Bronchiolitis Due to RSV and HMPV-Epidemiology, Clinical Course, and Prognosis: Experience of a Single Tertiary Center.

Acute bronchiolitis is a leading cause of hospitalization in infants. In this retrospective study, 645 patients with acute bronchiolitis diagnosed as respiratory syncytial virus (RSV; n = 538) or human metapneumovirus (HMPV; n = 107) were compared in terms of demographic, clinical, and laboratory findings. The HMPV patients presented later in the winter, were older (20 vs 7.55 months; P < .001)), had higher levels of C-reactive protein (4.55 vs 3.03 mg/dL; P = .007), and a higher prevalence of complications (43.9% vs 32.7%; P = .03). This study highlights the similarities and differences between these 2 common respiratory viral pathogens and shows that HMPV has a slightly more severe disease course than RSV. These findings can help guide approaches to these 2 common viruses that cause bronchiolitis.