The lack of clear treatment options currently shapes work on long-term effects.
There is no approved standard therapy, and most recommendations are based on limited evidence.
According to the researchers behind a major review article in Frontiers of Medicine, this is a direct consequence of the disease affecting multiple organ systems and not following a uniform course.
This makes both clinical practice and research design difficult.
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Uncertain treatment
Health authorities and clinicians therefore have to work with provisional solutions.
Rehabilitation, pacing of daily activities, and symptom-based treatment are widely used, even though the supporting evidence varies.
The researchers behind the review article point out that early antiviral treatment during the acute infection may reduce the risk of long-term consequences, but the effect is modest and not consistent across studies.
Biological hypotheses
At the biological level, research is working with several parallel explanations.
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One central hypothesis is that persistent inflammation plays a decisive role, measured, among other things, by elevated inflammatory markers.
In addition, findings of microscopic blood clots may affect the function of blood vessels.
According to the researchers, disturbances in immune regulation, gut microbiota, and cellular energy production may also contribute.
However, none of these mechanisms alone can explain the full disease picture.
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Scope and consequences
Long-term effects are estimated to affect a very large number of people globally, but precise figures depend on definitions and methods of assessment.
It is precisely this variation in international criteria that makes comparison difficult and contributes to uncertainty in health systems.
The researchers believe that long-term effects should be treated as a complex, chronic condition until more robust data are available.
Sources: Science Daily, and Frontiers of Medicine.
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