Matsie Mphaphlele1, Ashwin S Dharmadhikari2, Paul A Jensen3, Stephen N Rudnick4, Tobias H van Reenen5, Marcello A Pagano6, Wilhelm Leuschner7, Tim A Sears8, Sonya P Milonova4, Martie van der Walt9, Anton C Stoltz10, Karin Weyer11, Edward A Nardell2,12. 1. 1 MDR-TB Program, JHPIEGO, Pretoria, South Africa. 2. 2 Division of Pulmonary and Critical Care Medicine and. 3. 3 CDC Division of Tuberculosis Elimination, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Atlanta, Georgia. 4. 4 Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts. 5. 5 Council for Scientific and Industrial Research, Pretoria, South Africa. 6. 6 Harvard School of Public Health, Boston, Massachusetts. 7. 7 Department of Electronic and Computer Engineering, University of Pretoria, Pretoria, South Africa. 8. 8 Acuity Brands Lighting, Connors, Georgia. 9. 9 Medical Research Council, Pretoria, South Africa. 10. 10 Division of Infectious Diseases, Internal Medicine, University of Pretoria Medical School, Pretoria, South Africa; and. 11. 11 Global Tuberculosis Programme, World Health Organization, Geneva, Switzerland. 12. 12 Division of Global Health Equity, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts.
Abstract
RATIONALE: Transmission is driving the global tuberculosis epidemic, especially in congregate settings. Worldwide, natural ventilation is the most common means of air disinfection, but it is inherently unreliable and of limited use in cold climates. Upper room germicidal ultraviolet (UV) air disinfection with air mixing has been shown to be highly effective, but improved evidence-based dosing guidelines are needed. OBJECTIVES: To test the efficacy of upper room germicidal air disinfection with air mixing to reduce tuberculosis transmission under real hospital conditions, and to define the application parameters responsible as a basis for proposed new dosing guidelines. METHODS: Over an exposure period of 7 months, 90 guinea pigs breathed only untreated exhaust ward air, and another 90 guinea pigs breathed only air from the same six-bed tuberculosis ward on alternate days when upper room germicidal air disinfection was turned on throughout the ward. MEASUREMENTS AND MAIN RESULTS: The tuberculin skin test conversion rates (>6 mm) of the two chambers were compared. The hazard ratio for guinea pigs in the control chamber converting their skin test to positive was 4.9 (95% confidence interval, 2.8-8.6), with an efficacy of approximately 80%. CONCLUSIONS: Upper room germicidal UV air disinfection with air mixing was highly effective in reducing tuberculosis transmission under hospital conditions. These data support using either a total fixture output (rather than electrical or UV lamp wattage) of 15-20 mW/m(3) total room volume, or an average whole-room UV irradiance (fluence rate) of 5-7 μW/cm(2), calculated by a lighting computer-assisted design program modified for UV use.
RATIONALE: Transmission is driving the global tuberculosis epidemic, especially in congregate settings. Worldwide, natural ventilation is the most common means of air disinfection, but it is inherently unreliable and of limited use in cold climates. Upper room germicidal ultraviolet (UV) air disinfection with air mixing has been shown to be highly effective, but improved evidence-based dosing guidelines are needed. OBJECTIVES: To test the efficacy of upper room germicidal air disinfection with air mixing to reduce tuberculosis transmission under real hospital conditions, and to define the application parameters responsible as a basis for proposed new dosing guidelines. METHODS: Over an exposure period of 7 months, 90 guinea pigs breathed only untreated exhaust ward air, and another 90 guinea pigs breathed only air from the same six-bed tuberculosis ward on alternate days when upper room germicidal air disinfection was turned on throughout the ward. MEASUREMENTS AND MAIN RESULTS: The tuberculin skin test conversion rates (>6 mm) of the two chambers were compared. The hazard ratio for guinea pigs in the control chamber converting their skin test to positive was 4.9 (95% confidence interval, 2.8-8.6), with an efficacy of approximately 80%. CONCLUSIONS: Upper room germicidal UV air disinfection with air mixing was highly effective in reducing tuberculosis transmission under hospital conditions. These data support using either a total fixture output (rather than electrical or UV lamp wattage) of 15-20 mW/m(3) total room volume, or an average whole-room UV irradiance (fluence rate) of 5-7 μW/cm(2), calculated by a lighting computer-assisted design program modified for UV use.
Authors: Ashwin S Dharmadhikari; Randall J Basaraba; Martie L Van Der Walt; Karin Weyer; Matsie Mphahlele; Kobus Venter; Paul A Jensen; Melvin W First; Sydney Parsons; David N McMurray; Ian M Orme; Edward A Nardell Journal: Tuberculosis (Edinb) Date: 2011-04-07 Impact factor: 3.131
Authors: Ashwin S Dharmadhikari; Matsie Mphahlele; Anton Stoltz; Kobus Venter; Rirhandzu Mathebula; Thabiso Masotla; Willem Lubbe; Marcello Pagano; Melvin First; Paul A Jensen; Martie van der Walt; Edward A Nardell Journal: Am J Respir Crit Care Med Date: 2012-02-09 Impact factor: 21.405
Authors: A Roderick Escombe; David A J Moore; Robert H Gilman; Marcos Navincopa; Eduardo Ticona; Bailey Mitchell; Catherine Noakes; Carlos Martínez; Patricia Sheen; Rocio Ramirez; Willi Quino; Armando Gonzalez; Jon S Friedland; Carlton A Evans Journal: PLoS Med Date: 2009-03-17 Impact factor: 11.069
Authors: Shengwei Zhu; Jelena Srebric; Stephen N Rudnick; Richard L Vincent; Edward A Nardell Journal: Build Environ Date: 2014-02 Impact factor: 6.456
Authors: Ruvandhi R Nathavitharana; Payal K Patel; Dylan B Tierney; Preeti Mehrotra; Philip A Lederer; Sheila Davis; Edward Nardell Journal: J Hosp Med Date: 2020-04-23 Impact factor: 2.960
Authors: Andrew J Hoisington; Lisa A Brenner; Kerry A Kinney; Teodor T Postolache; Christopher A Lowry Journal: Microbiome Date: 2015-12-17 Impact factor: 14.650
Authors: David W Dowdy; Alison D Grant; Keertan Dheda; Edward Nardell; Katherine Fielding; David A J Moore Journal: J Infect Dis Date: 2017-11-03 Impact factor: 5.226