Cases of respiratory syncytial virus in the U.S. have been on the rise since February, with nearly 500 cases reported in the week ending May 22, CDC data shows.
While RSV typically peaks in the fall, cases remained low throughout the fall of 2020 and early winter, likely due to widespread COVID-19 pandemic safety measures such as social distancing and mask wearing. In March, however, RSV cases detected by polymerase chain reaction tests jumped from 73 to 143 during the week ending March 13, the CDC reports.
New York City-based Maimonides Children's Hospital didn't see its first RSV patient for the 2020-21 fall season until February. Across the following few months, 197 children were admitted to the hospital with RSV, and 81 percent were admitted to the pediatric intensive care unit. A total of six patients were placed on ventilators, according to a pre-print study published June 9 in Pediatrics.. Just 45 percent of pediatric RSV patients were admitted to the ICU during the previous year's season, according to the findings.
"Our data indicates more severe disease in younger infants possibly due to diminished immunity from lack of exposure to RSV in the previous season," the researchers said. "Although our early findings cannot predict the height of the RSV surge or how long it may last, it does suggest that institutions should plan ahead for an increase in pediatric emergency visits and potentially a need for increased pediatric [intensive care unit] capacity in the coming weeks."