The Global Epidemiology of RSV in Community and Hospitalized Care: Findings From 15 Countries

Background: Respiratory syncytial virus (RSV) is one of the leading causes of acute respiratory tract infections. To optimize control strategies, a better understanding of the global epidemiology of RSV is critical. To this end, we initiated the Global Epidemiology of RSV study (GERi) to analyze virological surveillance data of RSV and understand current national surveillance practices. Methods: Focal points from 44 countries were approached to join GERi and share detailed RSV surveillance data. Countries completed a questionnaire on the characteristics of their surveillance system. A relative illness ratio was calculated when analyzing age related data. Results: Fifteen countries across four continents provided granular surveillance data and information on their surveillance system. A median of 1,641 (IQR:552 – 2,415) RSV cases per season were reported from 2000 and 2020. The majority (55%) of RSV cases occurred in the <1-year-olds, with 8% of cases reported in those aged ≥65 years. Hospitalized cases were younger than those reported in community care. We found no age difference between RSV subtypes and no clear pattern of dominant subtypes. The most notable difference between surveillance systems was the representativeness of the data. Interpretation: The high number of cases in the <1 year-olds, especially reported in hospitalized cases, indicates a need to focus prevention efforts in this age group. The minimal differences between RSV subtypes and their co-circulation implies prevention needs to target both subtypes. Importantly, our study found there appears to be lack of RSV surveillance data in the elderly. Funding Statement: Sanofi Pasteur / AstraZeneca. Declaration of Interests: CD and MB are Sanofi employees and may hold shares and/or stock options in the company; JP reports that Nivel has received RSV research grants from the Foundation for Influenza Epidemiology and Sanofi Pasteur. The remaining authors declare no competing interests. Ethics Approval Statement: The RSV surveillance is part of the Influenza surveillance protocol and was approved by the Spanish Inter-territorial Council of the National Health System. This is a rector group that ensures that public health measures are carried out in all the Spanish regions with a vision of equity. Since surveillance data is part of the public health response to the Influenza and other respiratory virus circulation, no explicit ethical evaluation was necessary. Although individual informed consent was not required, all data were pseudonymised to protect patient privacy and confidentiality