From the Guidelines
Epstein-Barr virus (EB) is not a reliable marker for diagnosing Long COVID. While some studies have suggested a possible association between Epstein-Barr virus reactivation and Long COVID symptoms in certain patients, as noted in a 2023 review of long COVID published in Nature Reviews Microbiology 1, there is currently insufficient evidence to use EB as a definitive diagnostic marker. The relationship between EB and Long COVID is complex, with EB being extremely common in the general population and its reactivation potentially occurring during many different illnesses or periods of immune stress. Some researchers hypothesize that COVID-19 might trigger EB reactivation in some individuals, potentially contributing to persistent symptoms, but this mechanism is not well-established or consistent across all Long COVID cases, as also discussed in guidelines for the assessment and management of long COVID published in Clinical Microbiology and Infection in 2022 1. Current diagnostic approaches for Long COVID focus on symptom assessment, exclusion of alternative causes, and consideration of multiple biomarkers rather than relying on any single marker like EB virus. Key considerations in the diagnosis and management of long COVID include:
- Persistent symptoms following SARS-CoV-2 infection
- Exclusion of alternative causes for these symptoms
- Consideration of multiple biomarkers and not relying on a single marker
- Focus on improving quality of life, return to baseline physical activity, and return to work Given the lack of objective diagnostic criteria and evidence-based interventions for long COVID, as highlighted in the 2022 guidelines 1, a comprehensive and cautious approach is necessary, prioritizing the well-being and recovery of patients over reliance on any single diagnostic marker.
From the Research
Reliability of EB as a Marker for Long COVID
- The reliability of EB (Epstein-Barr virus) as a marker for long COVID is a topic of ongoing research, with some studies suggesting a potential link between EBV reactivation and long COVID symptoms 2, 3.
- A study published in 2021 found that 66.7% of long COVID subjects were positive for EBV reactivation, compared to 10% of control subjects, suggesting a significant association between EBV reactivation and long COVID symptoms 2.
- Another study published in 2023 found that COVID-19 patients experienced increased reactivation of EBV compared to COVID-negative patients, with 27.1% of EBV reactivations occurring in the COVID-positive group 3.
- However, other studies have noted that the etiology of long COVID remains unclear, and that many pathophysiological pathways may be involved, including viral persistence, chronic inflammation, and immune dysregulation 4, 5.
- A review of serological markers for long COVID found that there was no strong evidence to support any difference in serological markers, including EBV, between groups with and without persisting symptoms 6.
Limitations and Challenges
- The studies on EBV reactivation and long COVID have several limitations, including small sample sizes and variability in study design and methodology 6, 2, 3.
- The lack of standardized reporting practices and the heterogeneity of long COVID symptoms make it challenging to draw firm conclusions about the reliability of EB as a marker for long COVID 4, 6.
- Further research is needed to fully understand the relationship between EBV reactivation and long COVID symptoms, and to develop reliable biomarkers for the diagnosis and prognosis of long COVID 4, 5.