Prevalence and Risk Factors of Respiratory Syncytial Virus in Children Under 5 Years: A Systematic Review and Meta-Analysis

Background: Respiratory syncytial virus (RSV) is the major cause of respiratory tract infection in children under 5 years. However, RSV infection in the European region of the World Health Organization has not been systematically reviewed. Aim: To determine the prevalence and factors associated with RSV in children under 5 years of age in European regions. Methods: A systematic review and meta-analysis was performed. CINAHL, Medline, LILACS, ProQuest, SciELO and Scopus databases were consulted for studies publisehd in the last 5 years, following Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. The search equation was “respiratory syncytial virus AND (newborn OR infant OR child) AND (prevalence OR risk factors). Studies reporting the prevalence of RSV were eligible for inclusion in the meta-analysis. Findings: A total of 21 articles were included with a total sample of n = 24,465 children. The meta-analytic prevalence estimation of RSV, with a sample of n = 16,115 children, was 46% (95% CI 34–59%). The main risk factors were age, male gender, winter season and environmental factors such as cold temperatures, higher relative humidity, high concentrations of benzene and ozone, exposure to tobacco and living in urban areas. Interpretation: Robust age-specific estimates of RSV infection in healthy children should be promoted in order to determine the optimal age for immunization. In addition, it is necessary to analyze in greater depth the potentially predictive factors of RSV infection, to be included in prevention strategies. Funding Statement: None. Declaration of Interests: We declare no competing interests.