Enterovirus D68: A focused review and clinical highlights from the 2014 U.S. outbreak

Enterovirus D68 (EV-D68), a member of the Picornaviridae family, was first identified in 1962 and is part of a group of small, nonenveloped RNA viruses. As a family, these viruses are among the most common causes of disease among humans. However, outbreaks of disease attributable to EV-D68 have been rarely reported in the previous 4 decades. Reports from a few localized outbreaks since 2008 describe severe lower respiratory tract infection in children. In the late summer of 2014, EV-D68 caused a geographically widespread outbreak of respiratory disease of unprecedented magnitude in the United States. The Centers for Disease Control and Prevention was first notified of increased respiratory viral activity by Children's Mercy Hospitals (CMH) in Kansas City, Missouri, and EV-D68 was identified in 50% of nasopharyngeal specimens initially tested. Between mid-August and December 18, 2014, confirmed cases of lower respiratory tract infection caused by EV-D68 were reported in 1,152 people in 49 states and the District of Columbia. A focused review of EV-D68 respiratory disease and clinical highlights from the 2014 U.S. outbreak are presented here.