Review Evaluation of viral infection as an etiology of ME/CFS: a systematic review and meta-analysis 2023, Hwang et al

Abstract
Background

Myalgic encephalitis/chronic fatigue syndrome (ME/CFS) is a long-term disabling illness without a medically explained cause. Recently during COVID-19 pandemic, many studies have confirmed the symptoms similar to ME/CFS in the recovered individuals. To investigate the virus-related etiopathogenesis of ME/CFS, we conducted a systematic assessment of viral infection frequency in ME/CFS patients.

Methods
We conducted a comprehensive search of PubMed and the Cochrane Library from their inception through December 31, 2022, using selection criteria of viral infection prevalence in ME/CFS patients and controls. Subsequently, we performed a meta-analysis to assess the extent of viral infections' contribution to ME/CFS by comparing the odds ratio between ME/CFS patients and controls (healthy and/or diseased).

Results
Finally, 64 studies met our eligibility criteria regarding 18 species of viruses, including a total of 4971 ME/CFS patients and 9221 control subjects. The participants included healthy subjects and individuals with one of 10 diseases, such as multiple sclerosis or fibromyalgia. Two DNA viruses (human herpes virus (HHV)-7 and parvovirus B19, including their co-infection) and 3 RNA viruses (borna disease virus (BDV), enterovirus and coxsackie B virus) showed odds ratios greater than 2.0 compared with healthy and/or diseased subjects. Specifically, BDV exceeded the cutoff with an odds ratio of ≥ 3.47 (indicating a "moderate association" by Cohen’s d test) compared to both healthy and diseased controls.

Conclusion
This study comprehensively evaluated the risk of viral infections associated with ME/CFS, and identified BDV. These results provide valuable reference data for future studies investigating the role of viruses in the causation of ME/CFS.


https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-04635-0

 

That could just indicate that there's a correlation between immune system (dys)function and ME, which in turn could make them more susceptible to viral infection. If they did a similar study about bacterial or fungal infections, they might find similar correlations.

 

ME Research UK

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Although a number of different viruses – such as those that cause the common cold (enteroviruses) and others which lead to illnesses including glandular fever (human herpes viruses) – have been linked to ME/CFS, it remains unclear whether they may lead to the development of the disease. A recent study set out to review existing research, and explore what it can tell us about viruses as a potential cause of ME/CFS.
Read more: https://www.meresearch.org.uk/do-viruses-cause-me-cfs-what-does-the-evidence-say