Tag: risk factors

Predisposing and Precipitating Factors in Epstein–Barr Virus-Caused Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Long COVID following SARS-CoV-2 and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) following infectious mononucleosis (IM) are two examples of post-viral syndromes. The identification of risk factors predisposing patients to developing and maintaining post-infectious syndromes may help uncover their underlying mechanisms.
The majority of patients with ME/CFS report infectious illnesses before the onset of ME/CFS, with 30% of cases of ME/CFS due to IM caused by the Epstein–Barr virus. After developing IM, one study found 11% of adults had ME/CFS at 6 months and 9% had ME/CFS at 1 year. Another study of adolescents found 13% and 7% with ME/CFS at 6 and 12 months following IM, respectively. However, it is unclear which variables are potential risk factors contributing to the development and maintenance of ME/CFS following IM, because few prospective studies have collected baseline data before the onset of the triggering illness.
The current article provides an overview of a study that included pre-illness predictors of ME/CFS development following IM in a diverse group of college students who were enrolled before the onset of IM. Our data set included an ethnically and sociodemographically diverse group of young adult students, and we were able to longitudinally follow these youths over time to better understand the risk factors associated with the pathophysiology of ME/CFS.
General screens of health and psychological well-being, as well as blood samples, were obtained at three stages of the study (Stage 1—Baseline—when the students were well, at least 6 weeks before the student developed IM; Stage 2—within 6 weeks following the diagnosis of IM, and Stage 3—six months after IM, when they had either developed ME/CFS or recovered). We focused on the risk factors for new cases of ME/CFS following IM and found factors both at baseline (Stage 1) and at the time of IM (Stage 2) that predicted nonrecovery. We are now collecting seven-year follow-up data on this sample, as well as including cases of long COVID. The lessons learned in this prospective study are reviewed.
Source: Jason LA, Katz BZ. Predisposing and Precipitating Factors in Epstein–Barr Virus-Caused Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Microorganisms. 2025; 13(4):702. https://doi.org/10.3390/microorganisms13040702 https://www.mdpi.com/2076-2607/13/4/702 (Full text)

mTORC1 syndrome (TorS): unifying paradigm for PASC, ME/CFS and PAIS

Abstract:

Post-acute SarS-Cov2 (PASC), Myalgia encephalomyelitis/Chronic fatigue syndrome (ME/CFS) and Post-acute infection syndrome (PAIS) consist of chronic post-acute infectious syndromes, sharing exhaustive fatigue, post exertional malaise, intermittent pain, postural tachycardia and neuro-cognitive-psychiatric dysfunction. However, the concerned shared pathophysiology is still unresolved in terms of upstream drivers and transducers. Also, risk factors which may determine vulnerability/progression to the chronic phase still remain to be defined.

In lack of drivers and a cohesive pathophysiology, the concerned syndromes still remain unmet therapeutic needs. ‘mTORC1 Syndrome’ (TorS) implies an exhaustive disease entity driven by sustained hyper-activation of the mammalian target of rapamycin C1 (mTORC1), and resulting in a variety of disease aspects of the Metabolic Syndrome (MetS), non-alcoholic fatty liver disease, chronic obstructive pulmonary disease, some cancers, neurodegeneration and other [Bar-Tana in Trends Endocrinol Metab 34:135-145, 2023]. TorS may offer a cohesive insight of PASC, ME/CFS and PAIS drivers, pathophysiology, vulnerability and treatment options.

Source: Bar-Tana J. mTORC1 syndrome (TorS): unifying paradigm for PASC, ME/CFS and PAIS. J Transl Med. 2025 Mar 10;23(1):297. doi: 10.1186/s12967-025-06220-z. PMID: 40059164. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-025-06220-z (Full text)

Impact of COVID-19 on myalgic encephalomyelitis/chronic fatigue syndrome-like illness prevalence: A cross-sectional survey

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) can be triggered by infectious agents including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the impact of the coronavirus disease 2019 (COVID-19) pandemic on ME/CFS prevalence is not well characterized.

Methods: In this population-based cross-sectional study, we enrolled a stratified random sample of 9,825 adult participants in the Kaiser Permanente Northern California (KPNC) integrated health system from July to October 2022 to assess overall ME/CFS-like illness prevalence and the proportion that were identified following COVID-19 illness. We used medical record and survey data to estimate the prevalence of ME/CFS-like illness based on self-reported symptoms congruent with the 2015 Institute of Medicine ME/CFS criteria. History of COVID-19 was based on a positive SARS-CoV-2 nucleic acid amplification test or ICD-10 diagnosis code in the medical record, or self-report of prior COVID-19 on a survey.

Results: Of 2,745,374 adults in the eligible population, an estimated 45,892 (95% confidence interval [CI]: 32,869, 58,914) or 1.67% (CI 1.20%, 2.15%) had ME/CFS-like illness. Among those with ME/CFS-like illness, an estimated 14.12% (CI 3.64%, 24.6%) developed the illness after COVID-19. Among persons who had COVID-19, those with ME/CFS-like illness after COVID-19 were more likely to be unvaccinated and to have had COVID-19 before June 1, 2021. All persons with ME/CFS-like illness had significant impairment in physical, mental, emotional, social, and occupational functioning compared to persons without ME/CFS-like illness.

Conclusions: In a large, integrated health system, 1.67% of adults had ME/CFS-like illness and 14.12% of all persons with ME/CFS-like illness developed it after COVID-19. Though COVID-19 did not substantially increase ME/CFS-like illness in the KPNC population during the study time period, ME/CFS-like illness nevertheless affects a notable portion of this population and is consistent with estimates of ME/CFS prevalence in other populations. Additional attention is needed to improve awareness, diagnosis, and treatment of ME/CFS.

Source: Wood MS, Halmer N, Bertolli J, Amsden LB, Nugent JR, Lin JS, Rothrock G, Nadle J, Chai SJ, Cope JR, Champsi JH, Yang J, Unger ER, Skarbinski J; for STOP-ME/CFS and COVID-SELECT. Impact of COVID-19 on myalgic encephalomyelitis/chronic fatigue syndrome-like illness prevalence: A cross-sectional survey. PLoS One. 2024 Sep 18;19(9):e0309810. doi: 10.1371/journal.pone.0309810. PMID: 39292671; PMCID: PMC11410243. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11410243/ (Full text)

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome After SARS-CoV-2 Infection

Abstract:

Importance: Chronic symptoms reported following an infection with SARS-CoV-2, such as cognitive problems, overlap with symptoms included in the definition of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Objective: To evaluate the prevalence of ME/CFS-like illness subsequent to acute SARS-CoV-2 infection, changes in ME/CFS symptoms through 12 months of follow-up, and the association of ME/CFS symptoms with SARS-CoV-2 test results at the acute infection-like index illness.

Design, setting, and participants: This prospective, multisite, longitudinal cohort study (Innovative Support for Patients with SARS-CoV-2 Infections Registry [INSPIRE]) enrolled participants from December 11, 2020, to August 29, 2022. Participants were adults aged 18 to 64 years with acute symptoms suggestive of SARS-CoV-2 infection who received a US Food and Drug Administration-approved SARS-CoV-2 test at the time of illness and did not die or withdraw from the study by 3 months. Follow-up surveys were collected through February 28, 2023.

Exposure: COVID-19 status (positive vs negative) at enrollment.

Main outcome and measures: The main outcome was the weighted proportion of participants with ME/CFS-like illness based on the 2015 Institute of Medicine clinical case definition using self-reported symptoms.

Results: A total of 4378 participants were included in the study. Most were female (3226 [68.1%]). Mean (SD) age was 37.8 (11.8) years. The survey completion rates ranged from 38.7% (3613 of 4738 participants) to 76.3% (1835 of 4738) and decreased over time. The weighted proportion of participants identified with ME/CFS-like illness did not change significantly at 3 through 12 months of follow-up and was similar in the COVID-19-positive (range, 2.8%-3.7%) and COVID-19-negative (range, 3.1%-4.5%) groups. Adjusted analyses revealed no significant difference in the odds of ME/CFS-like illness at any time point between COVID-19-positive and COVID-19-negative individuals (marginal odds ratio range, 0.84 [95% CI, 0.42-1.67] to 1.18 [95% CI, 0.55-2.51]).

Conclusions and relevance: In this prospective cohort study, there was no evidence that the proportion of participants with ME/CFS-like illness differed between those infected with SARS-CoV-2 vs those without SARS-CoV-2 infection up to 12 months after infection. A 3% to 4% prevalence of ME/CFS-like illness after an acute infection-like index illness would impose a high societal burden given the millions of persons infected with SARS-CoV-2.

Source: Unger ER, Lin JS, Wisk LE, Yu H, L’Hommedieu M, Lavretsky H, Montoy JCC, Gottlieb MA, Rising KL, Gentile NL, Santangelo M, Venkatesh AK, Rodriguez RM, Hill MJ, Geyer RE, Kean ER, Saydah S, McDonald SA, Huebinger R, Idris AH, Dorney J, Hota B, Spatz ES, Stephens KA, Weinstein RA, Elmore JG; Innovative Support for Patients with SARS-CoV-2 Infections Registry (INSPIRE) Group. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome After SARS-CoV-2 Infection. JAMA Netw Open. 2024 Jul 1;7(7):e2423555. doi: 10.1001/jamanetworkopen.2024.23555. PMID: 39046739; PMCID: PMC11270135. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11270135/ (Full text)

Increased risk of chronic fatigue syndrome following pneumonia: A population-based Cohort study

Abstract:

Background: Chronic fatigue syndrome (CFS) has been linked to several conditions, including infections, immune system changes, or emotional stress. Our study aimed to assess the risk of CFS after a pneumonia diagnosis using data from National Health Insurance Research Database of Taiwan.

Methods: In this nested case-control study, we identified 2,000,000 adult patients from a nationwide population-based health insurance claims database spanning from January 1, 2000, to December 31, 2017. Each case diagnosed with a pathogenic infection was matched with a corresponding control using propensity scores. We excluded individuals under 20 years of age, those with a history of pathogenic infections before the index date, or those with more than one potential pathogen. To estimate hazard ratios (HR) and the adjusted hazard ratio (aHR) with their respective 95 % confidence intervals (CI), we applied univariable and multivariable Cox proportional hazard models. The multivariable analysis incorporated adjustments for age, sex, and comorbidity-related confounders.

Results: The relationship between infection and the subsequent risk of CFS was assessed using Cox proportional hazards regression analysis. The incidence density rates were 6.13 and 8.70 per 1000 person-years among the non-pulmonary infection and pulmonary infection populations, respectively (adjusted hazard ratio [HR] = 1.4, 95 % confidence interval [CI] 1.32-1.5). Patients infected with Pseudomonas, Klebsiella pneumoniae, Haemophilus influenzae, Streptococcus pneumoniae, and influenza virus exhibited a significantly higher risk of CFS than those without these pathogens (p < 0.05). Additionally, patients with pneumonia had a significantly increased risk of thromboembolism compare with control group (p < 0.05).

Source: Hsu HJ, Chang H, Lin CL, Yao WC, Hung CL, Pang SP, Kuo CF, Tsai SY. Increased risk of chronic fatigue syndrome following pneumonia: A population-based Cohort study. J Infect Public Health. 2024 Jul 14;17(8):102495. doi: 10.1016/j.jiph.2024.102495. Epub ahead of print. PMID: 39018725. https://www.sciencedirect.com/science/article/pii/S1876034124002296 (Full text)

Development of an expert system for the classification of myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a severe condition with an uncertain origin and a dismal prognosis. There is presently no precise diagnostic test for ME/CFS, and the diagnosis is determined primarily by the presence of certain symptoms. The current study presents an explainable artificial intelligence (XAI) integrated machine learning (ML) framework that identifies and classifies potential metabolic biomarkers of ME/CFS.

Metabolomic data from blood samples from 19 controls and 32 ME/CFS patients, all female, who were between age and body mass index (BMI) frequency-matched groups, were used to develop the XAI-based model. The dataset contained 832 metabolites, and after feature selection, the model was developed using only 50 metabolites, meaning less medical knowledge is required, thus reducing diagnostic costs and improving prognostic time. The computational method was developed using six different ML algorithms before and after feature selection. The final classification model was explained using the XAI approach, SHAP.

The best-performing classification model (XGBoost) achieved an area under the receiver operating characteristic curve (AUCROC) value of 98.85%. SHAP results showed that decreased levels of alpha-CEHC sulfate, hypoxanthine, and phenylacetylglutamine, as well as increased levels of N-delta-acetylornithine and oleoyl-linoloyl-glycerol (18:1/18:2)[2], increased the risk of ME/CFS. Besides the robustness of the methodology used, the results showed that the combination of ML and XAI could explain the biomarker prediction of ME/CFS and provided a first step toward establishing prognostic models for ME/CFS.

Source: Yagin FH, Shateri A, Nasiri H, Yagin B, Colak C, Alghannam AF. Development of an expert system for the classification of myalgic encephalomyelitis/chronic fatigue syndrome. PeerJ Comput Sci. 2024 Mar 20;10:e1857. doi: 10.7717/peerj-cs.1857. PMID: 38660205; PMCID: PMC11041999. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11041999/ (Full text)

The influence of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) family history on patients with ME/CFS

Abstract:

Aim: It is unclear if individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) with family histories of ME/CFS differ from those with ME/CFS without this family history. To explore this issue, quantitative data from patients with ME/CFS and controls were collected, and we examined those with and without family histories of ME/CFS.

Methods: The samples included 400 patients with ME/CFS, and a non-ME/CFS chronic illness control group of 241 patients with multiple sclerosis (MS) and 173 with post-polio syndrome (PPS).

Results: Confirming findings from prior studies, those with ME/CFS were more likely to have family members with ME/CFS than controls. We found family histories of ME/CFS were significantly higher (18%) among the ME/CFS group than the non-ME/CFS controls (3.9%). In addition, patients with ME/CFS who had family histories of ME/CFS were more likely to have gastrointestinal symptoms than those with ME/CFS without those family histories.

Conclusions: Given the recent reports of gastrointestinal difficulties among those with ME/CFS, our findings might represent one predisposing factor for the emergence of ME/CFS.
Source: Jason LA, Ngonmedje S. The influence of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) family history on patients with ME/CFS. Explor Med. 2024;5:185–92. https://doi.org/10.37349/emed.2024.00215 https://www.explorationpub.com/Journals/em/Article/1001215 (Full text)

Joint Flexibility and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome After Mononucleosis

Abstract:

Purpose: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic disease characterized by substantial fatigue, postexertional malaise, unrefreshing sleep, and orthostatic intolerance, among other symptoms. Specific risk factors for the development of ME/CFS have not been adequately characterized. It has been suggested that ME/CFS is a connective tissue disorder and that joint hyperflexibility is a risk factor for the development of ME/CFS.

Methods: The goal of this study was to examine whether joint hyperflexibility is a risk factor for the development of ME/CFS after infectious mononucleosis (IM). This study was part of a prospective cohort study. College students were studied for the development of IM and were followed up for the development of ME/CFS 6 months later. Participants in the cohort for the present study included 53 students who met criteria for ME/CFS 6 months after IM and 66 recovered control subjects who had modified Beighton scores (a measure of joint hyperflexibility) available.

Findings: No connection was found between joint hyperflexibility and the development of ME/CFS after IM. Differences in joint hyperflexibility (as measured by using the modified Beighton score) in the ME/CFS group and the control group were not statistically significant. Female subjects had significantly higher Beighton scores compared with male subjects.

Implication: After IM, no relationship was found between joint hyperflexibility and the development of ME/CFS.

Source: Poomkudy JT, Torres C, Jason LA, Fishbein J, Katz BZ. Joint Flexibility and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome After Mononucleosis. Clin Ther. 2024 Jan 18:S0149-2918(24)00006-7. doi: 10.1016/j.clinthera.2023.12.011. Epub ahead of print. PMID: 38242746.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in Adults: United States, 2021-2022

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex, multisystem illness characterized by activity-limiting fatigue, worsening of symptoms after activity, and other symptoms (1). It affects all age, sex, and racial and ethnic groups and costs the U.S. economy about $18-$51 billion annually (2-5). This report describes the percentage of adults who had ME/CFS at the time of interview by selected demographic and geographic characteristics based on data from the 2021-2022 National Health Interview Survey (NHIS).

Source: Vahratian A, Lin JS, Bertolli J, Unger ER. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in Adults: United States, 2021-2022. NCHS Data Brief. 2023 Dec;(488):1-8. PMID: 38085820. https://www.cdc.gov/nchs//data/databriefs/db488.pdf (Full text)

Increased risk of chronic fatigue syndrome following infection: a 17-year population-based cohort study

Abstract:

Background: Previous serological studies have indicated an association between viruses and atypical pathogens and Chronic Fatigue Syndrome (CFS). This study aims to investigate the correlation between infections from common pathogens, including typical bacteria, and the subsequent risk of developing CFS. The analysis is based on data from Taiwan’s National Health Insurance Research Database.

Methods: From 2000 to 2017, we included a total of 395,811 cases aged 20 years or older newly diagnosed with infection. The cases were matched 1:1 with controls using a propensity score and were followed up until diagnoses of CFS were made.

Results: The Cox proportional hazards regression analysis was used to estimate the relationship between infection and the subsequent risk of CFS. The incidence density rates among non-infection and infection population were 3.67 and 5.40 per 1000 person-years, respectively (adjusted hazard ratio [HR] = 1.5, with a 95% confidence interval [CI] 1.47-1.54). Patients infected with Varicella-zoster virus, Mycobacterium tuberculosis, Escherichia coli, Candida, Salmonella, Staphylococcus aureus and influenza virus had a significantly higher risk of CFS than those without these pathogens (p < 0.05). Patients taking doxycycline, azithromycin, moxifloxacin, levofloxacin, or ciprofloxacin had a significantly lower risk of CFS than patients in the corresponding control group (p < 0.05).

Conclusion: Our population-based retrospective cohort study found that infection with common pathogens, including bacteria, viruses, is associated with an increased risk of developing CFS.

Source: Chang H, Kuo CF, Yu TS, Ke LY, Hung CL, Tsai SY. Increased risk of chronic fatigue syndrome following infection: a 17-year population-based cohort study. J Transl Med. 2023 Nov 11;21(1):804. doi: 10.1186/s12967-023-04636-z. PMID: 37951920. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-04636-z (Full text)