TABLE 2.
Range of Log10 Reductions of MRSA, VRE, and Clostridium difficile Achieved with Inoculated Disk Carriers Exposed to UV-C for 5-Minute and 15-Minute Cycles on 3 Occasions at Each Cycle Time
| Distance and Orientation of Disks Relative to UV-C Device | Mean UV-C Dosage Measured Adjacent to Disks for 5-Min Cycles, µWsec/cm 2 | Range of Log10 Reduction with 5-Min Cycles, by Pathogen | Mean UV-C Dosage Measured Adjacent to Disks for 15-Min Cycles, µWsec/cm 2 | Range of Log10 Reduction with 15-Min Cycles, by Pathogen |
|---|---|---|---|---|
| 1.3 m (4 ft), direct | 342,667 | MRSA: >4 log | 842,000 | MRSA: >4 log |
| VRE: 4 to >4 log | VRE: >4 log | |||
| C. difficile: >2–3 log | C. difficile: 2 to >4 log | |||
| 1.3 m, 0° angle | 53,900 | MRSA: 4 to >4 log | 148,667 | MRSA: >4 log |
| VRE: 3 to >4 log | VRE: 3–4 log | |||
| C. difficile: 1–2 log | C. difficile: 2–4 log | |||
| 1.3 m, shaded | 8,547 | MRSA: 1–4 log | 24,467 | MRSA: >4 log |
| VRE: 2–3 log | VRE: 2–3 log | |||
| C. difficile: 0 | C. difficile: 1–2 log | |||
| 3.3 m (10 ft), direct | 67,567 | MRSA: 4 to >4 log | 202.667 | MRSA: >4 log |
| VRE: 3 to >4 log | VRE: >4 log | |||
| C. difficile: 1–3 log | C. difficile: 2–4 log | |||
| 3.3 m, 0° angle | 10,767 | MRSA: 4 to >4 log | 29,000 | MRSA: 4 to >4 log |
| VRE: 2 log | VRE: 3 log | |||
| C. difficile: 0–1 log | C. difficile: 0–2 log | |||
| 3.3 m, shaded | 3,395 | MRSA: 1–3 log | 8,880 | MRSA: 3 log |
| VRE: 1–2 log | VRE: 1–2 log | |||
| C. difficile: 0 | C. difficile: 0–1 log |
MRSA, methicillin-resistant Staphylococcus aureus; VRE, vancomycin-resistant Enterococcus; UV-C, ultraviolet C.