The burden of respiratory syncytial virus infection in children in Shanghai, China,2014 to 2022：a retrospective observational study
Authors: Yu Qiumiao , Zhang Li , Zhang Xuechun , Wu Rongxin , Xu Hongmei , Yuan Yang , Zhang Lu , Zhao Bing , Ye Chuchu , Wang Yuanping 
Published: April 2024

Background
Respiratory syncytial virus (RSV) is one of the primary pathogens responsible for acute lower respiratory tract infections in children. Most studies assessing the detection rate in children have utilized the method of sentinel hospital surveillance. While this method can partially reflect the disease burden on the population, it does not fully account for the catchment area of sentinel hospitals in the study population. Hence, the relevant weight was adjusted through etiological monitoring and community consultation behavior parameters. The incidence of RSV in children in the Pudong New Area of Shanghai can be estimated more accurately.
Objectives
The study aimed to protect the incidence rates of respiratory syncytial virus(RSV) in outpatient, emergency departments, and community children in Pudong New Area, Shanghai. Also included are the data on the burden of lower respiratory infections due to respiratory syncytial virus in children. This data will serve as a foundation for formulating healthcare policies and conducting health economic evaluations.
Methods
Between 2014 and 2022, acute respiratory infection (ARI) patients were monitored every 1 week at sentinel hospitals, we obtained basic characteristics of ARI patients and detected the viruses. We analyzed the infection characteristics of RSV in various years and among different populations. In 2022, we established investigation sites throughout the district and conducted the Hospitalized Utilization and Attitude Survey (HUAS) on 3,225 community residents aged 14 and below. This survey aimed to understand the healthcare-seeking behaviors of children after experiencing ARI and to determine the coverage rate of sentinel hospitals and the ARI visit rate among the population. By combining the results from the ARI sentinel surveillance, we estimated the outpatient and community incidence rates of pediatric RSV. The comparison of rates was using chi-square tests, with a significance level of P < 0.05 indicating statistically significant differences.
Results
From 2014 to 2022, RSV positive was at a rate of 5.36%. Among males, there were 126 cases (5.78%), which was higher than the 90 cases (4.86%) among females. As for the distribution by age group, the highest rates were seen in the under-three age group. There were significant differences in the positive detection rates among different age groups, with statistical significance (P < 0.001). The hospitalization detection rate (10.54%) was higher than the outpatient rate (2.67%), and the difference between the two was statistically significant. According to the HUAS results, the estimated ARI incidence rate was approximately 33.74%. The ARI visit rate was approximately 36.67%. The estimated number of RSV outpatient patients from 2014 to 2022 was 428,500 for a rate of 6.58 per 100. The number of community cases was estimated to be around 1,168,500 for a rate of 17.95 per 100, There were variations in outpatient and community incidence rates across different years. In 2015, both the outpatient and community incidence rates reached their peak values, at 15.39% and 41.96%, respectively. Additionally, except for the peak in 2019 occurring in the spring, the incidence rates for the other eight years peaked in the autumn season.
Conclusions
This study is the first to combine sentinel hospital surveillance with a community health service utilization survey to provide an initial assessment of the burden of RSV in the Pudong New Area. The burden of RSV in children in Pudong New Area was found to be more severe in 2015 and 2017, followed by a declining trend. Furthermore, the autumn season was identified as the peak period for RSV incidence in children in Pudong New Area.