TB Laboratory Safety: Practices and Principles-An International Perspective

1. TB Laboratory Safety: Practices and Principles-An International Perspective

2. Pathogenesis of Tuberculosis Globally, millions of people have tuberculosis (TB) Transmission by aerosols Agent - Mycobacterium tuberculosis (M.tb) Infection vs. disease Infection may be latent or progress to disease Primarily affects lungs but may infect other organs

3. M.tuberculosis - acid-fast rod shaped bacterium - resist decolorization w acid alcohol - mycolic acid and waxes in cell wall - does not release stain primary stain

5. Pathogensis - ability of organism to cause disease - route of transmission - stability of organism - infectious dose - concentration of organisms per volume - origin of agent - condition of host

6. Mycobacterium tuberculosis �is spread through the air from person to person via coughing, sneezing, and even singing and speaking. � Tiny invisible droplets dry quickly to form droplet nuclei that are less than 5 microns in diameter. They can contain disease organisms such as tubercle bacilli. These droplets may remain suspended in the atmosphere for several hours. Another person can breathe in the particles and become infected. This is especially dangerous in a confined area. Keep in mind, when appropriate techniques are employed, there is very little risk of acquiring infection in the laboratory. �Administrative controls should limit exposure. It is vital that all personnel be aware of potential hazards and work in a careful manner. Mycobacterium tuberculosis �is spread through the air from person to person via coughing, sneezing, and even singing and speaking. � Tiny invisible droplets dry quickly to form droplet nuclei that are less than 5 microns in diameter. They can contain disease organisms such as tubercle bacilli. These droplets may remain suspended in the atmosphere for several hours. Another person can breathe in the particles and become infected. This is especially dangerous in a confined area. Keep in mind, when appropriate techniques are employed, there is very little risk of acquiring infection in the laboratory. �Administrative controls should limit exposure. It is vital that all personnel be aware of potential hazards and work in a careful manner.

10. Direct Smear Microscopy -primary method for diagnosis of TB -perform without personal respiratory protection -No documented transmission on open bench -increased risks when HCWs have contact with coughing patients -administrative controls should limit this exposure

11. Specimen Collection Two kinds of containers are recommended for sputum collection:Specimen Collection Two kinds of containers are recommended for sputum collection:

12. The first is a disposable wide-mouthed, screw-capped container. It is made of unbreakable transparent plastic. It must be hermetically sealed to keep the specimen from leaking and drying out. � The second is a screw capped �Universal container� made of heavy glass which can be first sterilized, cleaned and used again. Many countries use their own containers. The first is a disposable wide-mouthed, screw-capped container. It is made of unbreakable transparent plastic. It must be hermetically sealed to keep the specimen from leaking and drying out. � The second is a screw capped �Universal container� made of heavy glass which can be first sterilized, cleaned and used again. Many countries use their own containers.

13. The greatest risk of infection in the laboratory involves sputum collection. Preparing smears presents less risk to the lab worker than exposure to direct coughing. � Since TB patients are sometimes directed to the lab for sputum collection, precautions must be taken to minimize the risk of exposure of laboratory staff and others. � Never collect sputum specimens inside the clinic or laboratory. The greatest risk of infection in the laboratory involves sputum collection. Preparing smears presents less risk to the lab worker than exposure to direct coughing. � Since TB patients are sometimes directed to the lab for sputum collection, precautions must be taken to minimize the risk of exposure of laboratory staff and others. � Never collect sputum specimens inside the clinic or laboratory.

14. It is safer to collect the specimens outside. � At all times, avoid creating aerosols in the lab! A daily routine that is followed exactly will help maintain safe conditions. � Strict adherence to safety regulations in the laboratory is crucial. Safe practices include: � �������� Washing hands frequently and always before and after performing any procedures. �������� Establishing airflow in working areas that will carry infectious particles away from lab personnel. This air should be exhausted into a remote location. �������� Strictly refraining from smoking and eating in the lab!!! �������� Wearing protective clothing and use of protective equipment. It is safer to collect the specimens outside. � At all times, avoid creating aerosols in the lab! A daily routine that is followed exactly will help maintain safe conditions. � Strict adherence to safety regulations in the laboratory is crucial. Safe practices include: � �������� Washing hands frequently and always before and after performing any procedures. �������� Establishing airflow in working areas that will carry infectious particles away from lab personnel. This air should be exhausted into a remote location. �������� Strictly refraining from smoking and eating in the lab!!! �������� Wearing protective clothing and use of protective equipment.

15. Laboratory Arrangement � To perform TB microscopy, a laboratory must have three areas: Laboratory Arrangement � To perform TB microscopy, a laboratory must have three areas:

16. Laboratory Arrangement for AFB Smear Microscopy Plan the lay out of laboratory room for an ease and safe work area Plan areas for each step and the movement of the sputum and work with AFB smears Movement of people in the work area must be minimized

17. Laboratory Arrangement

18. Transport of Specimen � Specimens should be packed and transported according to your country�s NTP guidelines. � Specimen Handling � Open the transport box carefully and examine it for cracked or broken containers. Discard any broken or leaking container and request another specimen. � All specimens must correspond with the accompanying list containing data of the TB suspect. � Once verified, record all information in the laboratory register.Transport of Specimen � Specimens should be packed and transported according to your country�s NTP guidelines. � Specimen Handling � Open the transport box carefully and examine it for cracked or broken containers. Discard any broken or leaking container and request another specimen. � All specimens must correspond with the accompanying list containing data of the TB suspect. � Once verified, record all information in the laboratory register.

19. Smear Preparation � To ensure a safe and consistent workflow, always arrange equipment and materials in the same way at the workbench.Smear Preparation � To ensure a safe and consistent workflow, always arrange equipment and materials in the same way at the workbench.

20. Surgical masks DO NOT protect against TB infection ! � Effective respiratory protection, such as an N95 respirator, is expensive, and probably unnecessary if the technician uses appropriate technique. � Careful handling during smear preparation should produce minimal aerosols. � The low risk of infections during these procedures may not justify the cost of respirators and gloves where there may be limited resources for TB control. � Each country must evaluate the risks and decide on the level of protection that is appropriate with the resources that may be available. In this training video, the technicians do not wear gloves or masks. Hand-washing and careful technique are acceptable practices for most countries. Remember, safety is everyone�s concern no matter what job is being performed.Surgical masks DO NOT protect against TB infection ! � Effective respiratory protection, such as an N95 respirator, is expensive, and probably unnecessary if the technician uses appropriate technique. � Careful handling during smear preparation should produce minimal aerosols. � The low risk of infections during these procedures may not justify the cost of respirators and gloves where there may be limited resources for TB control. � Each country must evaluate the risks and decide on the level of protection that is appropriate with the resources that may be available. In this training video, the technicians do not wear gloves or masks. Hand-washing and careful technique are acceptable practices for most countries. Remember, safety is everyone�s concern no matter what job is being performed.

21. Washing Hands � Always wash hands with soap and water after handling specimens and containers.Washing Hands � Always wash hands with soap and water after handling specimens and containers.

22. SAFE DISPOSAL OF WASTE MATERIALS Infectious waste can be divided in two types Disposable and re-usable materials Infectious TB lab waste is a risk to health care workers and the community Waste must be sterilized or disinfected before it leaves the laboratory Discard contaminated materials and sputum containers in 5% Phenol disinfectant

23. Disposable of Materials Incinerate: Use temperature not less than 100 0 degrees and dump in a hole or autoclave (if autoclaves is available)� Dump hole: Place waste in hole (about 1 m) and burn Cover hole with wood or a plate when half filled to prevent access by people, animals and birds

24. Re-usable Materials Place slide holders, forceps in a container with disinfectant Boil 20 min or more-or autoclave and wash for re-use

25. FLOW CHAR FOR DISPOSAL OF SPUTUM CONTAINERS

26.  FLOW CHART FOR DISPOSAL OF INFECTIOUS WASTE FROM TB LABORATORY

27. IMPORTANT POINTS TO REMEMBER:� Autoclaving is the safest and most satisfactory method of sterilization If autoclave is not available incinerate or burn the infectious waste Disinfect TB work surface areas with cotton wool soaked in 5% Phenol.

28. Risk Assessment

29. Risk Assessment Background information and ability to visualize potential outcomes Review laboratory records: -equipment maintenance -employee training -environmental monitoring -injury and surveillance reports Inspect the laboratory: -periodic walk-throughs -formal inspections by certifying agencies

30. Regular intervals, at least annually, more frequently if problems are discovered When a change occurs in the lab: -relocation or renovation -new employee(s) -new infectious agent or new reagent -new test or equipment Review published material, equipment manuals, manufacturers bulletins and newsletters, product inserts, scientific journals, published safety manuals and guidelinesReview published material, equipment manuals, manufacturers bulletins and newsletters, product inserts, scientific journals, published safety manuals and guidelines

31. Biosafety Cabinets (BSC) BSC - Class I -draws air into the cabinet and exhausts -protects environment from aerosols -produces negative pressure in the room -type of cabinet needed in most laboratories BSC - Class II -laminar flow and exhausts air -protects specimen and HCW -poor practices/maintenance increase hazard Monitor air flow daily for both types of cabinets

32. Biosafety Cabinets (BSC) Provide protection when used with appropriate lab practices Improper use and poor maintenance can be hazardous to the HCW and others in the work area -Bunsen burners disrupt air flow patterns -Contaminated hands/gloves endanger all lab staff Require daily monitoring and annual certification

34. Cultures, drug susceptibility and other tests -use ventilation in work areas -reduce the # of labs handling concentrated specimens -use biosafety cabinets to perform these procedures -well trained HCWs Safety with Suspensions of M.tb

37. flaming wet smears, centrifugation vortexing, pipetting, blending or sonicating specimensflaming wet smears, centrifugation vortexing, pipetting, blending or sonicating specimens

38. Safe TB Laboratory Practices Perform risk assessment Control ventilation and airflow patterns Prevent leaking specimen containers and contaminated work forms Frequent and appropriate hand washing

39. Safe Practices cont�d Prevent aerosols and spills Use of disinfectants and proper waste disposal No eating, drinking or smoking in the lab Have an emergency plan and supplies available

40. References 2000. TB Microscopy in Pacific Island countries Japan International Cooperation Agency and The research Institute of Tuberculosis Date of Publication. Acid-fast Direct Smear Microscopy,WHO, IUATLD, CDC, KNCV, JATA, APHL Draft publication. External Quality Assessment for AFB Microscopy 1995. Mycobacterium tuberculosis: assessing your laboratory. ASTPHL and CDC. 2002. Zambia AFB microscopy Training Manual. Central Board of Health. 1993, Channel BTE CO, Inc. About Tuberculosis, Booklet #37788. Southfield, MA. 1998. Laboratory Risk Assessment: What, Why and How. Centers for Disease Control and Prevention WHO. 1999. Guidelines for Prevention of Tuberculosis in Healthcare facilities in resource�limited settings