Flu/COVID Co-Infections Potentially More Severe in Kids, CDC Says

The CDC warned that co-infections with COVID-19 and influenza can potentially cause more severe illness in children, and need to be tracked.

Surveillance data from the 2021-2022 influenza season revealed that 6% of flu-related hospitalizations and 16% of flu-related deaths involved children co-infected with COVID-19, Katherine Adams, MPH, of the CDC in Atlanta, and colleagues reported.

Of the seven co-infected children who died, none had received the flu shot, although six were eligible, according to the findings in the Morbidity and Mortality Weekly Report.

Co-infected children were more likely to require bilevel positive airway pressure (BiPAP) or continuous positive airway pressure (CPAP) compared with those who only had the flu (16% vs 6%, respectively, P=0.05), and they were also more likely to need invasive mechanical ventilation (13% vs 4%, P=0.03).

Influenza antivirals were underutilized, “particularly among persons aged <18 years with influenza virus and SARS-CoV-2 co-infections who died,” the group wrote, noting that only one of the seven children who died had been given influenza antivirals.

The 2021-2022 influenza season had 44 pediatric deaths attributed to influenza, while to date there have already been 21 pediatric influenza deaths in the current 2022-2023 season.

“These findings represent a small number of cases of influenza and SARS-CoV-2 co-infection, thereby limiting the ability to draw firm conclusions,” the group cautioned, but added that “the high degree of co-circulation of multiple respiratory viruses during the current season, and the higher-than-usual early-season influenza activity, underscore the importance of increasing awareness among parents and providers that influenza and SARS-CoV-2 co-infections occur in pediatric patients and that co-infection can potentially cause more severe illness.”

For pediatric patients with acute respiratory illness symptoms with suspected severe illness, the researchers suggest performing tests for influenza, SARS-CoV-2, and other respiratory viruses to identify when there is more than one infection. This is “critical to facilitate early detection of co-infections and help guide clinical treatment and management,” wrote Adams and colleagues.

The data for their report were gathered from three CDC surveillance systems — including the Influenza Hospitalization Surveillance Network (FluSurv-NET) and the Influenza-Associated Pediatric Mortality Surveillance System — and identified 575 pediatric influenza-associated hospitalizations, including 32 patients who were coinfected with SARS-CoV-2.

The median age of the 32 children hospitalized with co-infection was 3 years (IQR 1-12 years). Four were vaccinated against the flu and 19 were not vaccinated, while five were ineligible.