Researchers identify 55 lingering effects of COVID-19

Reviewed by Emily Henderson, B.Sc.Aug 30 2021

As COVID-19 hospitalizations once again soar in a fourth surge more than 18 months after the pandemic started, some patients continue to experience symptoms long after recovering from COVID, according to a Houston Methodist study recently published in Nature's Scientific Reports.

Lead author Sonia Villapol, Ph.D., an Assistant Professor of Neurosurgery at the Center for Neuroregeneration at Houston Methodist, and her collaborators detected more than 50 long-term effects of COVID-19 among the 47,910 patients included in the analysis. Topping the list, the most common of these lingering symptoms, which range from mild to debilitating and last weeks to months after initial recovery, are fatigue at 58%, followed by headache (44%), attention disorder (27%), hair loss (25%), shortness of breath (24%), loss of taste (23%) and loss of smell (21%).

Other symptoms were related to lung disease, such as cough, chest discomfort, reduced pulmonary diffusing capacity, sleep apnea and pulmonary fibrosis; cardiovascular issues, such as arrhythmias and myocarditis; and unspecific problems, such as tinnitus and night sweats. The researchers were surprised to also find a prevalence of neurological symptoms, such as dementia, depression, anxiety and obsessive-compulsive disorders.

To assess these long-term effects of COVID-19, the research team identified a total of 18,251 publications, of which 15 met the inclusion criteria for their study. The peer-reviewed studies they analyzed were conducted in the U.S., Europe, UK, Australia, China, Egypt and Mexico and consisted of data published before 2021, following patient cohorts ranging from 102 to 44,799 adults age 17-87 years.

The studies collected information from self-reported patient surveys, medical records and clinical evaluation, with post-COVID follow-up time ranging from 14 to 110 days. Patients hospitalized for COVID-19 made up 40% of the studies with the rest following a mix of mild, moderate and severe COVID-19 patients.

The research team performed a systematic review and meta-analysis of these studies to estimate the prevalence of all the symptoms, signs or abnormal laboratory parameters extending beyond the acute phase of COVID-19. They measured several biomarkers, including abnormal chest X-ray or CT scan, blood clot risk, presence of inflammation, anemia, and indicators of possible heart failure, bacterial infection and lung damage. They found 80% of recovered adults had at least one long-term symptom lasting weeks to months after acute infection with mild, moderate or severe COVID-19.

In total, the team identified 55 persistent symptoms, signs and abnormal laboratory results, with most of the lingering effects similar to the symptomatology developed during the acute phase of COVID-19. Identifying these same persistent effects across several countries, the researchers say their study confirms the burden of Long COVID is substantial and stress the urgency of recognizing these chronic complications, clearly communicating them to the community and defining therapeutic strategies to avoid long-term consequences from COVID-19. The next phase of their research will focus on determining what makes some individuals more susceptible to Long COVID.

Collaborating with Villapol on this study were Sandra Lopez-Leon with Novartis Pharmaceuticals, Talia Wegman-Ostrosky with Instituto Nacional de Cancerología in Mexico, Carol Perelman with National Autonomous University of Mexico, Rosalinda Sepulveda with Harvard T.H. Chan School of Public Health, Paulina A. Rebolledo with Emory University and Angelica Cuapio with Karolinska Institutet.