Comparison of infections with respiratory syncytial virus between children and adults: a multicenter surveillance from 2015 to 2019 in Beijing, China

The objective of this study is to investigate the epidemiological and clinical characteristics of the acute respiratory tract infections (ARTI) caused by respiratory syncytial virus (RSV) among the population of all age categories in Beijing, China. Outpatients and inpatients with ARTI were enrolled from 35 sentinel hospitals in Beijing between March 2015 and February 2019. They were interviewed and their medical records were collected using a standardized form. Their respiratory specimens were collected and tested for the nucleic acid of RSV. The RSV-positive specimens were further genotyped into RSV-A and RSV-B groups. A total of 29,923 cases were included in this study. RSV was detected in 623 (2%, 623/29923) patients, with 391 (62.8%) genotypd as RSV-A, 126 (20.2%) as RSV-B, and 106 (17.0%) untyped. The RSV epidemic season usually occurred between October and March covering approximately 90% of annual RSV infections. The RSV-infected children aged < 5 years accounted for 52.2% of the total RSV infections with cough and fever as the most common manifestations. The RSV-infected elderly adults aged ≥ 60 years have the second largest proportion (25.2%) with dyspnea and lymphocytopenia as the most common manifestations and showed an elevated rate of hospitalization, an increased rate of ICU admission, an extended length of hospital stay, and an elevated mortality compared to the RSV-infected children. The RSV infections aged ≥ 60 years old, as the second largest population of the total annual RSV infections, usually developed worse outcomes than children and should be taken seriously.