Children can be asymptomatic carriers of COVID-19, but the extent of their contribution to droplet transmission is debated. To prevent COVID-19 transmission, both the Centers for Disease Control and Prevention and the American Academy of Pediatrics recommend that surgical masks be worn by children two years of age and older. A lingering concern has been that masks might cause oxygen desaturation or respiratory distress in infants and toddlers.

A research team in Italy undertook to test this concern, which, even after the current pandemic is over, will continue to be an important question in the management of future outbreaks. Their small study, published in JAMA Network Open, found that surgical masks do not appear to compromise respiratory function in healthy young children, at least when the masks are worn for a short period of time.

The researchers divided 47 healthy children into two groups: four to 24 months of age, and older than 24 months up to 12 years; the median age of participants was 12.5 months and 8.3 years, respectively. Parents were instructed on how to teach their children about proper mask wearing. The masks to be worn were disposable, three-layer masks with nasal clips and ear loops.

For the test, children were monitored for 30 minutes before donning a mask, and then while wearing a mask for 30 minutes of normal play activity. Children in the older group spent an additional 12 minutes walking rapidly with their masks in place. The respiratory parameters monitored during all three test periods were partial pressure of end-tidal carbon dioxide, oxygen saturation, perfusion index (a measure of peripheral blood perfusion and therefore an indicator of pulse oximeter accuracy), and pulse and respiratory rates. The children were observed for clinical signs of respiratory distress.

There were no significant differences in these parameters between the unmasked and masked time periods, other than the expected increase in pulse and respiratory rates while the older group was walking.

The researchers caution that the number of children tested was small and the test period short. In addition, the children were not tested during extremes of weather-for example, in hot or humid environments. But based on their results, the researchers recommend surgical mask wearing by young healthy children to prevent COVID-19 transmission, especially as schools reopen. They emphasize that constant adult supervision is still necessary when very young children wear masks.-Betsy Todd, MPH, RN