Table 3.
Predicted probabilities of SARS-CoV-2 RNA detection at the WWTP by selected equivalent case counts (per 100,000 population) from logistic regression models fitted with community cluster data.
| COVID-19 case count per 100,000 (prevalence) | Expected probability of positive tests in WWTP wastewater (95% Confidence interval) |
|||
| Total cases (model 1) | Infectious cases (model 2) | Relative infectious cases (model 3) | New daily cases (model 4) | |
| 1 (0.001%) | 24% (13 – 38) | 19% (10 – 34) | 29% (18 – 43) | 46% (36 – 56) |
| 5 (0.005%) | 28% (17 – 42) | 28% (17 – 41) | 58% (47 – 68) | 74% (57 – 86) |
| 10 (0.01%) | 34% (23 – 46) | 41% (30 – 52) | 87% (70 – 95) | 93% (70 – 99) |
| 20 (0.02%) | 47% (37 – 58) | 69% (56 – 80) | 99% (92 – 100) * | – |
| 40 (0.04%) | 74% (59 – 85) | 96% (83 – 99) | 100% (99 – 100) * | – |
* Extrapolation beyond available data.