Biosecurity & Environmental Monitoring Univ of Surrey 2022.pdf

CODE: 10AM: XY-BM-ZP 11AM: IU-DQ-DF Biosecurity & Environmental Monitoring Grant Hayes LOs • To understand the following; – The aim of biosecurity and environmental monitoring – How to assess biosecurity standards – The different ways to monitor the environment and their limitations – Factors to...

CODE: 10AM: XY-BM-ZP 11AM: IU-DQ-DF Biosecurity & Environmental Monitoring Grant Hayes LOs • To understand the following; – The aim of biosecurity and environmental monitoring – How to assess biosecurity standards – The different ways to monitor the environment and their limitations – Factors to consider in designing environmental monitoring programs – How to interpret environmental monitoring assessments – Issues with multi-age sites 2 Biosecurity? • Biological • Security • “procedures or measures designed to protect the population against harmful biological or biochemical substances.” • • • • Disease prevention Hygiene Housekeeping Common sense!! • Aim to reduce potential disease introduction and reduce challenge levels Biosecurity Biosecurity • What you would (should) do to prepare for your relatives to come over for Christmas dinner?? • • • • • • Tidy up the clutter Hoover Dust Wipe kitchen surfaces Clean the toilet Clean towel, soap and loo roll • Tell them to take their shoes off when they arrive Environmental Monitoring • Health related assessments of animal environment usually related to biological assessments and not management or environmental eg ventilation • Aim to risk assess the existing health/disease status that livestock is being introduced to or is living in. Environmental Monitoring Risk assessment • Paired with Health monitoring – Health assessments of the animal itself • Provides a risk assessment of the disease/health status of the site eg – Salmonella positive – S.typhimurium positive – LPAI positive Risk assessment • Health monitoring, environmental monitoring and biosecurity combine to provide a risk assessment of the status of the livestock site for both existing disease status as well as identifying risk of introducing disease or increasing disease challenge. Practical Biosecurity • State of mind – – – – – Warning signs Warning tape Health statements Sign in book Space/air/driveway • Stop and think • Physical – – – – – – Fence Gate Wall/door Foot dip Hand sanitiser Shower • Stop and do Infection Transmission • True airborne – Rare • Small viruses mainly • Short distances generally (AI 50m) – Can be an issue in very densely populated livestock areas • Chicken alley in Lincs! “If Salmonella were as big as broomsticks we would walk around and pick them up!” • “Walked onto site” – People • Hands, footwear • (Mycoplasmas survive in nares) – Vehicles • Chicken catchers • Trailers – Equipment • Vaccination teams • Egg trays – Livestock • Multi age • Bought in – Vermin – Insects Biosecurity Design • Perimeter barriers – Fence • Controlled perimeter access – Locked Gate • CCTV • Sign in book – – – – Vehicle wash Changing room Footdips Hand & equipment sanitiser • Point of disease entry onto SITE (for livestock if extensive/outdoor eg free range) Biosecurity Design • House barriers – Double door • Controlled house access – – – – – – – Door locks Step over Demarcated areas Showers Changing room Footdips Hand & equipment sanitiser • Point of disease entry for housed Livestock Disease dilution from gate to animal Biosecurity Processes • • • • • • Site layout Fabric of the building Vermin control Insect control PPE Footwear policy – Colour coded boots! – Plastic overshoes!! – Rigger boots!!! • Hand sanitising policy • Fallen livestock moving and disposal • Deliveries • Maintenance – Who doesn’t sign in? • Clean out • Litter/slurry removal • Wash water removal Biosecurity Processes • Issues; – Footdip de-activation • Organic matter • UV light (Virkon S) • Rain dilution – Hand sanitisers • Alcohol based – Coccidial oocysts?! – Are they full?? – How rigidly do all visitors adhere to policies on site • Employees • Delivery drivers • Maintenance teams – Often want to wear own clothes,boots!! • OOH checks • Emergencies – Single age sites • Must clean PPE, biosecurity equipment at clean out – Multiple site or multi age site policies? • Disasters!!! Clean Out Process Clean out Process Clean out efficacy • • • • • • • Clean inside Clean outside Maintain/repair inside Dry inside Disinfect inside (Fumigate inside) Disinfect outside – Beware cross over/reinfection • Disinfectant is left to dry • Drying is a disinfecting process • Disinfection is diluted if surfaces are not dry before application Environmental monitoring • Risk assessment • Visual and microbiologically assessed hygiene check – Looks dirty, is dirty… – Looks clean, may be clean….. – Tests clean, is clean….. • Define what is acceptable as “clean” enough to pass – Sterile?? • Farm environment not operating room – Specific pathogen free • Salmonella – Maximum microbial load Environmental monitoring What is to be monitored? • Bacteria – General levels eg TC – Specific eg salmonella • Parasites – Ecto eg Red Mite, Mange – Endo eg Ascarids, coccidia • Vectors – Eg beetle • Yeast & Moulds • Viruses – Rarely but cause much disease! Environmental monitoring How is it to be monitored? • Presence or absence (+ve/-ve) • (Semi-)Quantitative (A,B,3x10¹) • Laboratory – Bacterial culture – PCR • On site – Visual assessment – Skin scrapes – 3MATPase • False –ve/False +ves • Compare to set targets or look for an improvement? EM programme Tailor to; Sample sources • Site history • Fabric of building – Coccidiosis • Marketing schemes – ACP TVCs 1 shed • National legislation – DEFRA Broiler salmonella testing • Veterinary Health Plan/performance improvement plan – Red mite population – Floors – Fans – Drinkers • Inputs into shed – Feed deliveries – Water quality – Moveable Equipment • Catching crates • Trailers – People • Exotic holidays • Contact with other livestock • Vets!! Inside ….and outside! EM testing Define Aims • Freedom from specified disease pathogens – Salmonella – Campylobacter – Coliforms • Assessment of general hygiene levels – TVC – Coliforms – Y&M EM testing Define Acceptance levels • Disease eradication – Legislated, marketing scheme, cost of disease • +ve/-ve result • Target –ve result • Maximise hygiene – Some TVC will be pathogenic – Limits disease challenge whilst immunity or age resilience develops – Limits co-infections – Improves performance • (Semi-)Quantitative • Target defined level eg » A,B (A-E) » <3x10³cfu/ml Test Methodologies • Ease of sampling • Test methodology – – – – – Specificity Sensitivity Speed Cost Legislated method eg DEFRA approval for salmonella testing EM scheduling • Pre-depletion – “Dirtiest” – Defines baseline • Pre-placement – “Cleanest” • Clean out process – Observation of processes – Informs of success of processes in terms of resulting EM results • Salmonella – Check pre-depletion – Re-check pre-placement Disinfectants • Final dilution of microbial environmental load • 1st stage=dry cleaning – Biggest dilution • 2nd stage=wet washing – Hot or detergent – Next biggest dilution • 3rd stage=rinsing detergent • 4th stage=Disinfection • Efficacy dependent on; – Fabric of surface eg wood, brick, metal, porous or not – % dilution – Time of activity – Temperature of activity – pH interactions • Must identify that the chosen disinfectant IS active at the applied rate, temperature, fabric and with the level of soiling likely against the target organism – Contact times & dilution rates recommendations vary with pathogen DEFRA Approval http://disinfectants.defra.gov.uk/DisinfectantsExternal/Default.aspx?Modul e=ApprovalsList_SI Disinfectant Product Recommendations EM Results Pre-Placement EM Results growout Summary • The aim of biosecurity and environmental monitoring • How to assess biosecurity standards • The different ways to monitor the environment and their limitations • Factors to consider in designing environmental monitoring programs • How to interpret environmental monitoring assessments • Issues with multi-age sites • Maximise protection, assess risk to protection • Disease dilution from the entry point, visual • Specific pathogens freedom or hygiene assessment to assess microbial dilution • Bespoke programs, national & local disease status, cost, risk assessment • Specific pathogens freedom or hygiene assessment to assess microbial dilution • Disease cycling as site never clean 42