Wastewater surveillance confirms population wide differences in Influenza A infection trajectory across a major North American land border

Wastewater surveillance (WS) is an effective means to track community infections and potentially the spread of pathogens across jurisdictional boundaries. A retrospective WS study of the 2022-23 Influenza A (IAV) season was carried out for two communities (Detroit, MI and Windsor-Essex, ON) forming North America largest cross-border conurbation. Analysis of WS data, coupled with traditional measures of disease incidence, will allow a better understanding of how a regulated border and differences in public health approaches in a divided, yet contiguous metropolitan area influenced the trajectory of the IAV season following the removal of infection spread mitigation policies for COVID-19.