RSV Surge: Winter Virus Defies Spring Season

A dangerous winter virus, Respiratory Syncytial Virus (RSV), is continuing its nationwide spread well beyond its typical March peak. Current federal data indicates that 7.5 percent of RSV tests are returning positive, a notable increase compared to the five percent rate observed at this time last year. In response to this prolonged season, numerous states have made the unprecedented decision to extend their RSV immunization periods through at least April 30. This unusual timing has led the Centers for Disease Control and Prevention (CDC) to warn that higher RSV activity may persist into April across many regions.

Wastewater surveillance data from the CDC reveals that the Midwest and northern Plains are currently experiencing the most significant circulation of the virus. States like Michigan, Minnesota, South Dakota, Wyoming, Iowa, Kansas, Nebraska, and Vermont reported high or very high levels of RSV in wastewater samples in late March. While emergency room visits and hospitalizations are beginning to decrease, they remain highest among children under four years old, particularly infants under eight months who are vulnerable to severe complications such as bronchiolitis and pneumonia. Vaccination remains recommended for infants and high-risk older adults.