Enterovirus D68 in Critically Ill Children: A Comparison With Pandemic H1N1 Influenza*

Objective: In 2014, the Unites States experienced an outbreak of enterovirus D68 associated with severe respiratory illness. The clinical characteristics associated with severe illness from enterovirus D68 during this outbreak compared with those associated with the 2009 H1N1 influenza virus outbreak are unknown. Design and Setting: In this retrospective cohort study, we characterized the clinical features of children with enterovirus D68 admitted to the PICU between August 1, 2014, and November 1, 2014, and compared them with critically ill children infected with H1N1 influenza during the pandemic admitted between May 1, 2009, and January 31, 2010. Patients: PICU patients. Interventions: None. Measurements and Main Results: Ninety-seven severely ill children with enterovirus D68 infections were compared with 68 children infected with H1N1 influenza during the 2009 pandemic. Children with enterovirus D68 were more likely to have asthma (62% vs 23%; p < 0.001) and present with reactive airway disease exacerbations, with greater receipt of albuterol (94% vs 49%) and steroids (89% vs 40%; p < 0.0001 for both). Although more children with enterovirus D68 were admitted to the ICU compared with those with H1N1 influenza, they had a shorter hospital length of stay (4 vs 7 d; p < 0.0001), with lower intubation rates (7% vs 44%), vasopressor use (3% vs 32%), acute respiratory distress syndrome (3% vs 24%), shock (0% vs 16%), and death (0% vs 12%; p < 0.05 for all). Compared with children with other enteroviruses and rhinoviruses, children with enterovirus D68 were more likely to have a history of asthma (64% vs 45%) or multiple prior wheezing episodes (54% vs 34%; p < 0.01 for both). Conclusions: Critically ill children with enterovirus D68 were more likely to present with reactive airway disease exacerbations, whereas children with H1N1 influenza were more likely to present with pneumonia. Compared with the pandemic H1N1 influenza outbreak, the enterovirus D68 outbreak resulted in more children requiring admission to the ICU, but was associated with less severe outcomes.