Table 1.
Differences in the infectious titer after continuous and pulsed DUV-LED irradiation for the UK, South African, and Brazilian strains irradiated with different patterns of DUV-LED light for 0, 1, 5, or 10 s.
| Control (No Irradiation) |
DUV-LED Irradiation Time (n = 3, Each) | |||||||
|---|---|---|---|---|---|---|---|---|
| 1 s | 5 s | 10 s | ||||||
| Continuous Irradiation |
Pulsed Irradiation |
Continuous Irradiation |
Pulsed Irradiation |
Continuous Irradiation |
Pulsed Irradiation |
|||
| UK strain | PFU (PFU/mL) | 3.5 × 104 | 1.3 × 103 | 1.9 × 103 | <20 | 4.0 × 101 | <20 | <20 |
| Log PFU ratio a | - | 1.5 ± 0.4 | 1.3 ± 0.1 | >3.2 | 3.0 ± 0.3 | >3.2 | >3.2 | |
| Infectious titer reduction rate b (%) | - | 96.3 | 94.4 | >99.9 | 99.9 | >99.9 | >99.9 | |
| South African strain | PFU (PFU/mL) | 5.3 × 104 | 2.9 × 103 | 3.5 × 103 | <20 | 5.3 × 101 | <20 | <20 |
| Log PFU ratio a | - | 1.3 ± 0.1 | 1.2 ± 0.1 | >3.4 | 3.1 ± 0.4 | >3.4 | >3.4 | |
| Infectious titer reduction rate b (%) | - | 94.6 | 93.4 | >99.9 | 99.9 | >99.9 | >99.9 | |
| Brazilian strain | PFU (PFU/mL) | 1.1 × 104 | 8.7 × 102 | 1.7 × 103 | <20 | <20 | <20 | <20 |
| Log PFU ratio a | - | 1.1 ± 0.3 | 0.8 ± 0.0 | >2.7 | >2.7 | >2.7 | >2.7 | |
| Infectious titer reduction rate b (%) | - | 91.9 | 84.4 | >99.8 | >99.8 | >99.8 | >99.8 | |
a log10 (Nt/N0) where Nt is the PFU count of the UV-irradiated sample and N0 is the PFU count of the sample without UV irradiation. Data are shown as mean ± SD. b (1 − 1/10log PFU ratio) × 100 (%).