Volume 30, Number 8—August 2024
Research
Wastewater Surveillance to Confirm Differences in Influenza A Infection between Michigan, USA, and Ontario, Canada, September 2022–March 2023
, Mackenzie Beach, Qiudi Geng, Ana Podadera, Owen Corchis-Scott, John Norton, Andrea Busch, Russell A. Faust, Stacey McFarlane, Scott Withington, Bridget Irwin, Mehdi Aloosh, Kenneth K.S. Ng, and R. Michael McKay
Table 1
Temporal shift at which peak synchrony was found between concentrations of influenza A in wastewater and influenza-associated hospitalizations for Windsor-Essex, Ontario, Canada (September 2022–March 2023), and Detroit, Michigan, USA (October 2022–March 2023)*
| Associations† | Peak synchrony, wk | Spearman ρ |
|---|---|---|
| WEC M1:PMMoV and influenza-associated hospitalizations | 1 | 0.797 |
| WEC M1 and influenza-associated hospitalization | 1 | 0.841 |
| DTW M1:PMMoV and influenza-associated hospitalizations | 0 | 0.708 |
| DTW M1 and influenza-associated hospitalizations | 0 | 0.769 |
| WEC M1:PMMoV and DTW M1:PMMoV | −3 | 0.642 |
| WEC M1 and DTW M1 | −3 | 0.695 |
*Peak synchrony was also found between Windsor-Essex and Detroit influenza A wastewater signals during September 2022–March 2023. Wastewater signals were shifted, and clinical metrics remained stationary. Positive values indicate a lagging wastewater signal and negative values indicate a leading wastewater signal. DTW, Detroit wastewater; M1, matrix 1 gene: PMMoV, pepper mottle mild virus; WEC, Windor-Essex County wastewater. †DTW M1, aggregate concentration of influenza A M1 gene (genome copies/mL) in DTW; DTW M1:PMMoV, concentration of influenza A M1 gene in DTW normalized to PMMoV (unitless); WEC M1, aggregate concentration of influenza A M1 gene in WEC (gc/L); WEC M1:PMMoV, concentration of influenza A M1 gene in WEC normalized to PMMoV concentration (unitless).