Wastewater-based surveillance of respiratory syncytial virus epidemic at the national level in Finland

Abstract

AbstractThe purpose of this study was to evaluate the potential of wastewater-based surveillance in the monitoring of epidemics at the national level in Finland. To discover the correlation of wastewater data and register data, the 2021–2022 respiratory syncytial virus (RSV) epidemic in Finland was analyzed from wastewater and the Finnish National Infectious Diseases Register. The study was performed using samples that were collected monthly from May 2021 to July 2022 from ten wastewater treatment plants that cover 40% of the Finnish population. Respiratory syncytial virus detection in 24-h composite samples of influent wastewater was performed using RT-qPCR. Respiratory syncytial virus wastewater data were positively correlated with the National Infectious Diseases Register data for the sampling week (correlation coefficient, CC min = 0.412, max = 0.865). Furthermore, the cumulative incidence of respiratory syncytial virus from the sampling week to three weeks afterward was strongly correlated with the wastewater data (CC min = 0.482, max = 0.814), showing the potential of wastewater-based surveillance for use in estimating the course of the epidemic. When the register-based incidence of RSV was at least four cases/100,000 persons/week in the sampling week, it was detected in all wastewater samples. This study showed that wastewater surveillance is useful in the surveillance of respiratory syncytial virus epidemics, and its potential in the surveillance of other epidemics should be explored further.SynopsisEnvironmental surveillance has been previously used to monitor viruses such as poliovirus and SARS-CoV-2. This study shows that wastewater-based surveillance can be used to surveil the respiratory syncytial virus and its epidemics, at a national level.