Epidemiological and Clinical Characteristics of Hospitalized Human Metapneumovirus Patients in Israel, 2015-2021: A Retrospective Cohort Study

This study evaluated the epidemiological and clinical characteristics of human metapneumovirus (hMPV) infection among hospitalized patients with acute respiratory infections during 2015-2021 and assessed the impact of the coronavirus disease 2019 pandemic on hMPV infection. A single-center, retrospective cohort study was performed, including pediatric and adult patients with laboratory-confirmed hMPV. Of a total of 990 patients, 253 (25.6%), 105 (10.6%), 121 (12.2%), and 511 (51.6%) belonged to age groups 0-2, 3-17, 18-59, and >= 60 years, respectively. The highest percentage (23.0%) of patients were hospitalized during 2019 and the lowest (4.7%) during 2020. Patients < 18 years experienced high rates of comorbidities (immunodeficiencies: 14.4% and malignancies: 29.9%). Here, 37/39 (94.9%) of all bronchiolitis cases were diagnosed in patients < 2 years, whereas more patients in older age groups were diagnosed with pneumonia. A greater proportion of hMPV patients diagnosed with viral coinfection (mostly respiratory syncytial virus and adenovirus) were <18 years. The highest percentages of intensive care unit admissions were recorded among patients < 18 years. Our findings demonstrate that hMPV is an important cause of morbidity in young children and a possibly underestimated cause of morbidity among older adults.