Risk Assessment Reduce the workers and Biosafety is an inexact - PDF document

Risk Analysis Biosafety Risk assessment, Risk � Risk analysis encom passes Management & risk risk assessm ent, risk communication m anagem ent, and risk com m unication. Ephy Khaemba International Livestock Research Institute Utilizing the Risk Assessment What is Risk Assessment? as a Deciding Factor “ The biosafety level assigned for � � Risk: the probability that harm, injury, or the specific work to be done is disease will occur; the probability of an therefore driven by professional adverse (health) effect judgment based on a risk assessment” - WHO Laboratory � Assessment : The process of gathering Biosafety Manual and judging evidence in order to decide whether a person has achieved a standard or objective Risk Assessment Risk Assessment � Reduce the worker’s and � “Biosafety is an inexact science, and environment’s risk of exposure the interacting system of agents and activities and the people performing them are constantly changing.” � The Risk is never zero • Every etiologic agent is different • Every laboratory is different • Every person is different � Biological Safety:Principles and Practices, 4th Ed. Fleming DO, Hunt DL, eds., p. 81. Washington, DC. American Society for Microbiology, 2006 1

RI SK MANAGEMENT Laboratory Hazards PROCESS Biological organisms Make Risk Decision & Develop � Controls Access Hazards Animals � Chemicals � Radiation � I dentify Hazards I mplement Controls Physical � Supervise and Evaluate Risk Management steps Risk Assessment steps Ways to mitigate RISK What hazard? � Anticipate the issues Biohazard: a biological agent or condition that constitutes a hazard to man or his � Remove or reduce the hazard environment; also a hazard posed by such an agent or condition. � I ncrease familiarity with the hazard � Train to deal with hazard From Webster’s 9th New Collegiate Dictionary, Miriam- Webster Inc. Publishers, Springfield, MA � I ncrease protection from the hazard USA, 1985 � Have a back up plan (in case all of the previous fail) The CDC/ NI H BMBL and the WHO Laboratory Biosafety Manual Qualitative Risk Assessment Outcome-oriented, not prescriptive, but ultimately based on risk Identify all applicable risk factors assessment - Biological agent Laboratory director responsible for assessing risks and setting - Work procedures and practices the biosafety level - Personnel A participatory strategy works best - Facility involve workers, safety professionals • Review guidelines, regulations, publications develop training initiatives • Assess available epidemiological and field data vigilant review for effectiveness Consult subject matter experts • Recognize any available animal data 2

Over-arching Principles Biohazard Risk Assessment • Standard precautions are always advisable A biohazard risk assessment is a process which evaluates the risk posed by the • Be conservative when insufficient information forces subjective judgment agent, the procedure (s), and the worker to: • Everyone is responsible for the risk assessment • work and management process – not just the • staff “management” • environment • community Step 1 Risk Assessment FIVE STEP approach to Risk Assessment: Identify agent hazards 1. Identify laboratory procedure hazards 2. Determine preliminary Biosafety Level 3. � 4. Evaluate staff for proficiency in laboratory and occupational health needs and use of safety equipment. Identify Agent � 5. Review the risk assessment with a Biosafety professional, subject matter expert and the Institutional Biosafety Committee. Risk Assessment: Agent Basis Biological Hazard Recognition ► What is known about the agent (Category, Biological organism Amount of agent, Transmissibility)? Pathogenicity ► What information is in the literature? Mode of transmission Work practices ► Is an LD 50 , ID 50 or TCID 50 given? Animal work ► Is the agent/material known to cause Training infectious or toxigenic disease? Personnel Workplace surveys Publications/research 3

Agent Based Risk Assessment Agent Based Risk Assessment ► Ordinary work procedures and type of � Potential outcome of exposure work to be done (clinical samples, research, large scale, concentration) � Natural route of infection/other routes of ► Is the host range limited or broad? infection (parenteral, airborne, ingestion) ► Is post-exposure treatment, vaccine or � Stability in the environment prophylaxis available? Agent Based Risk Assessment Agent Based Risk Assessment � Information available (animal studies, � Ordinary work procedures and type of work to be done (clinical samples, laboratory-acquired infections, clinical research, large scale, concentration) reports � Worker (host) factors (training, health) � Laboratory activity (sonication, aerosolization, centrifugation, etc.) � Other agent related questions? � Genetic manipulation Risk Assessment: Lab Activity Step 2 Basis � Conduct a protocol based biohazard risk assessment � I nclude laboratory activities that may not be listed in protocols � Evaluate Lab Activities to Identify Potential Hazard 4

Risk Assessment for the Potential routes of transmission Clinical Lab for LAIs: What: Investigate potential routes of transmission Assessment of risk • Spills/ Splashes for Laboratory Acquired Infections focuses Aerosol • primarily on How? Identify activities which could release the exposures the prevention of organism and expose the worker, co-workers Cuts/ Lacerations • and/or the environment laboratory- Needle sticks acquired • Animal bites infections (LAI ) • Factors Necessary for CHAI N OF I NFECTI ON Transmission proper training, use proper PPE Pathogen/ I mproper practices, training or equipment allows organism to escape from vial Infectious organism � Presence of agent x T RAI NI NG A P P R O P R I A T E R I S K A S S E S S M E N T & P R O P E R resistance in environment, improper disinfection Exposure/ � Stability of agent effective disinfection, proper ventilation, PPE, reduce Incident aerosols x � Sufficient virulence of agent Route of transmission route of entry provided: scratch, blood, ingestion, mucous membrane, or respiratory exposure � Mechanism of transmission to host x Infectious dose vaccination � Correct portal of entry x Host available treatment � Susceptible host Susceptibility Compromised immune status x surveillance INFECTION Agent Considerations Aerosol Issues AEROSOL I NFECTI OUS DOSE* • Procedures that impart energy into a Agent Estimated I nfectious Dose � � microbial suspension are a potential source of Ebola virus 1 – – aerosol (Chatigny, 1974) M. tb 1 – 10 – – Tularemia 10 – – Brucella 10 – 100 – – • Laboratory procedures having potential of Anthrax 2,500-55,000 viable spores – – releasing aerosols are ubiquitous Cholera 10^ 8 – – � opening vials, centrifugation, mixing, sonication, Salmonella typhi 10^ 3 – – blending, grinding, shaking, vortexing, spills, pipetting, E. coli 10^ 8 – – etc. E. coli O157:H7 10 – 100 – – Shigella spp. 10 – 100 – – 5

Viable Particles Recovered from Microbiological procedures Air presenting risk of aerosol in lab Procedure # Particles/ft3 of air • streaking plates 6 • spreading material on slides sonic oscillator � � cooling loop in media mixing w/ pipette 7 • � � “sniffing plates” • � overflow from mixer � 9 Catalase tests • � opening lyophilized vial 135 � Pipetting • top removed after blending � 1500 � Inoculating blood tubes • dropping flask of culture � 1551 � • heating loop in bunsen burner flame dropping lyophilized culture � 4839 � Rapid test kits/automated liquid dispensing • (from Chatigny 1974 Pipetting Sharps Hazards Syringes and needles, scalpels and broken glass Auto-inoculation � mishandling � separation from syringe � no mouth pipetting � Inoculating blood tubes and bottles � disposable plastic pipettes � � inappropriate disposal don’t expel last drop � � poor work practices all samples handled in biosafety cabinet � � collect pipettes inside biosafety cabinet Laboratory Considerations Sharps Precautions � Facility Specific locations for sharps in lab � Never fill sharps containers all the way � � Laboratory work practices Use self-retracting needles and other � engineering controls � PPE no recapping, bending, breaking, etc. � � Resources Substitute plastic for glass when possible � Avoid glass Pasteur pipettes and capillary � Procedures � tubes � culture Practice “infectious spill with glass” clean-up � procedures � large volumes immediate collection/disposal � � animals � diagnostics 6

Risk Assessment No Problem Here… Right? Considerations • Pathogen (Agent) • Procedures (Protocol) • Protective Equipment • Place (lab facility) • Personnel (host) � the 5 P’s of Risk Assessment) Step 3 Establishing a “Starting Point” Determining the 1. preliminary biosafety level 2. additional precautions � Preliminary Determination of Biosafety Requires a comprehensive understanding of Level the practices, safety equipment, and laboratory facility safeguards involved in the work to be undertaken Step 4 Worker Assessment � Worker assessment must focus on identifying gaps: 1) Worker experience 2) Occupational health and safety (includes prophylaxis and fit � Worker Assessment testing ) 7