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LABORATORY FACILITIES AND SAFETY. Problem Scenario.
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Problem Scenario • Your 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?
Organization Personnel Equipment Process Control (Quality Control & Specimen Management) Information Management Purchasing & Inventory Occurrence Management Assessment Documents & Records Process Improvement Customer Service Facilities & Safety The Quality System
Learning Objectives At the end of this activity, you will be able to: • Discuss the importance of laboratory design • Know what, where and when the risks are • Discuss the importance of using appropriate biosafety equipment • Describe the four biosafety levels • Outline factors that need to be considered when assessing risk • Keep appropriate biosafety documentation
Laboratory design • 1-Path followed by the sample: • Reception and registration of patients • Sampling rooms • Dispatch between different laboratories • Analysis of samples • Results • Delivery and filing of results • Related services: Secretariat, Offices, Washery, Preparation and sterilization, Storage, Cold room.
Premises • Reception : > reception and registration of patients > reception and registration of samples from other departments • Sampling rooms > samples and sorting of samples
TOTAL AREA 104 M2 Common room, stairs to offices Plan Gynaecological specimens Blood clotting Washroom Blood specimens Haematology Biochemistry Reception and administration ENTRANCE Bacteriology Disinfection
Service rooms • Washery with autoclaves for sterilization, wash and dry of glassware • Preparation, sterilization and distribution of culture media and reagents • Stock room • Cold room • Culture room • others
Premises • High ceiling • Walls and ceiling with glossy paint : easy to clean and disinfect. • Floor easy to clean and disinfect
Access to premises • Only authorized persons: technicians, biologists, and maintenance staff ( badges)
Safety during service No unauthorized persons No friends No children No animals Please OPEN AND CLOSE
Premises cleaning • Maintenance on a daily basis: • Benches • Floor • Maintenance on a weekly basis: • Ceiling and walls • Maintenance on a weekly basis: • Closets • Fridges • Date and name of person
Benches • Non porous covering, easy to clean and resistant to chemicals and disinfectants (Chlorine, etc.) • No wood, no steel • Glass, ceramic tiles, etc.
The risksMost Frequently Reported Infections in US, 1979-1999
Most Common Routes of Exposure • Inhalation of aerosols generated by accident or by work practices • Percutaneous inoculation • Contact between mucous membranes and contaminated material • Ingestion
Accidents • Use of needles and syringes • Spills and sprays • Injuries with broken glass or other sharp objects • Aspiration through pipettes • Bites or scratches of animals or ectoparasites
No re-use of disposable injection equipment Injection Preparation Table,1998
Episodes of Single-source, Multiple Laboratory Infections Reitman and Wedum, 1956
Aerosols from laboratory equipment(1010/ml culture – 10 min. use) Blender, opened at once 106 Sonicator, with bubbling 106 Pipetting, vigorous 106 Dropping culture 3 x 105 Splash on centrifuge rotor 105 Drop spill on zonal rotor 2 x 104 Blender, opened at 1 minute 2 x 104 Pipetting, carefully 104 Dimmick et al., 1973
Contamination risks on biological samples • Samples performed by the patient • Stool • Urine • Sputum External contamination of sample vial • Samples performed by professional • Pus • CSF • Nasopharyngeal aspirate or bronchoalveolar lavage • Nasopharyngeal swab or throat swab • Blood Risk at sampling ( needle, contact with skin specially in case of wounds). External contamination of sample vial
Using appropriate biosafety equipmentEach and every Biological sample is potentially infectious It is a risk for every person who will handle it During sampling During transport At the opening During handling in the laboratory
Personal Protective Equipments • Gloves • Coat • Mask • Glasses • Screen • Biosafety cabinets ?
Precautions during sample collection • Protect collector, colleague, staff... • wear gloves, coat, (mask, glasses) • VHF: double gloves, filter-masks, boots • dispose needles in special containers, without re-capping, disinfection (sodium hypochlorite 2.5%), incineration • clean working surfaces (hypochlorite) • decontaminate material (hypochlorite 10%)
During sample collection • Consider 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% alcohol • Clean spills with Chlorine 10% • Decontamination of equipment by Soaking in Chlorine10%
Preparation and handling of samples • Opening under Biosafety Cabinet • Use 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 allowed • If viruses are involved, freeze the aliquots as soon and as cold as possible. • For bacteriology keep samples at room temperature
Manipulation of sharps and needles In all diagnostic and health-care laboratories; • Sharp containers • Specific waste disposal • Never manipulate directly broken tubes
Good Biosafety Practices Three critical steps