Background: The incidence of enterovirus D68 (EV-D68) and the spectrum of clinical disease in children are not well known in European countries. We have designed a study with the objective of describing the clinical impact of EV-D68 detected in children with respiratory tract infections.

Methods: As a part of a prospective study to identify the etiology and clinical characteristics of viral respiratory infections in children in Spain, we performed the analysis of the cases of EV infections in all children hospitalized in a secondary hospital in Madrid, during the epidemic respiratory season 2012-2013. A second group of samples was corresponded to infants of the same area, with ambulatory respiratory infection or asymptomatic. Phylogenetic EV-D68 analysis was made using the viral protein 1 gene (VP1). Clinical data of EV-D68 patients were compared with those infected by rhinovirus in the same period and population.

Results: The study population consisted of 720 patients corresponding to 399 episodes of hospitalization for respiratory causes, 44 episodes of ambulatory respiratory infections and 277 children determined as a healthy control group. A total of 22 patients were positive for EVs (3.05%), and 12 of them were specifically typed as EV-D68 (11/443 respiratory infections, 2.5%). The most frequent diagnosis in the 10 hospitalized children with EV-D68 detection was recurrent wheezing. Hypoxia was present in 70% of cases, but admission in the intensive care unit was not required. No neurological signs or symptoms were observed. One patient had an ambulatory mild bronchiolitis and another was asymptomatic. No differences were found with rhinovirus infections except less duration of hypoxia and fever in EV-D68 group.

Conclusions: EV-D68 infections were detected in 3.05% of respiratory studied samples (2.5% of admissions). The infection was associated with wheezing episodes with hypoxia. No admissions to intensive care unit or neurological symptoms were found.