Epidemiology and seasonality of acute respiratory infections in hospitalized children over four consecutive years (2012–2016)

BACKGROUND: Acute respiratory infections are a principal cause of illness and mortality especially in young children worldwide. OBJECTIVES: To study the epidemiology and seasonality of viral respiratory infections in hospitalized children (under the age of 16) between September 2012 and August 2016. STUDY DESIGN: Nasopharyngeal swabs or aspirates were collected from 3199 symptomatic patients and then screened with a routine multiplex PCR assay. RESULTS: Respiratory viruses were detected for 1624 (50.8%) of the 3199 children in the study population. Of these, 210 (13.3%) were positive for two viruses, 28 (1.7%) were positive for three, and 3 (0.2%) were positive for four. The viral profile varied with age. Some viruses were significantly more frequent in children under the age of 1 month (such as human respiratory syncytial virus (p < 0.0001)), whereas others were significantly more frequent in children over that age (such as influenza viruses (p < 0.0001) and adenoviruses (p = .0006)). The distribution of viruses is variable over the year depending on the species. However, the atmospheric temperature was rarely found to be a limiting factor in the circulation of respiratory viruses. CONCLUSIONS: our results constitute a detailed description of the distribution of respiratory viruses among hospitalized children over four consecutive years. Our data notably highlight the persistence of non-enveloped viruses and some enveloped viruses throughout the year–regardless of temperature variations.