cryotherapy (WBC)+static stretching (SS) has been shown to reduce the severity of some symptoms in Chronic Fatigue Syndrome (CFS) noted just after the therapy. Here we consider the effects of treatment and explore the sustainability of symptom improvements at four weeks (one-month) follow-up. Twenty-two CFS patients were assessed one month after WBC + SS programme. Parameters related to fatigue (Chalder Fatigue Questionnaire (CFQ), Fatigue Impact Scale (FIS), Fatigue Severity Scale (FSS)), cognitive function (Trial Making test part A and B (TMT A and TMT B and its difference (TMT B-A)), Coding) hemodynamic, aortic stiffness (aortic systolic blood pressure (sBP aortic)) and autonomic nervous system functioning were measured. TMT A, TMT B, TMT B-A and Coding improved at one month after the WBC + SS programme. WBC + SS had a significant effect on the increase in sympathetic nervous system activity in rest. WBC + SS had a significant, positive chronotropic effect on the cardiac muscle. Peripheral and aortic systolic blood pressure decreased one month after WBC + SS in comparison to before. Effects of WBC + SS on reduction of fatigue, indicators of aortic stiffness and symptoms severity related to autonomic nervous system disturbance and improvement in cognitive function were maintained at one month. However, improvement in all three fatigue scales (CFQ, FIS and FSS) was noted in 17 of 22 patients. In addition, ten patients were treated initially but they were not assessed at 4 weeks, and are thus not included in the 22 patients who were examined on follow-up. The overall effects of WBC + SS noted at one month post-treatment should be interpreted with caution.

People with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) experience core symptoms of post-exertional malaise, unrefreshing sleep, and cognitive impairment. Despite numbering 0.2-0.4% of the population, no laboratory test is available for their diagnosis, no effective therapy exists for their treatment, and no scientific breakthrough regarding pathogenesis has been made. It remains unknown, despite decades of small-scale studies, whether individuals experience different types of ME/CFS separated by onset-type, sex or age.

DecodeME is a large population-based study of ME/CFS that recruited 17,074 participants in the first 3 months following full launch. Detailed questionnaire responses from UK-based participants who all reported being diagnosed with ME/CFS by a health professional provided an unparalleled opportunity to investigate, using logistic regression, whether ME/CFS severity or onset type is significantly associated with sex, age, illness duration, comorbid conditions or symptoms.

The well-established sex-bias among ME/CFS patients is evident in the initial DecodeME cohort: 83.5% of participants were females. What was not known previously was that females tend to have more comorbidities than males. Moreover, being female, being older and being over 10 years from ME/CFS onset are significantly associated with greater severity. Five different ME/CFS onset types were examined in the self-reported data: those with ME/CFS onset (i) after glandular fever (infectious mononucleosis); (ii) after COVID-19 infection; (iii) after other infections; (iv) without an infection at onset; and, (v) where the occurrence of an infection at or preceding onset is not known. Among other findings, ME/CFS onset with unknown infection status was significantly associated with active fibromyalgia.

DecodeME participants differ in symptoms, comorbid conditions and/or illness severity when stratified by their sex-at-birth and/or infection around the time of ME/CFS onset.

People with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) experience core symptoms of post-exertional malaise, unrefreshing sleep, and cognitive impairment. Despite numbering 0.2-0.4% of the population, no laboratory test is available for their diagnosis, no effective therapy exists for their treatment, and no scientific breakthrough regarding pathogenesis has been made. It remains unknown, despite decades of small-scale studies, whether individuals experience different types of ME/CFS separated by onset-type, sex or age.

DecodeME is a large population-based study of ME/CFS that recruited 17,074 participants in the first 3 months following full launch. Detailed questionnaire responses from UK-based participants who all reported being diagnosed with ME/CFS by a health professional provided an unparalleled opportunity to investigate, using logistic regression, whether ME/CFS severity or onset type is significantly associated with sex, age, illness duration, comorbid conditions or symptoms.

The well-established sex-bias among ME/CFS patients is evident in the initial DecodeME cohort: 83.5% of participants were females. What was not known previously was that females tend to have more comorbidities than males. Moreover, being female, being older and being over 10 years from ME/CFS onset are significantly associated with greater severity. Five different ME/CFS onset types were examined in the self-reported data: those with ME/CFS onset (i) after glandular fever (infectious mononucleosis); (ii) after COVID-19 infection; (iii) after other infections; (iv) without an infection at onset; and, (v) where the occurrence of an infection at or preceding onset is not known. Among other findings, ME/CFS onset with unknown infection status was significantly associated with active fibromyalgia.

DecodeME participants differ in symptoms, comorbid conditions and/or illness severity when stratified by their sex-at-birth and/or infection around the time of ME/CFS onset.

Limited published data suggests that absence of uplifts (minor pleasant events) is associated with clinical worsening in patients with chronic fatigue syndrome (CFS). The current study aimed to assess the relation of illness worsening to the trajectories of social and non-social uplifts and hassles in a six-month prospective study in CFS.

Participants were primarily in their 40s, female, white, and ill for over a decade. All participants (N = 128) met criteria for CFS. The interview-based global impression of change rating was used to classify individual outcomes as improved, unchanged, or worsened at six- month follow-up. Uplifts and hassles, both social and non-social, were assessed with the Combined Hassles and Uplifts Scale (CHUS). The CHUS was administered weekly in online diaries over six months. Linear mixed effect models were utilized to examine linear trends for hassles and uplifts.

No significant differences were found between the three global outcome groups for age, sex, or illness duration; however, work status was significantly lower for the non-improved groups (p < 0.001). Non-social hassles intensity showed an increasing slope for the worsened group (p = 0.03) and a decreasing slope (p = 0.05) for the improved group. For the worsened group, a downward trend was found for frequency of non-social (p = 0.01) uplifts.

Individuals with worsening as compared to improving illness in CFS show significantly different six-month trajectories for weekly hassles and a deficit in uplifts. This may have clinical implications for behavioral intervention. Trial registration ClinicalTrials.gov ID: NCT02948556.