Hospital surveillance for respiratory syncytial virus (RSV) in the main metropolitan area of Lyon, France, using birth databases and data on hospitalization for clinical bronchiolitis from 2012 to 2017

Abstract

Background RSV is a leading cause of lower respiratory infections, particularly in infants and elderly. Morbidity and mortality are comparable to those of influenza infections in the high-risk population. Several RSV vaccine candidates and antibodies for prevention are currently in development, some of those already at phase III clinical trial stage. However, surveillance data on virus circulation and disease burden in high-risk groups are still incomplete, thus, hindering evidence-based recommendations on RSV vaccine policy and introduction. The main objective of this proof-of-concept (POC) study is to illustrate the feasibility of RSV surveillance in a main metropolitan area using birth databases and data on hospitalization for clinical bronchiolitis. Our concept would allow continuous monitoring and surveillance of RSV in infants and produce comparable data for main metropolitan areas in Europe in a practical and cost-efficient manner. Methods For this POC study, a case was defined as a hospitalized patient ( Results In total, 45,820 children were born in the study period of which 663 met the case definition. Incidence rates for birth cohorts of 2012 to 2016 were 16.3 (95% CI 13.7–18.9), 10.8 (95% CI 8.7–12.9), 15 (95% CI 12.5–17.5), 18.1 (95% CI 15.4–20.8) and 12.1 (95% CI 9.9–14.3) per 1000 newborns, respectively. No significant difference was found between hospitalization of male and female infants. The most predictive independent risk factor for RSV hospitalization was month of birth. Odd ratios gradually increased from 0.31 (95% CI 0.18–0.49) in May to 3.73 (95% CI 3.11–4.48) in November and were lowest in March with 0.26 (95% CI 0.14–0.43). Significant differences were found for duration of pregnancy and weight at birth between hospitalized and non-hospitalized children. Children born before week 38 or with a birth weight of 3000 g or less were more likely to be hospitalized due to RSV infection. Conclusion Seasonal RSV circulation is known to peak in December with younger infants being at higher risk of infection. Besides prematurity, month of birth is shown to be the greatest risk factor for hospitalization due to RSV infection. This results demonstrate that our concept of using already existing routine hospital databases, such as birth database and virological database, can produce reliable results to estimate the burden of RSV in the high risk group of under one year old children. This surveillance system could be implemented in other metropolitan areas to produce comparable dataset at no extra cost therefore, enabling data collection for evidence-based RSV vaccine recommendations.