Table 3.
Detection rates and Ct values of spiked wastewater at marginal levels and unspiked wastewater samples.
| Spiked wastewater |
Unspiked wastewater |
|||||||
|---|---|---|---|---|---|---|---|---|
| Blank | Low | Medium | High | Total detection rates | Single detection rates | Lower Ct | Average Ct values | |
| Small-UC | 0 (0/2) | 0 (0/2) | 50% (1/2) | 100% (2/2) | 85.7% (30/35) | 5.7% (2/35) | 28.6% (8/28) | 33.88 ± 3.01 |
| Large-UC | 0 (0/2) | 0 (0/2) | 100% (2/2) | 100% (2/2) | 85.7% (30/35) | 5.7% (2/35) | 71.4% (20/28) | 32.85 ± 3.15 |
| TRIzol Kit | 0 (0/2) | 0 (0/2) | 50% (1/2) | 100% (2/2) | 67.7% (21/31) | 3.2% (1/31) | 20% (4/20) | 34.39 ± 2.68 |
| Viral Kit | 0 (0/2) | 50% (1/2) | 100% (2/2) | 100% (2/2) | 77.4% (24/31) | 12.9% (4/31) | 80% (16/20) | 33.46 ± 2.67 |
Blank: raw wastewater without spiking SARS-CoV-2 virus;
Low: SARS-CoV-2 virus-spiked wastewater with a concentration of approximately 1 copy/mL wastewater;
Medium: SARS-CoV-2 virus-spiked wastewater with a concentration of approximately 10 copies/mL wastewater;
High: SARS-CoV-2 virus-spiked wastewater with a concentration of approximately 100 copies/mL wastewater;
Total detection rates: the percentage of detectable samples for the chosen method;
Single detection rates: the percentage of samples which were only detectable for the chosen method;
Lower Ct: the percentage of samples with lower Ct values when detectable using both methods.