10/27/2015 1 EXCELLENCE EXPERTISE INNOVATION Infection Prevention and Care in Corrections Part 2: Environmental Controls Shelly Robichaux, RN, MPH October 21, 2015 TB in Corrections: Best Practices for TB Prevention and Care October 21, 2015 Austin, TX • No conflict of interests • No relevant financial relationships with any commercial companies pertaining to this educational activity Shelly Robichaux, RN, MPH has the following disclosures to make:
Transcript
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EXCELLENCE EXPERTISE INNOVATION
Infection Prevention and Care in Corrections Part 2: Environmental Controls
Shelly Robichaux, RN, MPHOctober 21, 2015
TB in Corrections: Best Practices for TB Prevention and CareOctober 21, 2015
Austin, TX
• No conflict of interests
• No relevant financial relationships with any commercial companies pertaining to this educational activity
Shelly Robichaux, RN, MPHhas the following disclosures to make:
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Disclaimer
• This information should not be used in place of consultation with experts who can give advice on ventilation system design, selection, installation, and maintenance.
• Because environmental controls will fail if they are not properly operated and maintained, routine training and education of staff are key components to a successful TB infection‐control program.
Components of an Infection Control Program
Administrative Controls
•Screening
•Early diagnosis and treatment
•Isolation of contagious cases
Personal Protective Attire
•Surgical Mask
•N95 Mask
•FIT testing
Environmental Controls
•Ventilation
•Filtration
•UV lights
•Airborne Infection Isolation Rooms (AIIR)
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Tuberculosis Transmission
Tuberculosis Transmission
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Interrupting Tuberculosis Transmission
TB Infection
Active TB Disease
Transmission
Interrupting Tuberculosis Transmission
TB Infection
Active TB Disease
Transmission
Cure Active TB
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Interrupting Tuberculosis Transmission
TB Infection
Active TB Disease
Transmission
Cure Active TB Treat TB Infection
Interrupting Tuberculosis Transmission
TB Infection
Active TB Disease
Transmission
Cure Active TB Treat TB Infection
Environmental Controls
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Interrupting Tuberculosis Transmission
TB Infection
Active TB Disease
Transmission
Cure Active TB Treat TB Infection
Environmental Controls
THREE TYPES OF ENVIRONMENTAL CONTROLS
Most Effective Control
Ventilation
• Controls direction of air flow to prevent contamination of air in areas surrounding a person with infectious tuberculosis (TB)
• Dilutes and removes contaminated air
• Exhausts contaminated air to the outside
Supplementary Controls
High‐efficiency particulate air (HEPA) filtration
• Cleans the air of infectious droplet nuclei
Ultraviolet germicidal irradiation (UVGI)
• Kills or inactivates TB bacilli in the air
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Environmental Controls
Primary
Environmental Controls
• Natural ventilation (e.g., open doors, windows)
• Mechanical ventilation equipment to circulate and move air in a building
• Local exhaust ventilation (e.g., hoods, tents, or booths)
Environmental Controls
Primary
Environmental Controls
• Natural ventilation (e.g., open doors, windows)
• Mechanical ventilation equipment to circulate and move air in a building
• Local exhaust ventilation (e.g., hoods, tents, or booths)
Secondary
Environmental Controls
• Controls the airflow to prevent contamination of air in areas adjacent to the source (AII rooms)
• Cleans the air by using high efficiency particulate air (HEPA) filtration or ultraviolet germicidal irradiation (UVGI)
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Ventilation
• Ventilation is the movement of air in a building and replacement of inside air with air from the outside.
• Two general types of ventilation :– Natural ventilation, which relies on open doors and windows to bring in air from the outside. Fans may also assist in this process and distribute the air
– Mechanical ventilation, which usually refers to the use of mechanical air‐moving equipment that circulates air in a building and may also involve heating and/or cooling. Mechanical ventilation systems may or may not bring in air from the outside
Natural Ventilation
• Natural ventilation relies on cross ventilation in a building designed for good air exchange
• The use of open doors and windows to bring in air from outside
• Natural ventilation can be useful for nontraditional facility‐based and congregate settings that do not have a central ventilation system
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Natural Ventilation in TB Exam or Counseling Room
Mechanical Ventilation
• Mechanical ventilation refers to the use of equipment to circulate and move air in a building.
• Mechanical ventilation should be used by hospitals, TB clinics, and other health‐care and congregate settings expecting to see a confirmed or suspected TB patient.
• Mechanical ventilation consists of– Local exhaust ventilation– General ventilation
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Local exhaust ventilation
• Local exhaust ventilation stops airborne contaminants before they spread into the general environment.
• Local exhaust ventilation includes the use of:– External hoods– Booths– Tents
• Local exhaust ventilation should be used for cough‐inducing and aerosol‐generating procedures
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Local exhaust ventilation
• If local exhaust ventilation cannot be used, cough‐inducing and aerosol‐generating procedures should be performed in an airborne infection isolation (AII) room.
• If an AII room is not available, the procedures should be performed outdoors and away from:– People
– Windows
– Air intakes
General ventilation
• General ventilation systems maintain air quality in health‐care settings by the
– Dilution of contaminated air;
– Removal of contaminated air; and
– Control of airflow patterns in the patient’s procedure room or setting
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General ventilation
• Central ventilation systems, also called forced‐air systems, are mechanical systems that circulate air in a building. By providing fresh dilution air, a mechanical system can help prevent the spread of TB.
• However, the same system can inadvertently spread particles containing M. tuberculosis beyond the room occupied by the TB patient because it recirculates air throughout a building.
• Ventilation systems have been responsible for TB transmission among people who were never in the same room but shared air through a ventilation system.
HEPA Filtration
HEPA Filtration HEPA filtration can be used to supplement other recommended ventilation measures
• Only a HEPA filtration system will capture the small M. TB droplet nuclei.
• This air‐cleaning method is considered an adjunct to other ventilation measures.
• Used alone, this method does not provide the recommended ventilation measures.
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HEPA Filtration
UVGI: Ultraviolet germicidal irradiation
• UVGI is an air‐cleaning technology that consists of the use of special lamps that give off germicidal ultraviolet irradiation
• The lamps are used to inactivate the tubercle bacilli contained in the droplet nuclei.
• Overexposure to UV light can be harmful to the skin and eyes; lamps must be installed in the upper part of rooms or corridors or placed in exhaust ducts.
• Regular, appropriate maintenance is essential to ensure UVGI lamps are operating correctly
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UVGI: Ultraviolet germicidal irradiation
• UVGI lamps can be placed in ducts, fixed or portable room air‐recirculation units, or upper‐air irradiation systems.
• The use of this air‐cleaning technique has increased, particularly in substantial open areas in which unsuspected or undiagnosed patients with TB disease might be present
– Common Rooms
– Waiting Rooms
• Not for use in high humidity areas such as shower rooms or open air rooms in climates with high humidity.
UVGI
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UVGI: Ultraviolet germicidal irradiation
AIIR: Airborne Infection Isolation Rooms
• Persons who have or are suspected of having infectious TB disease should be placed in an area away from other patients, preferably in an airborne infection isolation (AII) room.
• An AII room is a single‐occupancy patient‐care room in which environmental factors are controlled to minimize transmission of infectious agents.
• If a facility does not have an AII room, patients should be placed in a room that has been designated for isolation of persons with suspected or known infectious TB disease and, if possible, referred to a facility with an AII room.
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AIIR: Airborne Infection Isolation Rooms
• Whenever an AIIR is used, written policies and procedures should be developed and implemented to address the administrative aspects of the AIIR.
• They should include:
– criteria for initiating and discontinuing isolation
– who has authority for initiating and discontinuing isolation
– isolation practices
– how often and by whom the policy and procedure is evaluated
AIIR: Airborne Infection Isolation Rooms
• One characteristic of AII rooms is their negative pressure relative to other parts of the facility.
• Negative pressure causes air to flow from the corridors into the AII room.
• The air from the AII room cannot escape to the other parts of the facility when the door is closed and the ventilation system is operating properly.
• The doors and windows of AII rooms must be kept closed as much as possible in order to maintain negative pressure, and the pressure must be checked periodically to make sure that it remains negative.
Negative Pressure
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AIIR: Airborne Infection Isolation Rooms
• Air from the AII room can be exhausted directly to the outdoors, where the droplet nuclei will be diluted in the outdoor air, or
• Passed through a special high efficiency particulate air (HEPA) filter that removes most (99.97%) of the droplet nuclei before it is returned to the general circulation.
• If a HEPA filter is not used, the air should be exhausted directly to the outside away from air‐intake vents, persons, and animals, in accordance with applicable federal, state, and local regulations on environmental discharges.
Negative Pressure
AIIR: Airborne Infection Isolation Rooms
Air flows from an area of high pressure to low
pressure
A room under negative
pressure has a lower pressure than adjacent
areas
Air is drawn into the room; negative
pressure directs the airflow
Negative pressure is achieved by
exhausting more air from a room than is supplied
Negative pressure keeps droplet nuclei in the room
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Air Washout Times
TABLE 1. Air changes per hour (ACH) and time required forremoval of airborne contaminants, by efficiency percentage
Minutes required for removal
ACH 99.0% efficiency 99.9% efficiency
2 138 207
4 69 104
6 46 69
12 23 35
15 18 28
20 7 14
50 3 6
CDC. MMWR 2006; 55(RR-9):12
AIIR: Airborne Infection Isolation Rooms
When feasible, the airflow in existing health‐care setting AII rooms should be increased to 12 ACH by
• Adjusting or modifying the ventilation system;
• Using air‐cleaning methods:
– room‐air recirculation units containing HEPA filters or
– ultraviolet germicidal irradiation (UVGI) systems that increase the equivalent ACH.
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Airborne Infection Isolation Room
AIIR: Airborne Infection Isolation Rooms
AII rooms should be checked for negative pressure by using smoke tubes or other visual checks before occupancy, and
Rooms should be checked daily when occupied by a patient with suspected or confirmed TB disease.
Daily functional test while in use, monthly if not in use
Tissue (flutter) test
Smoke tube
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Functional test of AII room
Components of an Infection Control Program
Administrative Controls
Personal Protective Attire
Environmental Controls
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Questions…
References• CDC. Guidelines for preventing the transmission of Mycobacterium tuberculosis in
• Prevention and control of tuberculosis in correctional and detention facilities: Recommendations from CDC. MMWR 2006; 55 (No. RR‐09): 1– 44. – www.cdc.gov/mmwr/preview/mmwrhtml/rr5509a1.htm
• Curry International Tuberculosis Center (US). Tuberculosis Infection Control: A Practical Manual for Preventing TB; 2007.– http://www.currytbcenter.ucsf.edu/products/tuberculosis‐infection‐control‐practical‐
manual‐preventing‐tb
• Core Curriculum on Tuberculosis: What the Clinician Should Know ‐ Chapter 7: Tuberculosis Infection Control.– http://www.cdc.gov/tb/education/corecurr/pdf/chapter7.pdf
