Kids’ Colds Didn’t Take a Break During the Pandemic

As cases of influenza and other respiratory viruses plummeted during the COVID-19 pandemic for kids and adults alike, rhinovirus and enterovirus continued to infect children at typical rates, a multicenter study suggested.

In a surveillance analysis involving more than 35,000 children who presented to emergency departments or were hospitalized for acute respiratory illness, 29.6% tested positive for enterovirus or rhinovirus in the March 2020 to January 2021 season, similar to rates for two prior seasons (30.4% for 2019-2020 and 29.0% for 2017-2018), reported Danielle Rankin, MPH, CIC, of Vanderbilt University in Nashville.

And the combined positivity rate of influenza, respiratory syncytial virus (RSV), and other respiratory viruses (39.5%) was significantly lower in 2020-2021 compared to each of the prior three seasons (P<0.001):

• 2019-2020: 75.4%
• 2018-2019: 71.3%
• 2017-2018: 69.4%

Findings from the study were presented at virtual IDWeek, the annual joint meeting of the Infectious Diseases Society of America, Society for Healthcare Epidemiology of America, Pediatric Infectious Diseases Society, HIV Medicine Association, and Society of Infectious Diseases Pharmacists.

“It has been previously shown that mitigation measures, like mask wearing or social distancing, which were introduced to limit the spread of SARS-CoV-2, also limited the spread of influenza, RSV, and some other respiratory viruses,” Rankin said in a press release. “This study showed rhinovirus/enterovirus slightly decreased in March 2020, but shortly after resumed and persisted.”

Severe disease with rhinovirus/enterovirus can occur in infants, the immunocompromised, and the elderly, Rankin noted. In an average year, she explained, adults will experience one rhinovirus/enterovirus infection while children will experience two.

“The fact that we continued to see rhinovirus says there is something virologically different about it,” said co-investigator Natasha Halasa, MD, MPH, also of Vanderbilt, in a press release.

For their study, the researchers analyzed data on 37,676 children (of 69,403 eligible) who presented to emergency departments or were hospitalized for acute respiratory illness and tested positive for a respiratory virus from December 2016 to January 2021 at seven pediatric hospitals participating in the CDC’s New Vaccine Surveillance Network.

The study’s primary outcome was cumulative percent positivity for each respiratory virus — rhinovirus/enterovirus, influenza, parainfluenza (type 1-4), RSV, adenovirus, human metapneumovirus — as detected by nose and throat specimens.

Rankin noted several limitations of the study: seven sites may not fully represent the U.S., assays cannot distinguish between rhinovirus and enterovirus, seasonal coronaviruses were not evaluated, and outpatient clinics were not included.