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Circular 95-09-C


[Please note:  This model exposure control plan is intended to be adjusted to meet the needs of the local program.  Sections should be added, deleted or modified as required.]

INDIAN HEALTH SERVICE
________________________________________
[Area, Service Unit, or Facility Name]

TUBERCULOSIS EXPOSURE CONTROL PLAN

This Exposure Control Plan (ECP) applies to all employees, volunteers, and students in the- ___________________________________ [name of area, service unit, or facility] including Federal employees assigned to Public Law 93-638 facilities.

  1. PURPOSE.  The purpose of this ECP is to eliminate or reduce as much as possible, employee, patient, and visitor exposure to Mycobacterium (M.) tuberculosis (TB).
  2. BACKGROUND.  Since 1985, the rate of new cases of tuberculosis in the general U.S. population increased 18 percent, reversing a 30-year downward trend.  As the incidence of TB increased, occupational exposure among HCWs also increased. Nationally, during this time period, several hundred employees were infected from work place exposure to TB requiring medical treatment. Sixteen HCWs developed active multi-drug resistant tuberculosis (MDR-TB).  There were at least five health, care workers (HCW) deaths due to MDR-TB.  Drug resistant strains of TB are now a serious concern with cases being reported in forty states.

    Due to the resurgence of TB and the dangers associated with drug resistant strains, the Centers for Disease Control and Prevention (CDC) and the Occupational Safety and Health Administration (OSHA) published guidelines and enforcement actions related to TB.  OSHA issued its "Enforcement Policy and Procedures for Occupational Exposure to Tuberculosis" in October, 1993. CDC "Guidelines for Preventing the Transmission of Tuberculosis in Health care Facilities, 1994" were published in the October 28, 1994, Federal Register.  The OSHA enforcement policy was based on the earlier 1990 CDC guidelines; however, it is likely that OSHA will begin citing the more recent CDC guideline.  OSHA utilizes the "General Duty Clause" (section 5-a-1) of the Occupational Safety and Health Act to enforce these policies and procedures.  While many health care facilities have components of a TB prevention program, the CDC and OSHA documents are now forcing a consistent, comprehensive approach.  This TB ECP is intended to meet that need.  Effective January 8, 1994, the OSHA began enforcing the requirement that HCWs wear High Efficiency Particulate Air (HEPA) respirators when potentially exposed to TB.  The circumstances which OSHA considers as potential exposures are relatively well defined in their enforcement policy and in this document.

  3. EPIDEMIOLOGY, TRANSMISSION, AND PATHOGENICITY OF TB.  TB is not evenly distributed throughout all segments of the U.S. population.  Some subgroups or individuals have a higher risk of TB either because they are more likely than the general population to have been exposed to and infected by TB or because they are more likely to progress to active TB once infected. In some cases, both of these factors may be present.

    Suspect populations include: Native Americans, immigrants from countries with high incidence of TB, homeless persons, past/current prison inmates, alcoholics, intravenous drug users, the elderly, and contacts of persons with active TB.  Persons with higher incidence of progression from latent to active TB include persons with such medical conditions as: Human Immunodeficiency Virus (HIV) infection, silicosis, post gastrectomy, jejuno-ileal bypass surgery, being 10 percent less than ideal weight, chronic renal failure, diabetes mellitus, immunosuppression due to high doses of immunosuppressive therapy, and some malignancies.  Also included are those: infected with TB within the last two years, children less than 3 years, and persons with fibrotic lesions on chest radiographs.  Symptoms of TB include:  a cough lasting 2 weeks or greater, bloody sputum, night sweats, weight loss, anorexia, and fever.

    The TB organism is carried in airborne particles known as droplet nuclei, that can be generated when persons with pulmonary or laryngeal TB sneeze, cough, speak, or sing.  The particles are estimated to be approximately 1-5 microns in size, and normal air currents keep them airborne and can spread them throughout a room or building. Infection occurs when a susceptible person inhales droplet nuclei containing TB, and bacilli are able to traverse the mouth or nasal passages, upper respiratory tract, and bronchi to reach the alveoli of the lungs.  Once in the alveoli, the organisms are taken up by a alveolar macrophage and spread throughout the body.  Usually within 2 to 10 weeks after initial infection with TB, the immune response limits further multiplication and spread of the tubercle bacilli; however, some of the bacilli remain dormant and viable for many years.  This is known as latent TB infection.  Persons with latent TB infection usually have a positive purified protein derivative, (PPD) skin test, no symptoms of active TB, and are not infectious.  In general, persons with latent TB infection have approximately a 10% risk during their lifetime for the development of active TB.  The risk is greatest in the first 2 years after infection, but some risk persists for decades.

    Persons with immunocompromising conditions have a greater risk for the progression of latent TB infection to active disease.  The HIV is the strongest known risk factor yet identified for the progression from latent TB infection to active TB disease.  Persons with latent TB infection who become infected with HIV have approximately an 8 to 10 percent risk per year for the development of active TB.  Persons who are infected with HIV and become newly infected with TB have an even greater risk for the development of active TB.

    The probability that a susceptible person will become infected with TB depends primarily upon the concentration of infectious droplet nuclei in the air and the duration of exposure.  Characteristics of the TB patient that enhance transmission include:  (1) Disease in the lungs, airways, or larynx, (2) presence of cough or other forceful expiratory measures, (3) presence of acid-fast bacilli (AFB) in the sputum, (4) failure of the patient to cover the mouth and nose when coughing or sneezing, (5) presence of cavitation on chest radiograph, (6) short duration of adequate chemotherapy, and (7) administration of procedures that can induce coughing or cause aerosolization of TB (e.g., sputum induction, administration of aerosolized medication, etc.).  Environmental factors that enhance the likelihood of transmission include:  (1) exposure of susceptible persons to an infectious person in relatively small enclosed spaces, (2) inadequate local or general ventilation that results in insufficient dilution and/or removal of infectious droplet nuclei, and (3) recirculation of air containing infectious droplet nuclei.

  4. FACTORS IN NOSOCOMIAL TRANSMISSION OF TB. The transmission of TB is a recognized risk in health care facilities.  The magnitude of the risk varies considerably by type of health care facility, prevalence of TB in the community, patient population served, job category, area of the health care facility in which a person works, and the effectiveness of TB infection control interventions.  The risk may be higher in areas where patients with TB are provided care before diagnosis and initiation of TB isolation precautions (e.g. clinic waiting areas and emergency rooms) or where diagnostic or treatment procedures that stimulate coughing are performed.  Nosocomial transmission of TB has been associated with close contact with infectious patients or HCWs and during procedures such as bronchoscopy, endotracheal intubation and suction, open abscess irrigation and autopsies.  Sputum induction and aerosol treatments that induce cough may also increase the potential for TB, transmission.  Health care personnel should be particularly alert to the need for preventing TB transmission in health care facilities in which immunocompromised persons, such as persons with HIV infection, receive care and/or work.

    Several TB outbreaks in health care facilities have been reported during the past several years.  Some of these outbreaks involved transmission of MDR strains of TB to both patients and HCWs.  Most of the patients and some of the HCWs were HIV infected persons in whom new infection progressed rapidly to active disease.  Mortality associated with those outbreaks was very high (range 43 to 93 percent).

    Furthermore, the time between diagnosis and death was very short with the median interval ranging from 4 to 16 weeks.  Factors contributing to these outbreaks included delayed diagnosis of patients with TB, delayed recognition of drug resistance, delayed initiation of effective therapy resulting in prolonged infectiousness, delayed initiation and inadequate duration of TB isolation, inadequate ventilation in TB isolation rooms, lapses in TB isolation practices, and inadequate precaution for cough inducing procedures.  There is evidence from three of the facilities that MDR-TB transmission decreased significantly or ceased in areas where measures similar to those provided in this ECP were implemented.

  5. RISK ASSESSMENT.  A risk assessment of ___________________________________ [list/name of the facility/clinic] shall be completed by the designated TB control [specify either: officer, physician, or committee] at least once every three years, or more frequently if the incidence of TB in the community has changed or there has been a change in procedures or facility design that may increase the risk of TB exposure.  The risk assessment may be conducted of the entire facility or may assess individual areas (or occupational groups) in the institution. Historical information (prevalence of TB in service area, number of TB patients encountered in each setting, and HCW PPD skin test conversions) was used to classify tasks/procedures as to level of risk.  The TB control measures outlined in section 6 are based on this risk assessment.  Based on the assessment, _________________________ [specify the: facility, area(s), or occupational group(s)] is/are classified as [specify:  high, intermediate, low, very low, or minimal] risk.
    1. Policies and Procedures.

      Policies and procedures (P&P) were reviewed to ensure that appropriate administrative TB control measures were being followed.  These administrative measures include staff training on early identification, appropriate isolation, rapid access to lab tests/results, mandatory skin testing program, and appropriate treatment of TB patients.  These policies and procedures (TB skin testing policy, AFB isolation, and etc._________________________) [list the P&P related TB] are located at:

      _________________________________________________________________
      [list where P&P are kept].

    2. High risk Procedures.

      High risk procedures conducted at the facility or conducted by HCWs at other sites (home care, ambulance, etc.) were identified and include [list high risk procedures, location, and staff involved.  Examples are given]:

      High Risk Task Location of Task Staff Involved
      Sputum Induction Room #________________ RN, RT
      Bronchoscopies Room #________________ RN, MD,
      Isolation rooms Room #s_______________ Nur, MD, Hskp,
      Aerosolized drugs Room #s_______________ Nur, Resp Ther,
      Sputum Induction Home Care _____________ CHRs & RN
      Other [Specify] _______________________ ________________
      ________________ _______________________ ________________
      ________________ _______________________ ________________
    3. Respiratory Protection Program.

      The respiratory protection program was reviewed to ensure that staff exposed to high risk situations (see above) were appropriately protected.  This assessment included identifying situations/tasks that require use of respiratory protection, identifying employees (by job category) that are required to perform those tasks, and review of the respirator assignment program (medical evaluation, fit testing, training, care, and replacement) to ensure that it meets minimal requirements (29 CFR 1910.134).

    4. Engineering Controls.

      Engineering controls used to reduce exposure to TB were identified and evaluated to determine if they provide adequate protection.  The engineering controls used in this facility include [list all engineering controls used and their location]:

      Engineering Control Location [Specify building, room number, air handling unit, etc.]
      Isolation Rooms_________________ ______________________________
      Sputum Induction Booth(s) ______________________________
      Biological Safety Cabinet ______________________________
      HEPA Filters______________________ ______________________________
      Other [Specify]____________________ ______________________________
      ________________________________ ______________________________
  6. EXPOSURE CONTROL PROCEDURES.

    There are three approaches to effectively controlling exposure to TB which are used in this ECP.  In order of importance, these methodologies are administrative controls (rapid detection, isolation, and treatment), engineering controls (control of air flows, filtering recirculated air, direct discharge of exhaust air), and respiratory protection (HEPA respirator use).

    1. Early Detection of Patients With TB.  The HCWs who are the first points of contact (emergency rooms outpatient clinics, inpatient admissions, home health) in serving patients at risk for TB shall:
      1. Be familiar with the signs and symptoms associated with TB (TB should be considered in any patient with a persistent cough greater than (>) 2 weeks duration, bloody sputum, night sweats, weight loss, anorexia, and/or fever).
      2. Be trained to ask appropriate questions which will help recognize and detect patients with signs and symptoms suggestive of TB.
      3. Ensure patients with signs or symptoms suggestive of TB are evaluated promptly to minimize the time spent in ambulatory care areas.  Such patients shall have TB precautions applied while the diagnostic evaluation is being conducted.
      4. Diagnostic measures should be used on patients suspected of having TB.  Immunosuppressed patients with pulmonary signs or symptoms that are initially ascribed to other etiologies should be evaluated for co-existing TB initially, and the evaluation should be repeated if the patient does not respond to appropriate therapy for the presumed etiology.  These diagnostic measures typically include:
        1. Obtaining an appropriate history (medical, social, etc.), conducting a physical examination, PPD skin testing, chest radiograph, and microscopic examination and culture, of sputum or other specimens.
        2. Other diagnostic methods, such as bronchoscopy or biopsy, may be indicated for some patients.

        Laboratories shall use the most rapid methods available.  Results of AFB smears of sputum should be available from the lab conducting the test within 24 hours of receiving the specimen.

    2. Management of Outpatients With Possible TB.

      The following precautions shall be implemented when a patient suspected or known to have infectious TB is seen in the ambulatory care setting.

      1. The patient will be placed in a separate waiting area apart. from other patients and not in open waiting areas, ideally, in a negative pressure room.
      2. In the outpatient area room # ____ [list room #] is the designated TB treatment room and in the emergency room area room # _____ [list room #] is the designated TB treatment room.
      3. Staff are required to wear a HEPA respirator when entering the room where the patient is located.  The patient will wear a surgical mask, especially if they are transported to a different location in the facility.  Family members who must be in the room should also be asked to wear a surgical mask.  If possible, the patient will not leave this designated room(s) for any procedures unless absolutely necessary.  Access to the room for both staff and family shall be limited to essential persons only.
      4. Patients are to be given tissues and instructed to cover their mouths and noses when coughing or sneezing.
      5. Patients with known active TB who need to be seen in a clinic shall have appointments scheduled to avoid exposing HIV-infected or otherwise severely immunocompromised persons.
      6. When high risk procedures (sputum induction, administration of aerosolized medication, etc.) are conducted on patients known or suspected of having infectious TB, those procedures shall be conducted in one of the sputum collection booths/enclosures located in room #____ or ____ [list room #s].  Sputum collection booths or other local exhaust devices used to prevent spread of TB shall be ventilated appropriately. See Section 6 for ventilation requirements.
      7. Most patients with infectious TB can be treated as outpatients, since close contacts have already been exposed and treatment rapidly reduces infectivity.  Patients with active TB should receive directly observed therapy, whenever possible, to insure compliance with recommended treatment.  Hospitalization may be indicated if the patient has other medical problems, or if there are problems in initiating directly observed therapy as an outpatient.  Treatment for active tuberculosis greatly reduces the infectivity over a two to three week period.  Use of masks can be discontinued when the patient has had three sputa negative or smear for AFB collected on three different days.
    3. Isolation for Infectious Inpatient With TB.

      Any inpatient suspected or known to have infectious TB shall be placed in AFB isolation in a private room.  The room shall meet the CDC criteria for AFB isolation rooms.  See Section 6 for AFB isolation room requirements.

      The following rooms are designated as AFB isolation room [list wrd and room #s].

      ______________________ ward, rooms ____, ____, and ____.
      ______________________ ward, rooms ____, ____, and ____.
      ______________________ ward, rooms ____, ____, and ____.
      ______________________ ward, rooms ____, ____, and ____.

      AFB isolation practices shall, at a minimum, include the following:

      1. Patients who are placed in AFB isolation shall be educated about the transmission of TB and the reasons for TB isolation.  They shall be taught to cover their mouth and nose with a tissue when coughing or sneezing, even while in the TB isolation room.
      2. Patients in AFB isolation shall remain in the isolation room with the door closed whenever possible.  Diagnostic and treatment procedures shall be performed in the isolation room whenever possible to avoid transportation of the patient throughout the institution.  If a patient who may have infectious TB must be transported outside the TB isolation room for a medically essential procedure that cannot be done in the room, he/she shall wear a surgical mask covering the mouth and nose (unless the medical condition prohibits use of a mask).  Procedures should be scheduled at a time when they can be performed rapidly and when waiting areas are less crowded.
      3. Efforts should be made to facilitate patient adherence to TB isolation measures, such as staying in the room.  Such efforts might include the use of incentives, such as providing telephones, televisions, VCRs, or radios in the room.
      4. The number of persons entering the AFB isolation room shall be kept to a minimum.
      5. AFB isolation rooms should be prioritized to be used for patients with conditions requiring respiratory isolation with TB being a top priority.
      6. When high risk procedures (sputum induction, administration of aerosolized medication, etc.) are conducted on patients known or suspected of having infectious TB those procedures shall be conducted in one of the sputum collection booths/enclosures located in room # ____ or ____ [list room #s].  See Section 6 for ventilation requirements associated with use of booths/enclosures.
      7. Rooms occupied by a highly suspect or known active TB patient shall have a sign posted at the door reading "AFB Isolation", "HEPA Respirator Required For Entry".
      8. AFB isolation rooms shall be checked periodically for negative air pressure and direction of air flow when occupied by a patient with known or suspected to have infectious TB.  Checking of the negative air pressure can be discontinued when AFB isolation is discontinued.
      9. AFB isolation is discontinued only when the patient is on effective therapy, is improving clinically, and the sputum smear is negative for AFB for three consecutive days or the diagnosis of TB has been ruled out.
      10. Because of the need for isolation procedures, patients with tuberculosis feel ostracized and may not comply with recommended therapy.  Special efforts must be made to educate patients them about the solation requirements and to reassure them that they will likely be cured of their disease, if they comply with the recommended treatment.
      11. The following inpatient facilities within the [name] Area have been identified as meeting the OSHA standards for treatment of contagious TB patients (list available IHS and non-IHS referral hospitals).

        ____________________________________________________________
        ____________________________________________________________
        ____________________________________________________________

    4. Environmental/Engineering Control.

      Environmental/engineering controls are used to reduce or eliminate TB droplet nuclei in the air.  Ventilation systems for health care facilities shall be designed, and modified when necessary, by ventilation engineers in collaboration with infection control and occupational health staff.

      The IHS Division of Facility Planning and Construction (DFPC) provides guidance on the design and operation of health care facilities.  The IHS "Health Facilities Planning Manual" shall be used when new facilities are built or when existing facilities are renovated to ensure ventilation requirements are met.

      Engineering controls designed to reduce or eliminate TB droplet nuclei in the air include:

      1. Local Exhaust Ventilation - booths/tents/hoods.

        The booth or enclosure shall maintain negative pressure in relation to the surrounding room or area.  It shall have a minimum of 20 air changes per hour (ACH), and air exhausted from the booth or enclosure shall be directed to the outside of the building, away from air-intake vents, people, and animals.  Alternatively, the air may be HEPA filtered prior to recirculation.

        1. Air Flow Direction/Pressure Differential.

          The booth/hood/tent exhaust fan shall be located on the discharge side of the HEPA filter.  This will maintain negative pressure in the booth with respect to adjacent areas.

        2. Exhaust Time Prior to re-use/cleaning.

          Booths, tents, or hoods used for cough inducing treatments shall be equipped with exhaust fans that have sufficient air flow capacity to remove greater than 99 percent of airborne particles during the time interval between the departure of one patient and the arrival of the next or before cleaning or maintenance activities are performed on the unit.  A minimum of _____ [clearance time to be determined by an Industrial Hygienist or other qualified individual] minutes shall be allowed between patients or before cleaning/maintenance of the unit.  Staff who enter the booth/enclosure prior to this clearance time shall be required to use a HEPA respirator.

      2. Negative Pressure Rooms (Outpatient/TB Treatment Rooms).
        1. Air Flow Direction/Pressure Differential.

          Outpatient used to examine or treat suspected or confirmed TB patients shall maintain a negative pressure in relation to surrounding rooms.  The pressure differential shall be at least 0.001 inches of water, measure at the base of the room door.  [To achieve negative pressure, the ventilation system shall exhaust 10% or 50 cubic feet per minute more air, whichever is greater, than the amount of air supplied to the room.]

        2. Minimum Air Chancres per Hour.

          These rooms shall have a minimum of six ACH in existing facilities, and at least twelve ACH in newly constructed or renovated rooms.  Exhaust from the rooms shall be directed to the outside of the building, away from air-intake vents, people, and animals, or be HEPA filtered prior to recirculation.

      3. Isolation Rooms (Inpatient Only).
        1. Air Flow Direction/Pressure Differential.

          The ventilation system shall be designed and balanced to provide air flow patterns from hallways/adjacent areas to the isolation room.  A pressure differential of 0.001 inch of water, measured at the base of the room door is required.

          Negative pressure shall be achieved by balancing the room supply and exhaust flows by setting the exhaust flow to a value 10 percent (but no less than 1,415,815 cubic centimeters (50 cubic feet) per minute (cfm)) greater than the supply.  Negative pressure in a room can be altered by small changes in the ventilation system operation, or by the opening and closing of the isolation room, corridor doors, or windows.  It is, therefore, essential that once an operating configuration has been established, all doors and windows remain appropriately closed in both the isolation room and other areas, except when needed to enter or leave an area.

        2. Minimum Air Changes per Hour.

          These rooms shall have a minimum of six ACH in existing facilities, and at least twelve ACH in newly constructed or renovated rooms.  Exhaust from the rooms shall be directed to the outside of the building, away from air-intake vents, people, and animals, or be HEPA filtered prior to recirculation.

        3. Private Rooms.

          Rooms used for AFB isolation shall be single-patient rooms with negative pressure relative to the corridor or other areas connected to the room.  Doors between the isolation room and other areas shall remain closed except for entry or egress.

          Toilet, bathtub (or shower), and hand washing facilities are required for each isolation room.  These shall be arranged to permit access from the bed area without the need to enter or pass through the work area of the vestibule or anteroom.

        4. Anterooms.

          If provided, anteroom ventilation systems shall be designed and balanced to provide air flow patterns from hallways/adjacent areas to the anteroom and from the anteroom to the isolation room.  A pressure differential of 0.001 inch of water, measured at the base of the doors, is the minimum acceptable levels from the hallway/adjacent areas to the anteroom and from the anteroom to the isolation room.  A single anteroom may serve more than one isolation room.

          Negative pressure shall be achieved by balancing the room supply and exhaust flows by setting the exhaust flow to a value 10 percent (but no less than 50 cfm) greater than the supply.

          The anteroom shall be equipped with both a supply and exhaust vent.  A minimum of 10 ACH shall be provided to the anteroom.

          Alternates for Negative Pressure

          Note:  [Recirulation of HEPA filtered air in a room can be achieved by (1) recirculation of air exhausted from the room into a duct, filtered with an in-duct HEPA filter, and returned to the room or (2) in-room wall-mounted or portable HEPA filters.  Room recirculation will permit higher air flow rates than can be normally achieved with general ventilation, since the air does not have to be conditioned, other than filtered.  Effectiveness is dependent upon all the air in the room circulating through the HEPA filter, which can be difficult to achieve and evaluate.  Portable HEPA filtration units may be considered for areas where there is no general ventilation system or where the system is incapable of providing adequate air flow.

          If these units are used, caution should be exercised to assure that they can recirculate all or nearly all of the room air through the HEPA filter.  Portable HEPA filtration units have not been evaluated adequately to determine their role in TB exposure control programs.  Therefore, these units should not substitute for other, more established measures, except for short-term intervention while other engineering controls are being implemented.]

      4. Dilution Ventilation.

        Dilution ventilation reduces the concentration of contaminants in a room by supplying air that does not contain those contaminants.  The supply air mixes with and then displaces some of the contaminated room air, which is subsequently removed from the room by the exhaust system.  Dilution ventilation can be achieved using two types of systems; single pass or recirculating systems.

        1. Air Flow Direction/Pressure Differential.

          General ventilation systems shall be designed to (1) prevent stagnation of the air and (2) prevent short circuiting of the supply to the exhaust.  The general ventilation system shall be designed and balanced to provide air flow patterns from more clean to less clean areas, such as from hallways to treatment rooms or corridors to patient rooms.  The direction of air flow is controlled by creating a lower pressure in the area into which flow is desired (a minimum of 0.001 inches of water).  Negative pressure is attained by exhausting air from the area at a higher rate than it is being supplied.

        2. The ACH and Recirculation.

          The IHS "Health Facilities Planning Manual" will be followed concerning the minimum ACH and percentage of recirculation for all general use areas.

      5. Direct Discharge & HEPA Filtration.

        The air discharged from AFB isolation rooms, anterooms, negative pressure TB treatment rooms, booths, tents, and hoods shall be exhausted directly to the outside of the building, away from air-intake vents, people, and animals, in accordance with federal, state, and local regulations concerning environmental discharges.

        Note:  [Design guidelines for proper placement can be found in the 1989 ASHRAE Fundamentals Handbook.  If direct exhaust to the outside is impossible, air from isolation rooms, booths, tents, and hoods should only be exhausted within the facility through Properly designed, installed, and maintained HEPA filter.  As an additional safety measure, air may be discharged to the outside through HEPA filters to preclude reentry of air containing infectious droplet nuclei into the ventilation supply.  This is especially desirable if the exhaust discharge cannot be extended to the roof.)

      6. Periodic Maintenance/Testing of Controls.

        The __________________________________ [list the department responsible] shall develop, implement, and document a maintenance program that will ensure that the environmental/engineering control implemented to reduce exposure to TB operate properly.  The maintenance program shall include as a minimum the following items:

        1. Initial and thereafter quarterly evaluation of each isolation room, anteroom, booth, tent, or hood/enclosure for ACH, and direction and velocity of air flow into the space.
        2. Periodic testing, when in use, of each isolation room, anteroom, booth, tent, or hood/enclosure for negative pressure.
        3. Initial determination of the location of exhaust discharge to ensure the exhaust from isolation rooms, anterooms, booths, tents, and hoods/enclosures is not discharged near an intake source or area where the public or employees will be exposed.
        4. Monitoring of the equipment and HEPA filtering apparatus as recommended by the manufacturer.  A quantitative leakage and filter performance test using the dioctal phthalate (DOP) penetration test shall be performed at the initial installationof a HEPA filter and whenever the HEPA filter is changed or moved.  A manometer or other pressure sensing device shall be installed in the filter system to provide an accurate means of objectively determining the need for filter replacement.  Pressure drop characteristics of the filter are supplied by the manufacturer.  Installation shall allow for maintenance without contaminating the delivery system or the area served.  The "bag in, bag out" method used for changing filters in systems containing carcinogens shall be used.  Because of the potential risk of infection to staff who perform this maintenance, it shall be performed only by personnel who are adequately trained.  Appropriate respiratory protection shall be worn during maintenance and testing.  In addition, filter housing and ducts leading to the housing shall be clearly marked "Contaminated Air".
    5. Respiratory Protection.

      All HCWs who enter a TB isolation room, booth, or other space (including vehicles used to transport patients) where known or suspected TB patients are receiving care shall be supplied with and wear a particulate respirator that meets recommended performance criteria and requirements of CDC and OSHA.  The respiratory protection program shall comply with the requirements set forth in 29 CFR 1910.134.

      1. Employee Requirements.

        All HCWs required to use respiratory protection shall be included in this program.  The respiratory protection program shall, at a minimum, include:

        1. Assignment of responsibility: Supervisory responsibility for the respiratory protection program shall be assigned to _____________________ [list the person/position responsible].
        2. Procedures:  Written procedures shall contain information on all aspects of the respiratory protection program.
        3. Medical Screening:  The HCWs shall not be assigned a task requiring use of respirators, unless they are physically able to do the work while wearing the respirator.  The HCWs shall be screened for pertinent medical conditions upon employment and periodically rescreened.
        4. Training:  Respirator wearers and supervisors shall receive training in the reasons for the need for wearing their respirator and the potential risks of not doing so.  This training shall also include an explanation of the operation, capabilities, and limitations of the respirator provided.
        5. Face-Seal Fit Testing and Fit Checking:  The HCWs shall undergo fit testing to identify a respirator with an adequate fit for that HCW.  The HCW shall receive fitting instructions including demonstrations and practice in how the respirator should be worn, how to adjust it, and how to determine if it fits properly.  The HCW shall be instructed to check the face piece fit before each use.
        6. Respirator Inspection, Cleaning, Maintenance, and Storage:  Respirator maintenance shall be made an integral part of the overall respirator program.  Manufacturers' instructions for inspection, cleaning, and maintenance of respirators shall be followed to ensure that the respirator continues to function properly.  The respirators shall be stored in accordance with CRF 1910.134 (B) (6) in a convenient, clean, and sanitary location.
        7. Periodic Evaluation of the Personal Respiratory Protection Program.  The program shall be completely evaluated at least annually, and both the written operating procedures and program administration shall be modified as necessary based on the results.  Elements of the program that shall be evaluated include work practices and acceptance of respirators, including comfort and interference with duties.  The evaluation of the use and maintenance of respirators shall be included as a part of the facility hazard surveillance program.
      2. Respirator Performance Criteria.

        Respiratory protective devices used by employees for TB shall meet the OSHA respiratory protection standard.

        Note:  Respirators with HEPA filters are the only currently available certified respirators that meet the OSHA standard.  The National Institute of Occupational Safety and Health is in the process of creating a certification standard for respirators with a 95% efficiency for removal of particles 1u or smaller.  When the certification standard is complete, the 95% respirators should be used.

      3. Indicators For Use.

        Appropriate respiratory protection shall be worn by persons potentially exposed to TB in settings where administrative and engineering controls may not provide adequate protection.  Such settings include TB isolation rooms and rooms in which patients who may have infectious TB are undergoing cough inducing or aerosol generating procedures (irrigation of tuberculoses abscesses, performing bronchoscopies, sputum induction, etc.), and the transport of patients who may have infectious TB in emergency transport vehicles.  Every attempt will be made to prevent occupational exposure using engineering or administrative controls before requiring the use of respirators.

      4. Patients.

        Patients with active TB or those suspected to have active TB shall be required to wear a surgical mask while in the facility, unless they are in a TB isolation room.

      5. Visitors.

        The number of visitors allowed shall be kept to an absolute minimum during the time period when the patient is considered infectious.  Individuals who visit a patient with active TB shall be notified that they should wear respiratory protection during the time they are in the patient's room.  At a minimum surgical masks shall be available for use by those individuals visiting patients with active TB.

    6. Cough-Inducing Procedures.

      Procedures that involve instrumentation of the lower respiratory tract or induce cough may increase the probability of droplet nuclei being expelled into the air.  These cough inducing procedures include endotracheal intubation and suctioning, diagnostic sputum induction, aerosol treatments, and bronchoscopy.  The following methods shall be followed when cough inducing procedures are conducted on individuals that have or are suspected of having TB:

      1. Cough inducing procedures shall be performed on patients who may have infectious TB using local exhaust ventilation devices (e.g., booths or special enclosures) or in a room that meets the ventilation requirements for TB isolation.
      2. Patients shall remain in the isolation room or enclosure and not return to common waiting areas until coughing subsides.  They shall be given tissues and instructed to cover their mouth and nose when coughing or sneezing.
      3. Before the booth, enclosure, or room is used for another patient, __________ [clearance time to be determined by an Industrial Hygienist or other qualified individual] minutes shall be allowed to pass so that any droplet nuclei that have been expelled into the air are removed.
    7. Staff Training and Education.

      All HCWs shall receive education about TB that is appropriate to their job category.  Training shall be conducted before initial assignment and subsequently on a periodic basis.  Although the level and detail of this education may vary according to job description, the following information should be included in the education of all HCWs:

      1. The basic concepts of TB transmission, pathogenesis, and diagnosis, including the difference between latent TB infection and active TB disease, the signs and symptoms of TB, and the possibility of reactivation in persons with a positive PPD test.
      2. The potential for occupational exposure, the prevalence of TB in the community and facility, the ability of the facility to appropriately isolate patients with active TB, and situations with increased risk of exposure to TB.
      3. The principles and practices of infection control that reduce the risk of transmission of TB.
      4. The purpose of a PPD testing program.
      5. The principles of preventive therapy for latent TB infection.  Indications, use, and effectiveness, including the potential adverse effects of the drugs.
      6. The responsibility of the HCW to seek medical evaluation promptly if symptoms develop that may be due to TB.
      7. The principles of drug therapy for active TB.
      8. The importance of notifying the facility if diagnosed with active TB so appropriate contact investigation can be instituted.
      9. The responsibilities of the facility to maintain the confidentiality of HCWs diagnosed with TB while assuring appropriate therapy is received.
      10. The higher risk posed by TB to individuals with HIV infection or other causes of severely impaired cell-mediated immunity.
      11. The potential development of cutaneous anergy as immune function measured by CD4 + T-lymphocyte counts, declines.
      12. The facility's policy on voluntary work reassignment options for immunocompromised HCWs should be explained.
    8. The HCWs Counseling and Screening.

      Individuals with HIV or others with impaired cell-mediated immunity are at a higher risk of developing active TB.  Counseling of these employees shall include information on the following:

      1. More frequent and rapid development of clinical TB after infection.  Because of the increased risk of rapid progression from latent TB infection to active TB in HIV-positive or otherwise severely immunocompromised persons, all HCWs should know if they have a medical condition or are receiving a medical treatment that may lead to severely impaired cell-mediated immunity.
      2. High mortality rate associated with MDR-TB in this group.  Among patients with active MDR-TB, the case-fatality rate was extraordinarily high (72 to 89 percent).  Of eight HCWs from these hospitals who developed active MDR-TB, four with known HIV infection died.
      3. The voluntary reassignment program for immunocompromised HCWs.  Immunocompromised HCWS shall be referred to an employee health professional who can counsel the employee on an individual basis regarding his/her risk of TB.  Upon the request of the immunocompromised HCW, the facility shall offer, but not compel, a work setting in which the HCW would have the lowest possible risk of occupational exposure TB.  Information provided by HCWs regarding their immune status shall be treated confidentially.
    9. Decontamination.
      1. Environmental Surfaces.

        The same routine daily cleaning procedures used in other rooms in the facility shall be used to clean rooms of patients who are on AFB isolation.  Personnel cleaning the room should follow AFB isolation practices.

      2. Equipment Used On Patients.

        Equipment used on patients with TB is unlikely to be involved in the transmission of-the organism, although transmission by contaminated bronchoscopes has been demonstrated.  The policies and procedures developed by the infection control program for cleaning, disinfecting, or sterilizing patient-care equipment should be followed.

    10. Coordination of Efforts With Public Health Department.

      Results of all AFB positive sputum smears, cultures positive for TB, and drug-susceptibility results on TB isolates shall be forwarded to the _____________ [list the name of the health department to be notified] health department as soon as they become available, in accordance with State and local laws and regulations.

      ___________ [list the person/position responsible for follow up activities] shall coordinate efforts with State, tribal and local health departments to perform appropriate contact investigations on patients and HCWs with active TB.  A discharge plan coordinated with the patient or HCW, the health department, and the inpatient facility shall be implemented.

    11. Specific Settings or Circumstances.
      1. Operating Rooms.

        Elective operative procedures on patients with TB will be delayed until the patient is no longer infectious.  If procedures must be performed, they will be done in operating rooms with anterooms if possible.  The doors to the operating room shall be closed and traffic in and out of the room shall be kept to a minimum.  Attempts will be made to perform the procedure at a time when other patients are not present in the operative suite and when a minimum number of personnel are present.

        The patient will be monitored during recovery in the specify the location of the room, e.g. ICU isolation room meeting TB isolation room ventilation recommendations.

      2. Autopsy rooms (Inpatient Only).

        Due to the probability of the presence of infectious aerosols, autopsy rooms shall be at negative pressure with respect to adjacent areas, with room air exhausted directly to the outside of the building.  There shall be no recirculation of air exhausted from autopsy rooms.  ASHRAE recommends that autopsy rooms have ventilation that provides 12 total air changes per hour.  Respiratory protection approved for TB exposure shall be worn by personnel while performing autopsies on patients were suspected of having TB.

      3. Emergency medical services.

        When emergency medical response personnel or others must transport patients with confirmed or suspected active TB, a surgical mask shall be placed on the patient, if possible.  The HCW shall wear a respirator approved for TB exposure in emergency transport situations and vehicles.

      4. Laboratories.

        Laboratories processing specimens for mycobacterial studies (e.g., AFB smears and cultures) shall conform to CDC criteria.

      5. Dental Offices.

        Patients with history and symptoms suggestive of active TB shall be promptly referred for evaluation for possible infectiousness.  If the patient is determined to have infectious TB, elective dental treatment should be deferred until the patient is no longer infectious.

        If dental procedures must be performed on a patient who has, or is strongly suspected of having infectious TB, AFB isolation practices shall be implemented.  Dental procedures shall be done in operatories properly designed for used of nitrous oxide analgesia, i.e. an enclosed room with a non-recirculating ventilation system.  These rooms should have at least 10 ACH in existing facilities and 12 ACH in new construction.  The doors to the operatories shall be closed and traffic in and out of the room shall be kept to a minimum.  Attempts will be made to perform the procedure at a time when other patients are not present in the operative suite and when a minimum number of personnel are present.  The patient will be monitored during recovery in an individual room meeting AFB isolation room ventilation recommendations.  Dental HCWs shall use respiratory protection approved for TB exposure while performing procedures on such patients .

      6. Home health services.

        Precautions may be necessary for HCWs visiting the home of patients with suspected or confirmed infectious TB.  The precautions include instructing the patient to cover his/her mouth and nose with a tissue when coughing or sneezing, offering the patient a surgical mask, and HCWs wearing respiratory protection approved for TB exposure during high risk procedures such as entering the patient's room.  Cough inducing procedures will not be performed on patients with infectious TB in the home.  Home health care personnel will assist in preventing TB transmission by educating the patient about the importance of taking medications as prescribed and by administering directly observed therapy.

  7. REFERENCES.

    "The IHS Standards of Care for Tuberculosis:  INH preventive therapy." The IHS Primary Care Provider 1989; 14:54-58.

    "Treatment of Tuberculosis and Tuberculous Infection in Adults and Children" Am J Respir Crit Care Med 149:1359-1374 1994.

    "Screening for Tuberculosis and Tuberculous Infection in High-Risk Populations and The Use of Preventive Therapy for Tuberculous Infection in the U.S." MMWR 39: Supplement No. RR-8, May 18, 1990.

    "Diagnostic Standards and Classification of Tuberculosis." Amer Rev Respir Dis 142:725-735, 1990.

    "Prevention and Control of Tuberculosis in Facilities Providing Long Term Care to the Elderly."  MMWR 39: Supplement No. RR-10, July 13, 1990.

    "Enforcement Policy and Procedures for Occupational Exposure to Tuberculosis."  U.S. Department of Labor (OSHA) Memorandum, October 8, 1993.

    "Guidelines for Preventing the Transmission of Tuberculosis in Health-Care Facilities, 1994."  Centers for Disease Control and Prevention:  MMWR 43: RR-13, October 28, 1994.

    "Control of Tuberculosis in the United States."  Amer Rev Respir Dis 146:1623-1633, 1992.

    "Health Facilities Planning Manual."  US Public Health Service, Indian Health Service, Rockville, MD.


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