The Use of UV Light in Infection Control. John Burrows Managing Director Pathogen Solutions Ltd

Host (patient) Route of transmission THE SPREAD OF INFECTION The spread of infection within health care requires three elements: source ROUTES OF TRANSMISSION Contact Droplet and Airborne Infected food or drink Vectors

The ELECTROMAGNETIC SPECTRUM – UV-A:315 to 400 nanometres – UV-B:280 to 315 nanometres – UV-C:100 to 280 nanometres - germicidal UVc is the shortest wavelength and is a danger to the skin and eyes if over exposed The effective band width for germicidal function is nm

The ELECTROMAGNETIC SPECTRUM

– UV-A:315 to 400 nanometres – UV-B:280 to 315 nanometres – UV-C:100 to 280 nanometres - germicidal UVc is the shortest wavelength and is a danger to the skin and eyes if over exposed The effective band width for germicidal function is nm

Downes A., and Blunt T. P., “ Researches on the Effect of Light upon Bacteria and Other Organisms”, Proceedings of the Royal Society of Medicine, 26; 488, 1877 In 1877 Downes & Blunt investigated the effect of sunlight on bacteria. What Downes and Blunt had discovered was the germicidal effect of the ultraviolet light Discovery Terrence P. Blunt This led to the Neils Finsen’s, “Finsen Lamp” Sunlight Therapy anthrax, cholera, dysentery, the plague and tuberculosis

Ultraviolet Germicidal Irradiation UVGI

How is UV commonly applied In-duct irradiation of heating and ventilation systems Stand alone retro fit devices

FAN ®

UVc has poor propagation.. However there is a problem Within 5cm, of the light source 75% of the power has been dissipated! x 5

5cm 14,400  W cm -2 3,750  W cm -2 Power Dissipation

3,750  W / cm 2 x 4 = 15,000  W / cm 2 5cm The Solution

Power Distribution Cross Section through the machine Four lamps array Single Lamp

airspeed = 0.3m /sec L = 450mm t = 1.5s / cm 2 power = 15,000  W / cm 2 Therefore Minimum energy = 22,500  W sec / cm 2 Some simple maths: Exposure Time [energy = power x time] [energy = power x time]

Energy Requirements to Destroy Specific Micro-organisms Medixair produces 22,500µW s. cm -2 µW s. cm -2

Test 1 : Bacteria Testing “In the lab Medixair demonstrated between 6.0 to 7.0 log reductions against the challenge of three strains of bacterium” 1. 0 Organisms Employed ; Bacillus megaterium NCTC Bacillus globigii ATCC Bacillus subtilis ATCC Bacillus cereus NCTC 2599 Salmonella typhi murium NCTC 74 Ecoli 0157 H7 NCTC (ATTENUATED STRAIN: EX PUBLIC HEALTH SERVICE CULTURE) Staphylococcus aureusNCTC 8532 Aspergillus nigerNCPF 2275 Precipitation Only No UV

Energy Requirements to Destroy Specific Micro-organisms Medixair produces 22,500µW s. cm -2 µW s. cm -2

Test 4 Viral Particle Testing our data does demonstrate with a high degree of significance that the Medixair UVc air sterilisation unit was effective in reducing continuous doses of each virus over a 4.5-hour period. The corrected log inactivation data per 30 minute cycle in table 5 clearly illustrates a high and sustained level of inactivation for each viral target, with the range being measured at between 4.4 to 6.1 log reductions of challenge per 30 minutes with dosing at rates described above. Table (A) below details relating to the virus particles employed during this series of the experiments. Virus Nucleic acid Family E.coli T4 Phageds DNAMyoviridae (T4 like phages) FCoV A "+" ss RNANidovirales (genus corona virus) Saccaharomyces virus ScV-L-BC ds RNATotiviridae Vibrio phage fs1ss DNAInovirdiae Inactivation of T4 Phage -Continuous Challenge Virus Measured continuous mean log reduction of virus particles E.coli T4 Phage6.1 FCoV A 4.4 Saccaharomyces virus ScV-L-BC4.7 Vibrio phage fs15.3 Upstream Down stream

Ease of Use Quiet operation <33dB Zero Ozone Generation Safety for patients and healthcare workers Important Design Criteria Sustainable Solution

The Evidence

UV Room Control Room Cross Over UV Removed UV Installed No of positive swabs Data sets MRSA Side Wards - known hotspots North London NHS Hospital

Curtain 22% Bed 61% Floor 74% Light 30% Curtain 9% Bed 9% Floor 26% Light 9% UV-ROOMCONTROL- ROOM Patient 0% Patient 47% MRSA Side Wards - known hotspots North London NHS Hospital

UVc installation Clostridium difficile - surveillance data Orthopaedic Trauma Ward – North London NHS Hospital

Intervention in the chain of infection A proven science Easy to install QuietSafeSustainable Thank you for Listening.com