(HealthDay News) — A high burden of persistent symptoms is observed in persons after COVID-19, but no specific causes of symptoms of postacute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection (PASC) have been identified, according to a study published online May 24 in the Annals of Internal Medicine.
Michael C. Sneller, M.D., from the National Institutes of Health in Bethesda, Maryland, and colleagues enrolled self-referred adults with laboratory documented SARS-CoV-2 infection who were at least six weeks from symptom onset, regardless of the presence of PASC, to characterize medical sequelae and persistent symptoms after recovery from COVID-19. They were compared to controls with no history of COVID-19 or serologic evidence of SARS-CoV-2 infection. A total of 189 persons with COVID-19 and 120 antibody-negative controls were included.
At enrollment, 55 and 13 percent of the COVID-19 cohort and controls had symptoms consistent with PASC, respectively. The researchers found that the risk for PASC was increased in women and those with a history of anxiety disorder. Lower quality of life was reported by participants with findings meeting the definition of PASC. Abnormal findings on physical examination and diagnostic testing were seen infrequently. In 27 percent of the unvaccinated COVID-19 cohort and none of the vaccinated COVID-19 cohort, neutralizing antibody levels to spike protein were negative. In participants with PASC, there was no evidence of persistent viral infection, autoimmunity, or abnormal immune activation in exploratory studies.
“The pathogenesis of PASC remains unclear and requires further study,” the authors write.