SARS-CoV-2 RNA in the Blood is Associated With Worse Outcomes in Kids

SARS-CoV-2 RNA in the Blood is Associated With Worse Outcomes in Kids 1024 575 Katie Brind'Amour, PhD, MS, CHES

Researchers have identified a risk factor for more severe illness in children with COVID-19: detectable levels of SARS-CoV-2 RNA circulating in the blood.

Children with detectable SARS-CoV-2 RNA in the blood, called RNAemia, were more likely to require oxygen and be admitted to the intensive care unit than children with COVID-19 who did not have detectable RNAemia. This finding, based on a study of 103 children who tested positive for COVID-19, may help identify a subset of children at risk for severe disease.

“Detection of viral RNA in the blood is not common with other respiratory viruses, and when you find it -especially in patients with abnormal immune systems – it is associated with severe outcomes,” says M. Asuncion Mejias, MD, PhD, principal investigator in the Center for Vaccines and Immunity at the Abigail Wexner Research Institute and an infectious disease clinician at Nationwide Children’s Hospital.

“Extrapolating what we knew from other viruses and emerging findings in adults, we decided to assess how common SARS-CoV-2 RNAemia was in children hospitalized with COVID_19 and whether it was associated with worse clinical outcomes,” says Octavio Ramilo, MD, chief of the Division of Infectious Diseases at Nationwide Children’s, who co-led the study with Dr. Mejias.

Dr. Mejias, Ramilo and colleagues conducted the study using blood samples from a convenience sample of patients ages 20 and younger admitted to Nationwide Children’s who tested positive for SARS-CoV-2 from March 2020 to May 2021.

SARS-CoV-2 RNAemia was detected in 26 patients who had symptomatic COVID-19, representing 33% of the symptomatic COVID-19 cohort (n=80); it was also detected in one child that presented with a ruptured appendix (representing 4% of the 23 patients identified by screening only). Patients with RNAemia had a shorter duration of symptoms at the time of study enrollment and were more likely to have higher viral loads in respiratory samples, fever and lymphopenia. They were also more likely to receive anti-COVID-19 therapies, oxygen and admission to the ICU.

Patients with RNAemia had slightly longer hospital stays and were younger (median age of 1.6 years vs 11.1 years) than non-RNAemia patients, but these differences did not reach statistical significance. Underlying diseases, race, ethnicity and sex were not associated with RNAemia or clinical outcomes.

“COVID can be so unpredictable in hospitalized children in the hospital,” Dr. Mejias says. “This could be a tool to help us assess and classify our patients and the severity of their disease, with the opportunity to maybe implement earlier interventions.”

The study is the largest examining the relationship between blood RNAemia and COVID-19 severity in pediatric patients as of press time. Further work is in progress with a much larger sample size to confirm the link and explore the potential mechanisms behind RNAemia and host response to SARS-CoV-2 infection.

This article appears in the 2022 Spring/Summer print issue. Download the full issue.


Mertz C, Glowinski R, Cohen SH, Mertz S, Ye F, Hall MW, Peeples ME, King T, Wang H, Leber AL, Sanchez PJ, Ramilo O, Mejias A. SARS-CoV-2 RNAemia and clinical outcomes in children with COVID-19. The Journal of infectious Diseases. 2022;225(2):208-213.

About the author

Katherine (Katie) Brind’Amour is a freelance medical and health science writer based in Pennsylvania. She has written about nearly every therapeutic area for patients, doctors and the general public. Dr. Brind’Amour specializes in health literacy and patient education. She completed her BS and MS degrees in Biology at Arizona State University and her PhD in Health Services Management and Policy at The Ohio State University. She is a Certified Health Education Specialist and is interested in health promotion via health programs and the communication of medical information.