Coronavirus infection and hospitalizations for acute respiratory illness in young children.

There is only limited knowledge on the burden of disease due to both new (HCoV-NL63 and HKU-1) and previously discovered coronaviruses (OC43 and 229E) in children. Respiratory specimens and clinical data were prospectively collected in an active, population-based surveillance study over a 2-year period from children aged <5 years hospitalized with acute respiratory symptoms or fever. These samples were retrospectively tested by real-time RT-PCR for HCoV-NL63, HKU1, OC43, and 229E. Human coronaviruses (HCoVs) were identified in 2.2% of study children <2 years of age. Rates of HCoV-associated hospitalization per 10,000 were 10.2 (95% CI 4.3, 17.6), 4.2 (95% CI 1.9, 6.9), and 0 (95% CI 0, 3.7) in children aged <6 months, 6-23 months, and 24-59 months, respectively. Coronaviruses were identified in a modest number of hospitalized children.