Table 2.
Spearman correlation coefficients between the daily new COVID-19 cases and SARS-CoV-2 concentration in wastewater: viral concentrations, viral loads per capita, and viral to faecal ratios. Different periods were selected: the entire period (15/09/2020–15/12/2021), 2nd wave (15/09/2020–01/11/2020), 3rd wave (15/02/2021–01/04/2021), and 4th wave (15/10/2021–01/12/2021). The number (N) of data included in the analysis is shown. All correlations were significant (p < 0.0001).
| Daily New Cases Correlation Against | Entire Period (N = 4984) |
2nd Wave (N = 507) |
3rd Wave (N = 558) |
4th Wave (N = 492) |
|---|---|---|---|---|
| Viral concentration (SARS-CoV-2 gene copies/mL) |
0.54 1 | 0.66 1 | 0.59 | 0.57 |
| Viral load per capita (SARS-CoV-2 gene copies/day/100 k inhab.) |
n.d. 2 | n.d. 2 | 0.52 | 0.52 |
| Viral to faecal ratio (SRAS-CoV-2 gene copies/PMMoV gene copies) |
n.d. 2 | n.d. 2 | 0.55 | 0.58 |
1 Estimated viral concentration data were used from 15/09/2020 to 15/02/2021 when quantified viral concentrations were not available. 2 n.d. denotes not determined. Viral loads per capita and viral to faecal ratios were computed when quantified viral concentrations were available.