LABORATORY FACILITIES AND SAFETY

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LABORATORY FACILITIES AND SAFETY. Problem Scenario. - PowerPoint PPT Presentation

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  • LABORATORY FACILITIES AND SAFETY

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    Problem ScenarioYour laboratory is specialized in virology. There has been an important epidemic of H5N1 in your country and the Ministry of Health has asked you to be the referent laboratory for this pathology. What must you do to ensure biosafety in your laboratory?

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    The Quality System

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    Learning ObjectivesAt the end of this activity, you will be able to:Discuss the importance of laboratory designKnow what, where and when the risks areDiscuss the importance of using appropriate biosafety equipmentDescribe the four biosafety levelsOutline factors that need to be considered when assessing risk Keep appropriate biosafety documentation

  • 1. Importance of laboratory design

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    Laboratory design1-Path followed by the sample:Reception and registration of patientsSampling roomsDispatch between different laboratoriesAnalysis of samplesResultsDelivery and filing of resultsRelated services: Secretariat, Offices, Washery, Preparation and sterilization, Storage, Cold room.

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    PremisesReception : > reception and registration of patients > reception and registration of samples from other departments

    Sampling rooms > samples and sorting of samples

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    Blood clottingHaematologyBiochemistryWashroomReception and administrationBacteriologyGynaecological specimensBlood specimensCommon room, stairs to officesTOTAL AREA 104 M2

    ENTRANCEDisinfectionPlan

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    Washery with autoclaves for sterilization, wash and dry of glasswarePreparation, sterilization and distribution of culture media and reagents Stock roomCold roomCulture roomothers Service rooms

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    PremisesHigh ceilingWalls and ceiling with glossy paint : easy to clean and disinfect.Floor easy to clean and disinfect

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    Access to premisesOnly authorized persons: technicians, biologists, and maintenance staff ( badges)

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    Premises cleaningMaintenance on a daily basis:Benches Floor Maintenance on a weekly basis:Ceiling and wallsMaintenance on a weekly basis:ClosetsFridgesDate and name of person

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    BenchesNon porous covering, easy to clean and resistant to chemicals and disinfectants (Chlorine, etc.)No wood, no steelGlass, ceramic tiles, etc.

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  • 2. Know the risks

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    The risks Most Frequently Reported Infections in US, 1979-1999

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    LAIs in US, 1979-1999

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    Most Common Routes of ExposureInhalation of aerosols generated by accident or by work practices Percutaneous inoculationContact between mucous membranes and contaminated materialIngestion

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    AccidentsUse of needles and syringesSpills and spraysInjuries with broken glass or other sharp objectsAspiration through pipettes Bites or scratches of animals or ectoparasites

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    Injection Preparation Table,1998No re-use of disposable injection equipment

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    Example: recaped syringes 2003

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    Example: mouth pipetting2005

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    Aerosols and droplets are main sources of contamination

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    Episodes of Single-source, Multiple Laboratory InfectionsReitman and Wedum, 1956

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    Aerosols from laboratory equipment(1010/ml culture 10 min. use)Blender, opened at once106Sonicator, with bubbling106Pipetting, vigorous106Dropping culture3 x 105Splash on centrifuge rotor105Drop spill on zonal rotor2 x 104Blender, opened at 1 minute2 x 104Pipetting, carefully104 Dimmick et al., 1973

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    Aerosols from Animal Cage Cleaning

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    Contamination risks on biological samples

    Samples performed by the patient Stool Urine SputumExternal contamination of sample vialSamples performed by professional Pus CSF Nasopharyngeal aspirate or bronchoalveolar lavage Nasopharyngeal swab or throat swab BloodRisk at sampling ( needle, contact with skin specially in case of wounds). External contamination of sample vial

  • 3. Importance of using appropriate biosafety equipment

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    Using appropriate biosafety equipmentEach and every Biological sample is potentially infectious It is a risk for every person who will handle itDuring samplingDuring transportAt the openingDuring handling in the laboratory

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    Personal Protective EquipmentsGlovesCoatMaskGlassesScreenBiosafety cabinets ?

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    Precautions during sample collectionProtect collector, colleague, staff...wear gloves, coat, (mask, glasses) VHF: double gloves, filter-masks, bootsdispose needles in special containers, without re-capping, disinfection (sodium hypochlorite 2.5%), incinerationclean working surfaces (hypochlorite)decontaminate material (hypochlorite 10%)

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    During sample collectionConsider each sample as infectious Clean outer tube with 10% diluted household bleach (chlorine)Wear gloves (two layers)Wear lab coat, mask and protective glasses,Use evacuated tubes (vacutainers) for blood sampling

    Organize and disinfect bench space with Chlorine 10% followed by wash with 70% alcoholClean spills with Chlorine 10%Decontamination of equipment by Soaking in Chlorine10%

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    Preparation and handling of samplesOpening under Biosafety CabinetUse paper or cotton soaked with ethanol 70% to handle the cap when opening the tube (this will stop contamination by liquid droplets)Centrifuge at low speed before opening if liquid is spread all over the tube: check the centrifuge before, balance the tube and use capped buckets.Never use glass pipets for handling the specimens.No mouth pipetting allowedIf viruses are involved, freeze the aliquots as soon and as cold as possible.For bacteriology keep samples at room temperature

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    In all diagnostic and health-care laboratories; Sharp containers Specific waste disposal Never manipulate directly broken tubesManipulation of sharps and needles

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    Waste disposal

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    Good Biosafety PracticesThree critical steps

    TargetSourceTechniciansSamplesSupport staffEnvironmentSamplingTransportOpeningHandling in labWaste disposal

  • 4. Four biosafety levels

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    Risk Group I Low individual and community riskA microorganism unlikely to cause human or animal disease

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    Risk Group IIModerate individual risk, limited community riskA pathogen causing human or animal disease unlikely to be a serious hazard to laboratory staff, the community, livestock or the environmentMay cause serious infection but effective treatment is available and risk of spread is limited

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    Group II Examples Viruses, fungi, parasites, bacteriaLegionellaShigellaHepatitis B

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    Risk Group IIIHigh individual risk, low community riskA pathogen producing serious human or animal disease but not readily transmitted to others

    Effective treatment available

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    Group III examples Viruses, bacteria, fungiSARS and rabies virusBrucella speciesBacillus anthracisYersinia pestisMulti Drug Resistant Mycobacterium tuberculosisH5N1

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    Risk Group IVHigh individual and community risk

    A pathogen producing serious human or animal disease, readily transmitted from one individual to another.

    Effective treatment usually not available

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    Group IV ExamplesVirusesEbolaNipahHendra

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    Factors To Consider In ClassificationPathogenicity of the agentModes of transmission and host range of organismLocal availability of preventive measuresLocal availability of effective treatment.

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    Biosafety levelsAssignment of agent must be based on risk assessment. Depends on agent and conditions of useRequires professional judgment

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    Elements of ContainmentPrimary containment Protection of personnel and the immediate laboratory environment.Use of laboratory practices, techniques, safety equipmentSecondary containmentProtection of the environment external to immediate laboratory

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    Risk Groups vs. Biosafety Levels (1)BSC= Biological Safety CabinetGMT= Good Microbiological Techniques

    * Laboratory Biosafety Manual, 3rd edition, 2005 .

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    Risk Groups vs. Biosafety Levels (2)BSC= Biological Safety CabinetGMT= Good Microbiological Techniques

    * Laboratory Biosafety Manual, 3rd edition, 2005 .

  • 5. Risk assessment

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    RiskRisk of infection is defined as chance of exposure to hazard or exposure to chance of injuryRisk of infection may be quantitative or qualitative

    Laboratory Directors responsibility

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    Criteria for risk assessmentPathogenicity (the ability to cause disease) and disease severityInfectious dose (lower the dose, the higher the hazard)Transmission (the importance of aerosols) and agent stability in the environmentVolume and concentration (risk increases)Laboratory activity planned, including potential genetic manipulationPresence of suitable hostProphylaxis (local availability of vaccine or treatment) and medical surveillance

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    If limited information on agent or specimenUse standard precautions Use basic containment - BSL 2Follow national/international regulations for transportAssess medical dataGet epidemiological dataDetermine geographical origin of agent

  • 6. Appropriate biosafety documentation

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    Awareness, Training, VigilanceAwareness Advise workers of possible exposures, safeguards and responsibilitiesTraining Inform workers of hazards of their work, and use of appropriate practices, techniques and proceduresVigilance Maintain vigilance to guard against safety procedure compromise or errors.

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    Good biosafetyGood laboratory practicesAwareness of hazardsKnowledge of how laboratory infections occurKnowledge of procedures and techniques to reduce hazards

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    But alsoBiosafety Officer

    B