Human Herpesvirus 6 Infection and Risk of Chronic Fatigue Syndrome: A Systematic Review and Meta-Analysis

Introduction: Chronic fatigue syndrome (CFS) is a neurological disease that is accompanied by excessive fatigue or tiredness. There are several reports confirming the association between human herpesvirus 6 (HHV-6) infection and CFS illness. This systematic review and meta-analysis was performed to integrate the information of published studies with regard to this association until May 2021. Methods: The literature search was based on keywords including "chronic fatigue syndrome and HHV 6, " "chronic fatigue syndrome and HHV-6, " "chronic fatigue syndrome and HHV6, " "chronic fatigue syndrome and Herpes virus 6, " and "chronic fatigue syndrome and Herpesvirus6 " in MEDLINE (PubMed), Web of Science, and EMBASE. Results: The literature search identified 17 studies to be included in the systematic review and 11 studies in meta-analysis. The symmetry funnel plot and Egger's test (p value = 0.2) identified no publication bias among studies. Moreover, the low level of I-2 revealed homogeneity across studies. Discussion: In conclusion, the association between the HHV-6 infection and CFS incidence was substantiated. However, the results of this study also suggest that further comprehensive studies are needed to solidify the association between HHV-6 and CFS. Future studies should consider additional factors that may have affected the significance of such a correlation. (c) 2021 The Author(s) Published by S. Karger AG, Basel