Tracking Norovirus in Tri-County Detroit, MI, Using\nWastewater Testing, Syndromic Data, and Online Publicly Available\nSources

Human norovirus (HuNoV),\nthe leading cause of acute gastroenteritis\nin the U.S., is voluntarily reported to the U.S. Center for Disease\nControl and Prevention (CDC) when infected individuals do not require\nhospitalization. Wastewater surveillance can be valuable in monitoring\nHuNoV trends and complementing under-reported clinical data. In this\nstudy, wastewater samples were collected between January and December\n2023 from three interceptors in Tri-County Detroit, Michigan. HuNoV\ngenogroup I (GI) and genogroup II (GII) were quantified, and the highest\nconcentrations were observed during the winter season. HuNoV GI and\nGII and their sum were normalized by water quality parameters and\nfecal indicators. Pearson correlation and dynamic time warping (DTW)\nanalysis were implemented to compare wastewater viral concentrations,\nin normalized and non-normalized scenarios, with clinical and online\ndata sets. Using the DTW method, HuNoV concentrations in wastewater\nnormalized by fecal indicators and norovirus-positive PCR detection\nrates in the Midwest U.S. (NPM), followed by Google Trends for “norovirus”,\ndemonstrated the most similar patterns. This study highlights the\nimportance of using multiple data sets, including wastewater surveillance,\nto identify disease trends, especially for under-reported diseases.