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Efficacy of Portable Filtration Units in Reducing Aerosolized Particles in the Size Range of Mycobacterium Tuberculosis

Published online by Cambridge University Press:  02 January 2015

William A. Rutala*
Affiliation:
Department of Hospital Epidemiology, UNC Hospitals, University of North Carolina at Chapel Hill Division of Infectious Diseases, University of North Carolina at Chapel Hill
Suzanne M. Jones
Affiliation:
Department of Hospital Epidemiology, UNC Hospitals, University of North Carolina at Chapel Hill
John M. Worthmgton
Affiliation:
Health and Safety Office, University of North Carolina at Chapel Hill
Parker C. Reist
Affiliation:
Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill
David J. Weber
Affiliation:
Department of Hospital Epidemiology, UNC Hospitals, University of North Carolina at Chapel Hill Division of Infectious Diseases, University of North Carolina at Chapel Hill
*
Division of Infectious Diseases, 547 Burnett-Womack Bldg., CB #7030, University of North Carolina at Chapel Hill, Chapel Hill, NC, 275997030

Abstract

Objective:

To evaluate engineering control measures to prevent nosocomial transmission of diseases such as tuberculosis, we studied four portable high-efficiency air filtration units, including three high-efficiency particulate air (HEPA) filtration units, for their ability to remove aerosolized particles.

Design:

Studies were conducted in either a non-ventilated aerosol chamber or in a hospital isolation room that met CDC guidelines for TB control (negative pressure, ≧6 air changes per hour, air exhausted directly to the outside). The rooms were challenged with aerosolized mineral oil in the size range of 0.3 to 5.0 μm at levels 10 to 20 times the normal airborne particle load in the room at baseline. Airborne particles were counted with a laser counter capable of simultaneously measuring sizes ≧ = 0.3, ≧ 0.5, ≧ 1.0, and ≧ 5.0 μm. Experimental runs were conducted with the filtration units in the center or comer of the chamber or room, and the particle counter in the center of the room or at the exhaust vent.

Results:

Portable filtration units were effective in accelerating the removal of aerosolized submicron particles. In the nonventilated room, time required by the various portable filtration units for removal of 90% of aerosolized particles (≧ 0.3 μm) ranged from a low of 5 to 6 minutes to a high of 18 to 31 minutes, compared to the control (no filtration unit), >171 minutes. In the hospital room, individual filtration units removed 90% of aerosolized particles ( ≧ 0.3 μm) in times ranging from 5 to 8 minutes to 9 to 12 minutes, compared to the control (no filtration unit), 12 to 16 minutes. The location of the portable filtration unit (center versus comer) did not affect the clearance rate of airborne particles.

Conclusion:

Our data indicate that portable filtration units can rapidly reduce levels of airborne particles similar in size to infectious droplet nuclei and, therefore, may aid in reducing the risk of tuberculosis exposure.

Type
Original Articles
Copyright
Copyright © The Society for Healthcare Epidemiology of America 1995

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References

REFERENCES

1.Centers for Disease Control and Prevention. Emerging infectious diseases: tuberculosis morbidity-United States, 1992. MMWR 1993;42:696-697,703.Google Scholar
2.Barnes, PFBloch, AB, Davidson, PT, Snider, DE Jr. Tuberculosis in patients with human immunodeficiency vims infection. N Engl J Med 1991;324:16441650.Google Scholar
3.Dooley, SW, Villarino, ME, Lawrence, M, et al. Nosocomial transmission of tuberculosis in a hospital unit for HIV-infected patients. JAMA 1992;267:26322635.Google Scholar
4.Pierce, JR Jr, Sims, SL, Holman, GH. Transmission of tuberculosis to hospital workers by a patient with AIDS. Chest 1992;101:581582.Google Scholar
5.Centers for Disease Control. Nosocomial transmission of multidrug-resistant tuberculosis to health-care workers and HIV-infected patients in an urban hospital-Florida. MMWR 1990;32:718722.Google Scholar
6.Centers for Disease Control. Nosocomial transmission of multidrug-resistant tuberculosis among HIV-infected persons-Florida and New York, 1988-1991. MMWR 1991;40:585591.Google Scholar
7.Edlin, BR, Tokars, JI, Grieco, MH, et al. An outbreak of multidrug-resistant tuberculosis among hospitalized patients with the acquired immunodeficiency syndrome. N Enngl J Med 1992;326:15141521.Google Scholar
8.Pearson, ML, Jereb, JA, Frieden, TR, et al. Nosocomial transmission of multidrug-resistant Mycobacterium tuberculosis. Ann Intern Med 1992;117:191196Google Scholar
9.Fischl, MA, Uttamchandani, RB, Daikos, GL, et al. An outbreak of tuberculosis caused by multipledrug-resistant tubercle bacilli among patients with HTV infection. Ann Intern Med 1992;117:177183.Google Scholar
10.Centers for Disease Control. Prevention and control of tuberculosis in migrant farm workers: recommendations of the Advisory Council for the Elimination of Tuberculosis. MMWR 1992;41(RR-10):115.Google Scholar
11.Centers for Disease Control. Prevention and control of tuberculosis in US communities with at-risk minority populations: recommendations of the Advisory Council for the Elimination of Tuberculosis. MMWR 1992;41(RR-5):111.Google Scholar
12.Centers for Disease Control. Prevention and control of tuberculosis among homeless persons: recommendations of the Advisory Council for the Elimination of Tuberculosis. MMWR 1992;41(RR-5): 1323.Google Scholar
13.Small, PM, Schecter, GF, Goodman, PC, Sande, MA, Chaisson, RE, Hopewell, PC. Treatment of tuberculosis in patients with advanced human immunodeficiency vims infection. N Eng UMed 1991;324:289294.Google Scholar
14.Centers for Disease Control and Prevention. Initial therapy for tuberculosis in the era of multidrug resistance: recommendations of the Advisory Council for the Elimination of Tuberculosis. MMWR 1993;42(RR-7):18.Google Scholar
15.Iseman, MD. Treatment of multidrug-resistant tuberculosis. N Engt J Med 1993;329:784791.Google Scholar
16.Centers for Disease Control. Guidelines for preventing the transmission of tuberculosis in health-care settings, with special focus on HIV-related issues. MMWR 1990;39(RR-17):129.Google Scholar
17.Centers for Disease Control and Prevention. Guidelines for preventing the transmission of tuberculosis in healthcare facilities, 1994. Federal Register 1994;59:5424254303.Google Scholar
18.US Department of Labor. Enforcement policy and procedures for occupational exposure to tuberculosis. Occupational Safety and Health Administration Enforcement Document, October 8,1993.Google Scholar
19.Riley, RL, Nardell, EA. Controlling transmission of tuberculosis in health care facilities: ventilation, filtration, and ultraviolet air disinfection. In: Plant Technology and Safety Management Series: Controlling Occupational Exposures to Tuberculosis. The Joint Commission on Accreditation of Healthcare Organizations 1993;No.1:2531.Google Scholar
20.Marier, RL, Nelson, T. A ventilation-filtration unit for respiratory isolation. Infect Control Hosp Epidemiol 1993;14:70@705.Google Scholar
21.Weber, A, Willeke, K, Marchioni, R, et al. Aerosol penetration and leakage characteristics of masks used in the health care industry. Am J Infect Control 1993;21:167173.Google Scholar
22.Chen, CC, Willeke, K. Aerosol penetration through surgical masks. Am J Infect Control 1992;20:177184.Google Scholar
23.Chen, CC, Willeke, K. Characteristics of face seal leakage in filtering facepieces. Am Ind Hyg Assoc J 1992;53:533539.Google Scholar
24.Brown, V, Bishop, C, Rutala, WA, Weber, DJ. HEPA respirators and tuberculosis in hospitals. N Engl J Med 1994;331:1659.Google Scholar
25.Moller, ARNoise as a health hazard. In: Last, JM, Wallace, RB, eds., Public Health and Preventive Medicine. 13th ed. Norwalk, CT: Appleton and Lange; 1992:523531.Google Scholar
26.Rhame, FS, Streifel, AJ, Kersey, JH, McGlave, PB. Extrinsic risk factors for pneumonia in the patient at high risk of infection. Am J Med 1984;76(5A):4252.Google Scholar
27.Opal, SM, Asp, AA, Cannady, PB, Morse, PL, Burton, IJ, Hammer, PG II. Efficacy of infection control measures during a nosocomial outbreak of disseminated Aspergillus associated with hospital constmction. Infect Dis 1986;153:634637.Google Scholar
28.Garner, JS, Simmons, BPCDC guideline for isolation precautions in hospitals. Infect Control 1983;4:248325.Google Scholar