A new study indicates that COVID-19 infections can awaken long-dormant viruses residing within the bodies of individuals, a phenomenon that may contribute to the understanding of long COVID. Researchers at the University of Texas at Austin found that this viral reactivation can occur even in people who were healthy prior to their COVID-19 illness.
The study observed patients who had contracted COVID-19, none of whom had been vaccinated against the virus at the time. Participants were categorized based on the severity of their illness, ranging from mild cases to those who died within 28 days of hospitalization. Samples collected during hospitalization and for up to a year post-discharge were analyzed.
Investigators discovered that approximately half of the patients experienced the reactivation of at least one dormant virus during their COVID-19 illness. Among the reawakened pathogens were the Epstein-Barr virus, responsible for mononucleosis, and other viruses belonging to the herpes family. These viruses are known to remain in the body for extended periods and can re-emerge during times of stress or illness.
"This finding suggests that COVID-19 may not always act as a single viral infection and may disrupt the body’s internal ecosystem of dormant viruses," stated Dr. Cole Maguire, the study's lead author, in a press release. The reactivation was not confined to individuals with compromised immune systems, frequently appearing in those who had been healthy before contracting COVID-19.
Patients whose dormant infections resurfaced were observed to be more prone to severe illness, longer hospital stays, serious complications, and mortality. The researchers noted that this discovery could influence how both acute COVID-19 and long COVID are managed. Existing tests can detect several of the chronic viruses studied, and some herpes family viruses can be treated with antiviral medications.
"The next step is determining whether identifying and treating reactivated viruses can improve outcomes for patients with acute COVID-19 and long COVID," said Dr. Esther Melamed, the study's principal investigator. Long COVID, a chronic condition affecting millions globally, can manifest with a wide array of symptoms, including severe fatigue and cognitive impairment, with no currently approved treatments.
It is estimated that about one in six individuals infected with SARS-CoV-2 develop long COVID, often experiencing persistent health issues. Globally, over 400 million people are thought to have experienced long COVID, contributing to an estimated annual global economic impact of $1 trillion due to lost productivity and medical expenses.
While the study does not definitively prove that dormant virus reactivation causes long COVID, the findings provide evidence that it may play a role. This could aid scientists in better understanding and eventually treating the condition. As of early August, COVID-19 infections are reported to be increasing in a significant number of U.S. states, although the percentage of emergency room visits related to the virus remains low.