Disinfecting And Sanitizing Animal Facilities

Disinfecting And Sanitizing Animal Facilities

Levels Of Sanitation Clean Remove soil Requires soap to remove oils May need a descaler (acid wash) Remove 99 % of bacteria Improve efficacy Sanitize Reduce microorganisms to an acceptable level (99.9%) Disinfect Destroy infectious agents Sterilize Destroy all living organisms

Biosecurity All measures used to control all known or unknown infections in laboratory animals. (From the ILAR guide)

Biosecurity Levels Require sterility Axenic: Free of all known or measurable microorganism. Gnotobiotic: Having a defined list of microorganisms.

Biosecurity Levels Require minimum of sanitation; often more Specific Pathogen Free (SPF): Free of a defined list of microorganisms. Viral Antibody Free (VAF): Free of known viruses. Restricted Flora--Free of Opportunistic Organisms Requires sanitation Conventional: Clean environment but little or no effort to prevent exposure to microorganisms.

Cleaning Dumping cages requires protection for personnel from aerosolized allergens and potential biohazards. Mask Dump station

Washers Prewash: Removes loose soil Wash: Hot water and soap to remove soil and oils Rinse: Removes soap and sanitizes using hot water Temperature Versus Time 180 F for 0.1 second (Industry standard) 170 F for 1.5 seconds Final rinse and dry

Tunnel Washer Cages travel on a conveyor belt through the tunnel. Different sections perform the different phases of the wash.

Rack Washer Nozzles on either side oscillate. Nozzle on top. No nozzle from floor.

Cabinet washer Works like a dishwasher Cages must be stacked correctly so that water hits all surfaces.

Sterilizers Sterilization Moist heat: 250ºF for 15-30 minutes Dry heat 320ºF for 1 hour Moist heat: Autoclave Dry heat: Glass bead sterilizer for surgical instruments

Sterilization Gamma irradiation UV Light (no penetration) Filtration

Choosing the Appropriate Chemical Methods Requirements Organisms present Level of disinfection Toxicity Animals Humans Corrosion Use conditions location, timing

Factors Affecting Chemical Efficacy Method of application Sponge, mop, wipe Spray Immersion Fog

Factors Affecting Chemical Efficacy Dilution Follow directions Too little Reduces efficacy Too much Wasteful Potential for toxicity # of bacteria killed Toxicity Kill rate Concentration

Factors Affecting Chemical Efficacy Shelf life Time of exposure Organic soil load Temperature Humidity Hard water salts ph Incompatible chemicals

Sanitizer/Disinfectant Generally effective against most bacteria Most are not effective against Micobacterium tuberculosis Generally effective against enveloped viruses Most are not effective against non-enveloped viruses Not effective against spores

Sanitizer/Disinfectant Used on equipment and animal quarters Quaternary Ammonia Compounds (QAC) (Alkyl dimethyl ethybenzyl ammonium chloride) Excellent cleaning ability Sticky residue, must be rinsed Phenolics (pine cleaners) Good cleaning ability Sticky residue, must be rinsed Toxic to cats

Sanitizer/Disinfectant Used on skin & wounds Alcohol Poor cleaning ability Doesn t leave a residue, rinse is not required Used as a rinse in the surgical prep Also used to remove water from surgical instruments Iodine Fair cleaning ability Inactivated by organic matter, heat and UV light Iodine is irritating, staining, and toxic Iodophors (povidone-iodine), like Betadine, are not Used as a surgical prep: Betadine scrub and solution

Sanitizer/Disinfectant Used on skin and equipment Chlorhexidine DSN Dilute Nolvasan Solution (3%): Topical disinfectant for skin lesions Chlorhexidine scrub and solution can be used as a surgical prep (like Betadine) Can also be used to clean instruments, surgical areas, and animal quarters.

Sanitizer/Disinfectant Bleach (sodium hypochlorite) Used on inanimate objects and to disinfect water (16 drops/gallon) Excellent, and cost effective, disinfectant but often misused Poor cleaning ability, low penetration, must wash items first Not stable at use dilutions Inactivated by organic matter as well as heat and UV light Corrosive to metals--rinse required

Disinfectant/Sterilant Must be able to kill all microorganism, including spores Difference between levels may be based on concentration and/or contact time. Not usually stable at use dilutions

Disinfectant/Sterilant Used to sterilize equipment Chlorine dioxide Poor cleaning ability Inactivated by organic material Corrosive to metal--rinse required Peroxygen Compounds (Paracetic acid and hydrogen peroxide) Fair Cleaning ability Corrosive to metal rinse required

Sterilant Aldehydes Used to sterilize empty rooms--aerosol Poor cleaning ability Requires a long contact time Inactivated by organic matter Toxic Irritating and carcinogenic

Validation and Monitoring Indicators Environmental screening Proves ongoing effectiveness of products and procedures Methods RODAC plates (Replicate Organism Detection and Counting) Swabs ATP detection test

Odor Control Unacceptable method Masking binding to olfactory receptors Acceptable method Destruction of odor-causing organisms

Pest Control Identify the pests Insects Arachnids Rodents Birds Reptiles

Pest Control Types of Control Available Build them out Monolithic construction Repair access points Cracks, door seals

Pest Control Types of Control Available Build them out Monolithic Barriers

Pest Control Types of Control Available Build them out Monolithic Barriers Sanitation Clean drains No standing water No clutter: cover material that can t be cleaned

Pest Control Program Pest control methods Traps: Fly lights Rodent traps: live traps must be checked daily Bait stations: inside vs outside Boric acid: desiccant Pesticide sprays: only outside Pyrethrum Routine program Requires documentation Fly light