Clinical studies on the effectiveness of UVGI
As we have mentioned elsewhere, UVGI is a proven technology in the Americas, so there are a number of USA studies that have demonstrated its effectiveness. But we are pleased to note that studies are also being conducted in the UK:
- The importance of bioaerosols in hospital infections and the potential for control using germicidal ultraviolet irradiation. Read more ...
- Imperial College study shows UV air disinfection effective against TB
Upper room ultraviolet light and negative air ionization both prevent airborne tuberculosis transmission. Read more ... - High-dose ultraviolet C light inactivates spores of Bacillus subtilis var. niger and Bacillus anthracis Sterne on non-reflective surfaces. Read more ...
- Comparison of UV C light and chemicals for disinfection of surfaces in hospital isolation units. Read more ...
- Disinfection of Acinetobacter baumannii-contaminated surfaces relevant to medical treatment facilities with ultraviolet C light. Read more ...
The importance of bioaerosols in hospital infections and the potential for control using germicidal ultraviolet irradiation
L.A. Fletcher; C.J. Noakes; C.B. Beggs; P.A. Sleigh.
Aerobiology Research Group, School of Civil Engineering, University of Leeds
Research at the University of Leeds has looked at the effect of ultraviolet disinfection upon a range of airborne bacterial pathogens. The results have shown that all are susceptible to the effects of UV but the magnitude of the effect is extremely species-dependent. Although history shows that the uptake of UV disinfection has progressed slowly the future looks extremely promising, with increasing concerns over rising numbers of TB outbreaks, new pathogens such as SARS and avian flu and also the increased risk of bioterrorism threats. In addition to clinical applications, this technology would also be similarly applicable to waste management facilities for controlling potential pathogens such as Aspergillus fumigatus. You can read the full paper on the Leeds University site (PDF 
file).
Imperial College study shows UV air disinfection effective against TB
Rationale: Institutional TB transmission is an important problem necessitating studies of environmental control measures.
Objectives: To evaluate upper room ultraviolet germicidal irradiation (UV) and negative air ionization for preventing airborne TB transmission.
Dr Escombe
The Peru hospital
Setting: A guinea pig facility sampling the air from a TB ward in Lima, Peru.
Methods: Exhaust air from the TB ward was passed through three enclosures each housing 144 guinea pigs. On alternate days, ward air was passed over ‘control animals’ and ‘ionizer animals’ (ionizers located within that animal enclosure). On the other days, UV lights were turned on in the ward and ward air passed over ‘UV animals’. All guinea pigs had monthly tuberculin skin tests and positive reactors underwent autopsy and organ culture for TB.
Results: After 501 days there were 110 tuberculin-positives in the control animals, 53 in ionizer animals, and 30 in UV animals (p<0.001). Kaplan-Meier analysis of skin test data demonstrated that TB transmission was reduced by both ionizers (log rank 20.1; p<0.00001) and UV lights (log rank 46.6; p<0.00001). Autopsy and culture results lag behind skin tests and currently provide confirmatory evidence that UV is protective (log rank 3.6; p=0.05) in this ongoing experiment.
Conclusion: Despite Lima’s high humidity, upper room UV lights and negative air ionizers both prevented the majority of airborne TB transmission and these interventions should be considered in high-risk clinical settings.
Taken from The prevention of airborne TB transmission – Peru; reproduced with permission.Contact:
Dr Adrian R Escombe
Honorary Research Fellow
Division of Investigative Science
Imperial College London, South Kensington Campus, London SW7 2AZ
Email: rod.escombe@imperial.ac.uk
High-dose ultraviolet C light inactivates spores of Bacillus subtilis var. niger and Bacillus anthracis Sterne on non-reflective surfaces.
Marie U. Owens, David R. Deal, Michael O. Shoemaker, Gregory B. Knudson, Janet E. Meszaros, Jeffery L. Deal
(published in Applied Biosafety: Journal of the American Biological Safety Association). November 2005.
This investigation showed that spore viability of both B. subtilis var niger as well as B. anthracis Sterne was significantly reduced, reproducibly by 3-5 logs, under extreme contamination levels following dosimetric UV-C exposure. Complete kill can be achieved when the contamination level is lower.
Comparison of UV C light and chemicals for disinfection of surfaces in hospital isolation units
B. M. Andersen, MD, PhD; H. Bånrud, DrScient; E. Bøe, BcEcon, MEng; O. Bjordal, MEng; F. Drangsholt, PhD
Published in Infection Control and Hospital Epidemiology July 2006, vol. 27, no. 7
This study was to determine the bactericidal effect on surfaces of ceiling- and wall-mounted UV C (UVC) light in isolation units, compared with standard hospital environmental cleaning and chemical disinfection.
It found that UVC disinfection significantly reduced the number of bacteria on surfaces directly or indirectly exposed to UVC to a very low number. (Completely sh
adowed areas in the isolation unit (e.g., the bed rail, lockers, and mattresses) still required disinfection by chemicals.)Disinfection of Acinetobacter baumannii-contaminated surfaces relevant to medical treatment facilities with ultraviolet C light
Vipin K. Rastogi; Lalena Wallace; Lisa S. Smith.
Published in Military Medicine, Volume 172, Number 11, November 2007 , pp. 1166-1169
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