general concepts on tb infection control

1. General concepts on TB infection control

2. There are several reason for nocomial transmission increase in industrialised countries Over the last decades there has been a r5eassurgance of the disease in Europe and USA. Over period 1985 1992. There are several reason for nocomial transmission increase in industrialised countries Over the last decades there has been a r5eassurgance of the disease in Europe and USA. Over period 1985 1992.

3. The purpose of infection control Program To reduce the risk of Mycobacterium tuberculosis transmission to health care workers, patients, and others in the health care facility

4. Mycobacterium tuberculosis Generated by coughing, sneezing, speaking Remains airborne and spreading air currents Aerobic, desiccation-resistant 1-100 organisms may infect Droplet nuclei, 1-5 Most exposed persons do not become infected Prevalence of TB in the community Type of health care facility (TB clinic, HIV clinics) Patients population served (chronics, MDR-TB, Infectious TB before dg) The area in the health care facility HCW job category (patient isolation rooms, rooms for dg. procedures that stimulates coughing, and Tx rooms, surgery open abscess irrigation, autopsies) Effectiveness of infection control interventions Patient Factors �Infectiousness, understanding of cough hygiene, treatment = Number of infectious bacilli in room air Transmission affected by Infectiousness of patient Environmental conditions Duration of exposure Because droplet nuclei are so small, TB remains airborne and spreads easily in air currents.The organism is aerobic and desiccation-resistant. This means it needs air to survive and does not dry out very quickly. As previously stated, droplet nuclei may range in size from 1-5 ?m (micro meters) in diameter. Prevalence of TB in the community Type of health care facility (TB clinic, HIV clinics) Patients population served (chronics, MDR-TB, Infectious TB before dg) The area in the health care facility HCW job category (patient isolation rooms, rooms for dg. procedures that stimulates coughing, and Tx rooms, surgery open abscess irrigation, autopsies) Effectiveness of infection control interventions Patient Factors �Infectiousness, understanding of cough hygiene, treatment = Number of infectious bacilli in room air Transmission affected by Infectiousness of patient Environmental conditions Duration of exposure Because droplet nuclei are so small, TB remains airborne and spreads easily in air currents.The organism is aerobic and desiccation-resistant. This means it needs air to survive and does not dry out very quickly. As previously stated, droplet nuclei may range in size from 1-5 ?m (micro meters) in diameter.

5. Violent sneeze Infectious droplet nuclei Primary source of infection Critical diameter 1-5�m Characteristics of infectious source SM+ most infectious >5 000 bacilli/ml sputum in SM+ cases 20% of transmission by SM- cases Air circulation and ventilation We will start with the patient since they are typically the source of infection. This slide shows a violent sneeze caught on film by high speed photography showing large liquid droplets. Most of these large, visible droplets will fall to the ground. However, the small droplet nuclei that can reach the deep lung are not visible and are 1:5 micro meters in size.Infectious droplet nuclei Primary source of infection Critical diameter 1-5�m Characteristics of infectious source SM+ most infectious >5 000 bacilli/ml sputum in SM+ cases 20% of transmission by SM- cases Air circulation and ventilation We will start with the patient since they are typically the source of infection. This slide shows a violent sneeze caught on film by high speed photography showing large liquid droplets. Most of these large, visible droplets will fall to the ground. However, the small droplet nuclei that can reach the deep lung are not visible and are 1:5 micro meters in size.

6. Reasons for the increase in nosocomial TB transmission in industrialised countries Resurgence of TB Poor hospital infection control practices Multidrug resistant TB HIV infection There are several reason for nocomial transmission increase in industrialised countries Over the last decades there has been a r5eassurgance of the disease in Europe and USA. Over period 1985 1992. Infection control were relaxed or simply not followed because of perception that TB was not longer important. The advent of MDR-TB encouraged its spread in the hospitals not because these patients are more infectious but because first line drugs are not adequate for its treatment and patients remain longer infectiousThere are several reason for nocomial transmission increase in industrialised countries Over the last decades there has been a r5eassurgance of the disease in Europe and USA. Over period 1985 1992. Infection control were relaxed or simply not followed because of perception that TB was not longer important. The advent of MDR-TB encouraged its spread in the hospitals not because these patients are more infectious but because first line drugs are not adequate for its treatment and patients remain longer infectious

7. The ��at risk �� health care worker Nurses Physicians, specialists in internal medicine specialists in respiratory medicine (extra risk providing bronchoscopy, caring ventilated patients in ICU) Pathologists Laboratory staff

8. Fundamentals of Infection Control (1)Hierarchy of Infection Control Administrative controls to reduce risk of exposure, infection, and disease through policy and practice Engineering controls to reduce concentration of TB infectious droplet nuclei in areas where contamination of air is likely Personal respiratory protection to protect personnel who work in areas where is still risk of exposure to MTB, e. g., isolation rooms, aerosol-generating procedures are performed. As Paul has explained, we use the hierarchy to prevent the transmission of TB. More specifically, we use: Administrative controls to reduce risk of exposure, infection, and disease through policy and practice. We use Engineering controls to reduce concentration of infectious bacilli in air in areas where contamination of air is likely. And we use Personal respiratory protection to protect personnel who must work in environments with contaminated air. In the next 2 lectures we will discuss administrative controls. This afternoon we will discuss personal respiratory protection and start the respirator fit testing for all of you. Tomorrow we will complete the hierarchy of infection controls by discussing engineering controls. Administrative controls: reduce risk of exposure via effective IC program Environmental controls: prevent spread and reduce concentration of droplet nuclei Respiratory protection controls: further reduce risk of exposure in special areas and circumstances Administrative controls to reduce risk of exposure, infection, and disease through policy and practice Engineering controls to reduce concentration of TB infectious droplet nuclei in areas where contamination of air is likely Personal respiratory protection to protect personnel who work in areas where is still risk of exposure to MTB, e. g., isolation rooms, aerosol-generating procedures are performed. As Paul has explained, we use the hierarchy to prevent the transmission of TB. More specifically, we use: Administrative controls to reduce risk of exposure, infection, and disease through policy and practice. We use Engineering controls to reduce concentration of infectious bacilli in air in areas where contamination of air is likely. And we use Personal respiratory protection to protect personnel who must work in environments with contaminated air. In the next 2 lectures we will discuss administrative controls. This afternoon we will discuss personal respiratory protection and start the respirator fit testing for all of you. Tomorrow we will complete the hierarchy of infection controls by discussing engineering controls. Administrative controls: reduce risk of exposure via effective IC program Environmental controls: prevent spread and reduce concentration of droplet nuclei Respiratory protection controls: further reduce risk of exposure in special areas and circumstances

9. Administrative control measures Administrative Controls Prevention of droplet nuclei containing M. tuberculosis from being generated; Prevention of TB exposure to staff and patients; and Implementation of rapid and recommended diagnostic investigation and appropriate treatment for patients and staff suspected or known to have TB. Administrative controls are managerial measures to significantly reduce the risk of TB transmission by preventing the generation of droplet nuclei. They also include procedures for implementing, monitoring, enforcing, evaluating, and revising infection control programs on a routineAdministrative controls are managerial measures to significantly reduce the risk of TB transmission by preventing the generation of droplet nuclei. They also include procedures for implementing, monitoring, enforcing, evaluating, and revising infection control programs on a routine

10. Administrative control measures Administrative Controls (1) Assign responsibility for TB infection control (IC) Conduct TB risk assessment and develop written TB IC plan, including AII precautions Ensure timely lab processing and reporting Implement effective work practices for managing TB patients

11. Administrative control measures Administrative Controls (2) Test and evaluate HCWs at risk for TB or for exposure to M. tuberculosis Train HCWs about TB infection control Ensure proper cleaning of equipment Use appropriate signage advising cough etiquette and respiratory hygiene

12. Administrative control measures Assignment of responsibilities Supervisory responsibility should be delegated to a specific person or infection control team with a leader Should include experts in: - infection control - hospital epidemiology - clinician - engineering IC team responsible for all aspects of the IC program

13. Administrative control measures TB Risk Classifications (1) All settings should perform risk classification as part of risk assessment to determine need for and frequency of an HCW testing program, regardless of likelihood of encountering persons with TB disease.

14. Administrative control measures TB Risk Classifications (2) Low risk � Persons with TB disease not expected to be encountered; exposure unlikely Medium risk � HCWs will or might be exposed to persons with TB disease Potential ongoing transmission � Temporary classification for any settings with evidence of person-to-person transmission of M. tuberculosis

15. Administrative control measures TB Risk Classifications (3) High risk Wards (thoracic surgery, pediatric, extrapulmonary, non TB pulmonary department) Intensive care ward Surgery Consultation ward Medium risk Clinical laboratory Drugstore Administration Maintenance personnel High risk Wards (thoracic surgery, pediatric, extrapulmonary, non TB pulmonary department) Intensive care ward Surgery Consultation ward Medium risk Clinical laboratory Drugstore Administration Maintenance personnel

16. Administrative control measuresTB Risk Classifications (4)

17. Administrative control measures TB Risk Classifications (5)

18. Administrative control measures Implement effective work practices for managing TB patients Infection control plan (including TB) specific to each area within facility, and HCW group based on level of risk Put all procedures in writing plan including: Early detection isolation and treatment of infectious TB patients Patient education Decreasing of cough induction procedures Administrative support for procedures in the plan, including quality assurance; Educate staff about the plan - organization, rationale, and what is expected of them TB screening program for health care workers Education of patients and increasing community awareness; and Coordination and communication between the TB and HIV programs. Specify who has responsibility and authority Specify procedures for risk assessment Write out policies for: Triage and evaluation of TB suspect cases at entry to prison and during imprisonment Separation, isolation and transfer patient within the prison system Hospitalization, transfer procedures Monitoring infectiousness (frequency) Special precautions for high risk procedures and locations Engineering IC and its monitoring Personal respiratory protection Program Training and education for personnel Specify responsibilities Supervisory responsibility delegate to a specific person or infection control team with a leader including experts in: - infection control, hospital epidemiology, clinics, engineering Written policies for: - flow of infectious patients, patients hospitalization, transfer and discharge - monitoring of infectiousness - special precautions for high risk procedures and locations - monitoring of engineering controls - personal respiratory protection program - staff education Screening and management of health care workers Ongoing monitoring of the program Annual evaluation of the program Identify each factor that contributes to transmission of TB and MDR TB in institutions Risk assessment Develop written plan that addresses these factors at each possible point of intervention practical, affordable, comprehensive, creative Put the IC plan into practice Monitor and enforce infection control policies Evaluate and revise accordingly Specify who has responsibility and authority Specify procedures for risk assessment Write out policies for: Triage and evaluation of TB suspect cases at entry to prison and during imprisonment Separation, isolation and transfer patient within the prison system Hospitalization, transfer procedures Monitoring infectiousness (frequency) Special precautions for high risk procedures and locations Engineering IC and its monitoring Personal respiratory protection Program Training and education for personnel Specify responsibilities Supervisory responsibility delegate to a specific person or infection control team with a leader including experts in: - infection control, hospital epidemiology, clinics, engineering Written policies for: - flow of infectious patients, patients hospitalization, transfer and discharge - monitoring of infectiousness - special precautions for high risk procedures and locations - monitoring of engineering controls - personal respiratory protection program - staff education Screening and management of health care workers Ongoing monitoring of the program Annual evaluation of the program Identify each factor that contributes to transmission of TB and MDR TB in institutions Risk assessment Develop written plan that addresses these factors at each possible point of intervention practical, affordable, comprehensive, creative Put the IC plan into practice Monitor and enforce infection control policies Evaluate and revise accordingly

19. Administrative control measures Ensure early identification, diagnostic evaluation, isolation and treatment (2) High index of suspicious for TB TB risk groups (contacts, HIV, medical history, social, epidemiological factors) Diagnostic methods used for TB/MDR-TB Isolation protocols and procedures Adequate treatment Written protocols to ensure early identification, diagnostic evaluation, isolation and treatment Isolation and discontinuation of isolation protocols and procedures Flow of infectious patients, in hospital, transfer and discharge Special precautions for high risk procedures and locations Use and maintain environmental control measures Personal respiratory protection program HCW and clients education Written protocols to ensure early identification, diagnostic evaluation, isolation and treatment Isolation and discontinuation of isolation protocols and procedures Flow of infectious patients, in hospital, transfer and discharge Special precautions for high risk procedures and locations Use and maintain environmental control measures Personal respiratory protection program HCW and clients education

20. Administrative control measures Isolation procedures Designated high-risk areas (isolation rooms) for TB and MDR-TB patients or suspects Roles and regulations of isolations Patient education, signed informed consent Isolation: AFB+ new TB case or strongly suspected for TB Patient with TB again become smear positive Determine infectiousness and drug resistance as soon as possible sputum smear, culture and susceptibility testing, chest X-ray Monitor infectiousness (frequency) Interrupt isolation Major contents of written IC plan will:Specify who has responsibility and authority Specify the procedures for the risk assessment Include written policies for the: Triage and evaluation of suspected cases Transfer into and out of designated high-risk areas for TB and MDR TB patients or suspects Monitoring infectiousness (frequency) Note to speaker: Why are suspects important in the IC plan? They may be transmitters of TB and we want to prevent transmission to others. If they don�t have TB, we don�t want them to become infected while their diagnosis is being performed.Major contents of written IC plan will:Specify who has responsibility and authority Specify the procedures for the risk assessment Include written policies for the: Triage and evaluation of suspected cases Transfer into and out of designated high-risk areas for TB and MDR TB patients or suspects Monitoring infectiousness (frequency) Note to speaker: Why are suspects important in the IC plan? They may be transmitters of TB and we want to prevent transmission to others. If they don�t have TB, we don�t want them to become infected while their diagnosis is being performed.

21. Environmental Controls Second defense in TB IC program, after administrative controls, Control source of infection Dilute and remove contaminated air Control airflow (clean air to less-clean air)

22. UV lamps

23. Local Exhaust Ventilation (1) Source-control method for capturing airborne contaminants Enclosing device: source fully or partially enclosed; include tents, booths, and biologic safety cabinets (BSCs) External device: source near but outside enclosure Should remove at least 99% of particles before next patient or HCW enters Use for cough-inducing and aerosol-producing procedures Laminar boxes Booth for sputum induction Isolation rooms with negative pressure

24. General Ventilation (2) Systems that dilute and remove contaminated air and control airflow patterns in a room Single-pass system preferred for AII rooms Maintain AII rooms under negative pressure Existing settings: =6 air changes/hr (ACH) New or renovated settings: =12 ACH Recirculation (HEPA filtration, UV irradiation) Engineers must look after function of ventilation system, to determine airflow and air exchange per hour

25. Ventilation (2)Airflow

26. Air flow measurements

27. Natural ventilation

28. Air-Cleaning MethodsHEPA filters Use as supplement to ventilation Used to filter infectious droplet nuclei from the air Must be used When discharging air from local exhaust ventilation booths directly into surrounding room When discharging air from an AII room into the general ventilation system Can be used to clean air that is exhausted to outside

29. HEPA Filter

30. Air-Cleaning MethodsUVGI Kills or inactivates M. tuberculosis Use as supplement to ventilation Not substitute for negative pressure rooms Not substitute for HEPA filtration when air recirculated from AII room into other areas Emphasis on safety and maintenance Occupational exposure limits Overexposure can cause damage to skin, eyes UVGI systems must be properly installed and maintained

31. UV light kills TM in 5 minutes Types - opened - closed Side effects - erythema - photokeratitis Maximal UV irradiance which is not dangerous for HCW 0,2 mcW/cm2 or 6.000 mcJ/cm2 , exposure time 8 hours Minimum UV irradiation 1Watt/1m2 UV light kills TM in 5 minutes Types - opened - closed Side effects - erythema - photokeratitis Maximal UV irradiance which is not dangerous for HCW 0,2 mcW/cm2 or 6.000 mcJ/cm2 , exposure time 8 hours Minimum UV irradiation 1Watt/1m2

32. UVGI irradiation in upper parts air of facility

35. Respiratory ProtectionGeneral Third level in the IC hierarchy Should be used by persons Entering rooms of suspected/confirmed TB patients Around cough- or aerosol-producing procedures In settings where administrative and environmental controls will not prevent the inhalation of infectious droplet nuclei Decision on use of respiratory protection (RP) in labs should be made on case-by-case basis Settings with no AII rooms, no cough- or aerosol-producing procedures, or no expectations of patients with suspected or confirmed TB do not need an RP program Have written protocols for recognizing signs or symptoms of TB and referring or transferring patients to a setting where they can be managed Settings with no AII rooms, no cough- or aerosol-producing procedures, or no expectations of patients with suspected or confirmed TB do not need an RP program Have written protocols for recognizing signs or symptoms of TB and referring or transferring patients to a setting where they can be managed

36. Respiratory Protection (RP) Controls Implement RP program Train HCWs in RP Train patients in respiratory hygiene Settings where HCWs use RP to prevent M. tuberculosis infection should develop, implement, and maintain an RP program; include all HCWs who use RP Provide HCWs annual training on TB control, IC, and RP Give HCWs time to become proficient and comfortable with respirators Settings where HCWs use RP to prevent M. tuberculosis infection should develop, implement, and maintain an RP program; include all HCWs who use RP Provide HCWs annual training on TB control, IC, and RP Give HCWs time to become proficient and comfortable with respirators

37. Nine NIOSH filter types 3 levels of filter efficiency: 95% (called �95�) 99% (called �99�) 99.97% (called �100�) 3 categories of resistance to filter efficiency degradation: N (NOT resistant to oil) R (Resistant to oil) P (Oil proof)

38. Central Europe National standards CEN standards (Initial filter penetration) NaCl < 20% = P1 < 6% = P2 < 3% = P3 Paraffin oil NA = P1 < 2% = P2 < 1% = P3 Considerations for electing Respirators (1) Minimum respiratory protection is a filtering facepiece respirator (nonpowered, air-purifying, half-facepiece, such as N95 disposable). In high-risk situations (cough- or aerosol-producing activities), additional protection may be needed Use respirators that also protect HCWs against mucous membrane exposure to bloodborne pathogens as appropriate Use respirators without exhalation valve during procedures requiring sterile field Consider offering respirators (e.g., N95 disposable) to visitors to AII rooms In certain settings (e.g., AII rooms, vehicles carrying infectious patients), administrative and environmental controls may not be enough to protect HCWs Respirator usage regulated by OSHA�s general industry standard Considerations for electing Respirators (1) Minimum respiratory protection is a filtering facepiece respirator (nonpowered, air-purifying, half-facepiece, such as N95 disposable). In high-risk situations (cough- or aerosol-producing activities), additional protection may be needed Use respirators that also protect HCWs against mucous membrane exposure to bloodborne pathogens as appropriate Use respirators without exhalation valve during procedures requiring sterile field Consider offering respirators (e.g., N95 disposable) to visitors to AII rooms In certain settings (e.g., AII rooms, vehicles carrying infectious patients), administrative and environmental controls may not be enough to protect HCWs Respirator usage regulated by OSHA�s general industry standard

39. Personal protective equipment Personal protective equipment Masks (patients) Respirators (HCWs) Personal protective equipment Masks (patients) Respirators (HCWs)

40. Respirator program elements Selection Medical evaluation Fit testing Use Maintenance and care Training Program evaluation

41. Strategy for preventing institutional transmission of TB and MDR TB (1) Identify each factor that contributes to transmission of TB and MDR TB in institutions Develop written plan that addresses these factors at each possible point of intervention practical, affordable, comprehensive, creative Put the IC plan into practice Monitor and enforce infection control policies Evaluate and revise accordingly In developing a strategy for preventing institutional transmission of TB and MDR TB, it is critical to: Identify each factor that contributes to transmission of TB and MDR TB in institutions. Develop a written plan that addresses these factors at each possible point of intervention. Ensure that the plan is practical, affordable, and comprehensive. In some cases, creative solutions are required and you may have to consider something that has not been tried yet. In developing a strategy for preventing institutional transmission of TB and MDR TB, it is critical to: Identify each factor that contributes to transmission of TB and MDR TB in institutions. Develop a written plan that addresses these factors at each possible point of intervention. Ensure that the plan is practical, affordable, and comprehensive. In some cases, creative solutions are required and you may have to consider something that has not been tried yet.

42. Strategy for preventing institutional transmission of TB and MDR TB (2) LIFECYCLE OF IC PLAN Develop Implement Evaluate Revise

43. Human recourses for IC Humans are social by nature and particularly adept at utilizing systems of communication for self-expression, the exchange of ideas, and organization. Human resources- the different kinds of clinical and non clinical staff who make each public health intervention happen. The performance of health care systems depends on the knowledge, skills and motivation of the people responsible for delivering services* *The World Health Organization Report 2000

44. Periodic screening of health workers to detect disease at an early stage Each year for employees Medical questionnaire Chest x-ray, Mantoux test Sputum exam if cough > 3 weeks Special consideration for employees with increased individual risk Periodic screening of health workers and prisoners should be conducted to detect disease at an early stage. This screening should be conducted each year for employees and twice yearly for prisoners. Health workers can be screened by a medical questionnaire as well as a chest radiograph if findings are suggestive of previous TB, or a sputum exam if cough > 3 weeks. Finally, special consideration should be given to employees or prisoners with increased individual risk. Periodic screening of health workers and prisoners should be conducted to detect disease at an early stage. This screening should be conducted each year for employees and twice yearly for prisoners. Health workers can be screened by a medical questionnaire as well as a chest radiograph if findings are suggestive of previous TB, or a sputum exam if cough > 3 weeks. Finally, special consideration should be given to employees or prisoners with increased individual risk.

45. Thank you