Observations on the use of Vaccines to assist control of Salmonella Enteritidis in Poultry Rob Davies Department of Food and Environmental Safety Veterinary Laboratories Agency Weybridge Addlestone Surrey KT 15 3 NB [Data derived from DEFRA/FSA funded surveillance and research] Sweden. Vaccine 06. ppt Slide 1
Agenda n Vaccination for SE in the UK n VLA research on vaccination and SE on laying farms n Problems with vaccine administration Sweden. Vaccine 06. ppt Slide 2
Not all reported incidents were confirmed. Sweden. Vaccine 06. ppt Slide 4
Not all reported incidents were confirmed. Sweden. Vaccine 06. ppt Slide 5
Salmonella Enteritidis and Typhimurium in chickens in G. B. End Treatment broiler parents SE Vaccination Breeders Sweden. Vaccine 06. ppt Slide 6 SE Vaccination Layers Live MD Vaccs 9 R Auxotrophic Vaccs
Laboratory reporting of salmonellas in humans in England Wales 1982 – 2003 (Bob Adak, HPA) Vaccination (commercial layers & end Br. Breeder treatment) Vaccination (breeders)
Commercial Laying Flocks Problem Monitoring sensitivity Potential Improvement - undetected infection - optimised bulked faeces, dust, egg collection systems - sensitive test methods Multi-stage sites - ongoing foci of infection Ideally empty site for: - egg belts/dung belts/scrapers - full decontamination - high stocking density/dust output - better biosecurity between houses - farm pest harborage - improved pest control - improved vaccination for S. Enteritidis (administration/efficacy) - ? S. Typhimurium [S. Infantis, etc] S. Typhimurium [S. Infantis, - vaccination plus competitive exclusion Persistent contamination within house - insufficient cleaning - audit cleaning contractors to ensure higher standard - insufficient drying - dry - house fans - choice of disinfectants - intensive formaldehyde/FGQ + fog - insufficient volume/concentration - include deep pits, belting outside house, etc saturation - better drinker design -insufficient pest control – mice/rats - sufficient baiting points in/around house + perimeter - flies - always fresh bait - red mite - traps/contact rodenticide - (litter beetles) - intensive baiting when house emptied - fly control in manure/airborne Sweden. Vaccine 06. ppt Slide 8 - red mite control
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Introduction of Live SE Vaccination on Previously Unvaccinated Farms – SE Infected flocks after vaccination Key: CO = not all in/all out Sweden. Vaccine 06. ppt Slide 12 MO = moulted flocks ROD = SE gone when rodents controlled
Vaccination and Salmonella status on large unit sampled for first time - March 2007 n Barn flocks – live vaccine – 2/2 + n Cage flocks – live vaccine – 7/7 + n Cage flock - no vaccine (oldest flock) -ve Sweden. Vaccine 06. ppt Slide 13
UK Prevalence Survey: Effect of Vaccination Sweden. Vaccine 06. ppt Slide 14
Observed SE Holding Prevalence by Flock Vaccination Status in EU, 2004 -5 Sweden. Vaccine 06. ppt Slide 15
Salmonella Control – Additional Measures n Water acidification – esp. pre and post depop/repop in layer house n Feed treatments – acids/formaldehyde n Competitive exclusion – ‘day old’/transfer n Vacuuming dust/air disinfection – Chloramine T, etc. n Disinfection – Acidic red mite spray - 5% formalin to saturation [downtime] n Rodents/insects/arthropods – chemicals/traps/tidiness Sweden. Vaccine 06. ppt Slide 16
Problems identified with killed vaccine administration n Inaccurate calibration of vaccinating gun n based on 1 x 0. 5 ml only n Incorrect vaccination site – close to ‘achilles’ tendon - post injection problems - vaccine leakage n Vaccination too fast n 2 handfulls of 4 birds in few seconds n missed doses n gun may not fully refill n leakage from injection site Sweden. Vaccine 06. ppt Slide 18
Problems identified with administration of live vaccines n n n n Poor refrigeration of vaccine Dirty mixing equipment Disinfectant in mixing area No use of stabiliser Use of 2 dose SE when known SE on farm Miscalculation of dose/water intake (variable by age and conditions) Inaccessible water tanks / poor mixing Water tanks insufficient capacity insufficient time for all birds to drink and get full vaccine dose n Bell drinkers ‘topped up’ with insufficient volume for too short a time & dirty water n Water lines not drained (or fully drainable) n No water withhold prior to administration n Water lines not primed with vaccine – use carrier dye n Poor quality water – bore hole n Antibiotic use – inc. at hatchery Sweden. Vaccine 06. ppt Slide 20 n CONSULT THE VACCINE COMPANY SPECIALISTS !
Conclusions n Vaccination for S. Enteritidis very successful in breeding flocks and all in – all out production n Reduced prevalence in birds and eggs in persistently infected flocks n Live vaccines increased total vaccine uptake in National Flock n Vaccines must be administered with great care n Vaccination is not a substitute for good management – especially effective rodent control Sweden. Vaccine 06. ppt Slide 21
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