Clinicians should be on the alert for severe respiratory illness in children that might be caused by infection with a rarely seen virus, enterovirus D-68 (EV-D68), according to federal health officials. This advice, from the US Centers for Disease Control and Prevention (CDC), was prompted by clusters of severe respiratory illness in children in Missouri and Illinois that emerged in August. The CDC wants “to make sure that clinicians around the country are on the lookout for this, and health departments are ready to support clinicians,” said Anne Schuchat, MD, director of CDC’s National Center for Immunization and Respiratory Diseases, during a September 8 telebriefing. Children with asthma appear to be especially vulnerable, the agency said.