Tag: outbreaks

Are enteroviruses behind mysterious outbreaks of chronic fatigue syndrome?

Chronic fatigue syndrome is a long-term illness with a wide range of symptoms, no known treatment, and undetermined origins. However, with as many as 65m people across the world living with the illness, researchers continue to search for answers.

Now, Prof Maureen Hanson of Cornell University discusses how she and graduate student James O’Neal searched through the research archives to see whether a genus of RNA viruses called enteroviruses are the most likely culprits and whether the findings have implications in future ‘long Covid’ research.

Like SARS-CoV-2, which causes Covid-19, viruses, enteroviruses (EVs) are RNA viruses that can lead to cause serious illness and death. One type of EV causes poliomyelitis, which is now largely conquered through near-universal vaccination.

But no vaccine exists against many other types of EVs, which are free to circulate widely. Indeed, the Centers for Disease Control and Prevention estimates between 10m-15m enteroviral infections occur each year in the US.

EVs have long been suspected as causal agents in outbreaks of an illness that is now usually named ME/CFS (myalgic encephalomyelitis/chronic fatigue syndrome). Outbreaks have been documented since the turn of the previous century and may have occurred earlier.

Many are unaware that ME/CFS can occur in epidemic form. The pathogen(s) inciting most of these outbreaks remain unidentified. One reason for this lamentable situation is that earlier virus identification technology was not as powerful as today’s methods.

Consider how quickly the complete sequence of SARS-CoV-2 was obtained not long after a new illness arose. But another reason that ME/CFS triggers are not known is the existing technology was not deployed to identify the agents causing multiple outbreaks in the mid-1980s. The failure of federal agencies to nor investigate these outbreaks, often dismissed as hysteria or unimportant, is well documented in investigative journalist Hillary Johnson’s Osler’s Web.

Read the rest of this article HERE.

Source: Frontiers Science News, August 12, 2o21. https://blog.frontiersin.org/2021/08/12/chronic-fatigue-syndrome-viruses-maureen-hanson-cornell-university/

The Enterovirus Theory of Disease Etiology in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Critical Review

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex, multi-system disease whose etiological basis has not been established. Enteroviruses (EVs) as a cause of ME/CFS have sometimes been proposed, as they are known agents of acute respiratory and gastrointestinal infections that may persist in secondary infection sites, including the central nervous system, muscle, and heart. To date, the body of research that has investigated enterovirus infections in relation to ME/CFS supports an increased prevalence of chronic or persistent enteroviral infections in ME/CFS patient cohorts than in healthy individuals. Nevertheless, inconsistent results have fueled a decline in related studies over the past two decades.

This review covers the aspects of ME/CFS pathophysiology that are consistent with a chronic enterovirus infection and critically reviews methodologies and approaches used in past EV-related ME/CFS studies. We describe the prior sample types that were interrogated, the methods used and the limitations to the approaches that were chosen. We conclude that there is considerable evidence that prior outbreaks of ME/CFS were caused by one or more enterovirus groups. Furthermore, we find that the methods used in prior studies were inadequate to rule out the presence of chronic enteroviral infections in individuals with ME/CFS. Given the possibility that such infections could be contributing to morbidity and preventing recovery, further studies of appropriate biological samples with the latest molecular methods are urgently needed.

Source: O’Neal AJ, Hanson MR. The Enterovirus Theory of Disease Etiology in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Critical Review. Front Med (Lausanne). 2021 Jun 18;8:688486. doi: 10.3389/fmed.2021.688486. PMID: 34222292; PMCID: PMC8253308. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8253308/  (Full text)

Chronic fatigue following infection by Coxiella burnetii (Q fever): ten-year follow-up of the 1989 UK outbreak cohort

Abstract:

BACKGROUND: Some patients exposed to Q fever (Coxiella burnetii infection) may develop chronic fatigue.

AIM: To determine whether subjects involved in the West Midlands Q fever outbreak of 1989 had increased fatigue, compared to non-exposed controls, 10 years after exposure.

DESIGN: Matched cohort study comparing cases to age-, sex- and smoking-history-matched controls not exposed to Q fever.

METHODS: A postal questionnaire was sent to subjects at home, followed by further assessment in hospital, including a physical examination and blood tests.

RESULTS: Of 108 Q-exposed subjects, 70 (64.8%) had fatigue, 37 idiopathic chronic fatigue (ICF) (34.3%), vs. 29/80 (36.3%) and 12 (15.0%), respectively, in controls. In 77 matched pairs, fatigue was commoner in Q-exposed subjects than in controls: 50 (64.9%) vs. 27 (35.1%), p<0.0001. ICF was found in 25 (32.5%) of Q-exposed patients and 11(14.3%) of controls (p=0.01). There were 36 (46.8%) GHQ cases in Q-exposed subjects, vs. 18 (23.4%) controls (p=0.004). A matched analysis of those more intensively studied showed fatigue in 48 (66.7%) Q-exposed patients and 25 (34.7%) controls, (p<0.0001), ICF in 25 (34.7%) Q-exposed and 10 (13.9%) controls (p=0.004), and chronic fatigue syndrome (CFS) in 14 (19.4%) Q-exposed patients and three (4.2%) controls (p=0.003). Thirty-four (47.2%) Q-exposed patients were GHQ cases compared to 17 (23.6%) controls (p=0.004).

DISCUSSION: Subjects who were exposed to Coxiella in 1989 had more fatigue than did controls, and some fulfilled the criteria for CFS. Whether this is due to ongoing antigen persistence or to the psychological effects of prolonged medical follow-up is uncertain.

Comment in: Q fever: still a mysterious disease. [QJM. 2002]

 

Source: Wildman MJ, Smith EG, Groves J, Beattie JM, Caul EO, Ayres JG. Chronic fatigue following infection by Coxiella burnetii (Q fever): ten-year follow-up of the 1989 UK outbreak cohort. QJM. 2002 Aug;95(8):527-38. http://qjmed.oxfordjournals.org/content/95/8/527.long (Full article)

 

Epidemiologic advances in chronic fatigue syndrome

Abstract:

Epidemiologic studies of chronic fatigue syndrome (CFS) have been hampered by the absence of a specific diagnostic test, but with increasing interest in this disorder there has been a greater understanding of the risk factors, illness patterns, and other aspects of this multisystem disorder.

Working case definitions have been developed for research purposes but they have continued to change over time and have not always been utilized precisely by various investigators. This has been a major factor in the widely varying estimates of prevalence rates, but two different studies using the same working definition and including a medical work-up have estimated the prevalence to be approximately 200/100,000. Clusters of CFS cases, which appear to be related to earlier reports of “epidemic neuromyasthenia”, have attracted considerable attention and appear to be well documented, although investigated with varying methodology and often with dissimilar case definitions.

Risk factors for cases occurring in clusters and sporadically appear to be similar, the most consistent ones being female gender and the co-existence of some form of stress, either physical or psychological. The prognosis of CFS is difficult to predict, although cases occurring as part of clusters appear to have a better prognosis as a group than sporadic cases, and those with an acute onset have a better prognosis than those with gradual onset.

It is highly unlikely that there is a single agent, infectious or noninfectious, that is responsible for more than a small proportion of CFS cases and, at the present time, the risk factors for developing CFS appear to lie more prominently in the host rather than the environment.

 

Source: Levine PH. Epidemiologic advances in chronic fatigue syndrome. J Psychiatr Res. 1997 Jan-Feb;31(1):7-18. http://www.ncbi.nlm.nih.gov/pubmed/9201643

 

Postviral fatigue syndrome

Abstract:

The post-viral fatigue syndrome occurs sporadically and in local outbreaks (Los Angeles, Akureyri, Royal Free Hospital). The clinical picture is marked by long-lasting muscular fatigue directly following an acute infection. Other conditions associated with pronounced fatigue must be excluded. The diagnostic criteria set up by Centers for Disease Control (CDC) are the ones most commonly used. Aetiology and pathogenesis are unknown. Coxsackie B-virus seems to be associated with some cases at least. Immunological and endocrinological aberration, morphological changes in mitochondria and reduced cerebral blood perfusion have been demonstrated in some patients. There is no specific therapy. It is important for the patient that the symptoms be accepted by the doctor and society in general.

Comment in: [Chronic fatigue syndrome]. [Tidsskr Nor Laegeforen. 1995]

 

Source: Haukenes G, Aarli JA. Postviral fatigue syndrome. Tidsskr Nor Laegeforen. 1995 Oct 10;115(24):3017-22. [Article in Norwegian] http://www.ncbi.nlm.nih.gov/pubmed/7570529

 

Chronic fatigue syndrome–cases in the Kanebo Memorial Hospital

Abstract:

In our hospital, 134 patients (28 male, 106 female, 10-82 years of age) were diagnosed as having chronic fatigue syndrome (CFS). Some patients had mild elevation of antibodies against Epstein-Barr Virus and immunologic abnormalities (natural killer cell dysfunction and high rates of skin reactivity to house dust, pollen, drugs and common food). In the patients with immunologic abnormalities, we found decreases in serum concentrations of arachidonic acid and dihomogamma-linolenic acid. A Kampo medicine, Ren-Shen-Yang-Rong-Tang was used in the management of 134 patients and 98 patients returned to work or school.

 

Source: Ogawa R, Toyama S, Matsumoto H. Chronic fatigue syndrome–cases in the Kanebo Memorial Hospital. Nihon Rinsho. 1992 Nov;50(11):2648-52. [Article in Japanese] http://www.ncbi.nlm.nih.gov/pubmed/1337561

 

Chronic fatigue syndrome–study of 51 cases treated at the Second Tokyo National Hospital

Abstract:

Fifty-one patients with chronic fatigue syndrome (CFS) were studied. Tender points, which are a characteristic clinical feature of fibromyalgia, were found in all but two of the patients at 11.4 points (mean) per patient. IgG antibody titers to EB virus viral capsid antigen were more elevated in the CFS patient group compared to that of the control (p < 0.0015). IgG antibody titers to HHV-6 were not higher in the patient group. NK cell activity was not more decreased in the patient group, whereas, the mean number of NK cells was lower (p < 0.005) in the patient group, when CD57 was used as the NK cell marker. Viral infections and/or disorders in cellular immunity may be important factors in the pathogenesis of CFS.

 

Source: Nishikai M. Chronic fatigue syndrome–study of 51 cases treated at the Second Tokyo National Hospital. Nihon Rinsho. 1992 Nov;50(11):2641-7. [Article in Japanese] http://www.ncbi.nlm.nih.gov/pubmed/1337560

 

Chronic fatigue syndrome–51 cases in the Jikei University School of Medicine

Abstract:

Between April 1991 and August 1992, we diagnosed 51 cases of CFS who met definition of CFS designated by CDC, 1988. They are 41 female and 11 male, and 78% are women. At first visit, their ages are ranged from 16 to 64 years old, and approximately 45% is 20 to 30 years old.

In periods of illness from onset, 39.2% of the patients are in period of 6 month to 1 year, 19.6% within 2 years, and 15.6% within 3 years, respectively. The sufferer who have symptoms of CFS over 10 years long are in 6 cases.

Most of patients have already been examined by many other clinics and hospitals. They have been told as no abnormal medical condition, or often as neurosis, depressive state and autonomous imbalance etc.

Interesting things are trigger of CFS. 77.5% of patients have onset of flu-like symptom, including 5 cases of acute infectious mononucleosis. In many female patients, symptoms of CFS begun after hard work in addition to psychological factors. Specific laboratory results are not shown in CBC, urinalysis, biochemical studies and inflammatory markers. 6 cases have positive Rheumatoid factor and positive ANF are shown in 16 cases (31.3%).

Specific patterns of anti EBV antibodies are not shown. Lymphocyte subsets used by monoclonal antibodies are not specific. At the present, prognosis is good and 56.8% of CFS patients are generally improved. For severe cases, NSAID, Sulpiride, Amitryptiline and minor tranquilizer are used.

 

Source: Hashimoto N, Kuraishi Y, Yokose T, Tajima N, Mochio S, Shimizu M, Yokoyama J, Kobayashi N, Nohara A, Taniguchi I, et al. Chronic fatigue syndrome–51 cases in the Jikei University School of Medicine. Nihon Rinsho. 1992 Nov;50(11):2653-64. [Article in Japanese] http://www.ncbi.nlm.nih.gov/pubmed/1287241

 

Does chronic fatigue syndrome predispose to non-Hodgkin’s lymphoma?

Abstract:

Chronic fatigue syndrome, an illness that frequently is associated with abnormalities of cellular immunity, has been reported anecdotally to be associated with an increased incidence of lymphoid hyperplasia and malignancy.

This report describes an initial analysis of population-based cancer incidence data in Nevada, focusing on the patterns of non-Hodgkin’s lymphoma prior to and subsequent to well described, documented outbreaks of chronic fatigue syndrome during 1984-1986. In a study of time trends in four age groups, the observed time trends were consistent with the national trends reported in the Surveillance, Epidemiology, and End Results Program.

No statistically significant increase attributable to the chronic fatigue syndrome outbreak was identified at the state level. Additional studies are in progress analyzing the data at the country level, reviewing patterns in other malignancies, and continuing to monitor the cancer patterns over subsequent years.

 

Source: Levine PH, Peterson D, McNamee FL, O’Brien K, Gridley G, Hagerty M, Brady J, Fears T, Atherton M, Hoover R. Does chronic fatigue syndrome predispose to non-Hodgkin’s lymphoma? Cancer Res. 1992 Oct 1;52(19 Suppl):5516s-5518s; discussion 5518s-5521s. http://www.ncbi.nlm.nih.gov/pubmed/1394166

 

Clinical, epidemiologic, and virologic studies in four clusters of the chronic fatigue syndrome

Abstract:

BACKGROUND: The purpose of this study is to provide a case definition of chronic fatigue syndrome in an outbreak occurring in the Nevada-California region to evaluate candidate etiologic agents and observe the natural history of the illness.

METHODS: Patients diagnosed as having chronic fatigue syndrome were studied by repeated interviews, questionnaires, and blood collection over a 3-year period. Serum samples were tested for antibodies to Epstein-Barr virus, human herpesvirus-6, and human T-lymphotropic viruses I and II. Leukocytes from typical cases were also assayed for human T-lymphotropic viruses I and II.

RESULTS: Cases were defined as persons who had: (1) severe persistent fatigue following an acute illness appearing in an individual with no previous physical or psychological symptoms; (2) presenting signs and symptoms of an acute infection; (3) severe and persistent headache and/or myalgias; and (4) abrupt change in cognitive function or the appearance of a new mood disorder. After 3 years of follow-up, almost all study subjects were able to return to pre-illness activity. None of the viruses evaluated–human T-lymphotropic viruses I and II, Epstein-Barr virus, or human herpesvirus-6–could be etiologically linked to these outbreaks.

CONCLUSION: Clinical features of outbreaks of chronic fatigue syndrome differ sufficiently to suggest different etiologic agents. Giardiasis appears to have precipitated one of the four clusters in this study but the cause(s) of the other three outbreaks is as yet uncertain. The overall prognosis ofchronic fatigue syndrome is usually favorable.

Comment in: Human herpesvirus type 6 and chronic fatigue syndrome. [Arch Intern Med. 1993]

 

Source: Levine PH, Jacobson S, Pocinki AG, Cheney P, Peterson D, Connelly RR, Weil R, Robinson SM, Ablashi DV, Salahuddin SZ, et al. Clinical, epidemiologic, and virologic studies in four clusters of the chronic fatigue syndrome. Arch Intern Med. 1992 Aug;152(8):1611-6. http://www.ncbi.nlm.nih.gov/pubmed/1323246