Prospective use of wastewater surveillance for early detection of enterovirus D68 in community outbreaks among children, Niigata City, Japan, 2024.

INTRODUCTIONEnterovirus D68 (EV-D68) is a re-emerging pathogen that can cause acute respiratory illness in children and difficult to predict outbreaks.AIMTo anticipate outbreaks in children, we investigated if wastewater surveillance could timely detect circulation of EV-D68 and its respective subclades in Niigata City, Japan.METHODSDuring January-December 2024, wastewater samples were collected once a week for EV-D68 RNA concentration determination. Numbers of children (≤ 15 years old) admitted with wheezing to six hospitals with paediatric beds in Niigata City were monitored; in a subset of children, nasopharyngeal swabs were tested for EV-D68 during September-December. Nucleotide sequences of EV-D68 derived from patient and wastewater samples were phylogenetically analysed.RESULTSDuring January-December 2024, EV-D68 RNA was found in 39 (41.9%) of 93 wastewater samples. The first EV-D68 detection occurred in week 27, with RNA concentrations rising in subsequent samples. From week 32, numbers of children hospitalised with wheezing increased, peaking in week 37. Up to week 52, 195 children with wheezing were admitted to the six hospitals. The wastewater EV-D68 RNA concentrations positively correlated with paediatric hospitalisations for wheezing (ρ = 0.54, p < 0.001). In weeks 37-52, 16 (10 girls/6 boys; median age: 4.8 years; interquartile range: 3.1-7.5) of 31 hospitalised children tested for EV-D68 were positive. Strains affecting them were of subclade B3 only, while strains in wastewater belonged to subclades D1 and B3.CONCLUSIONSWastewater surveillance timely detected an increase in EV-D68 activity, revealing the circulation of subclades undetected among patients. It thus can potentially support EV-D68 outbreak prediction and response and could possibly be extended to other pathogens.