Enteric Zoonoses On Farm strategies for prevention

1. Enteric ZoonosesOn Farm strategies for prevention Dr. Paul Kitching Chief Provincial Veterinarian Director Animal Health Branch BC Ministry of Agriculture and Lands October 22, 2009

2. Todays Topics • Overview of meat, milk, egg production in BC • Enteric pathogens– are they the same for animals and humans? • Case studies: E.coli O:157 and SE • On farm measures to reduce pathogens • Summary

3. Meat, Milk and Egg Production in British Columbia • Supply managed (quota system) : $1.6 billion; 28,000 jobs • Table eggs • Chicken meat/products • Turkey meat • Milk / Dairy • Other • Beef (cow/calf ranching, feedlots) • Pork (swine operations) • Large part of BC economy: • Subject to total devastation during animal disease crisis. • Small scale production occurs especially in rural areas

4. Beef Production in BC • 4086 beef cattle ranches in BC -598,500 cattle (Bulls, Cows, Calves, Steers, & Heifers) (4.3% of Canadian herd) -269,325,000 lbs. of beef produced annually • British Columbia Beef Consumption /year = 207,916,000 lbs. [Avg 47.2lbs of beef consumed per person annually (Statistics Canada 2008)] • Export market for British Columbia’s Cattle & Beef

5. BC pork production • 31 registered swine production farms in BC • > 200,000 market hogs / year • Most of the pork consumed in BC is imported from other provinces and US Is it Safe? • Influenza in swine herds is reportable to CVO- no cases have been reported since 2008. • June 2009: WHO/ OIE/ FAO- The risk of being infected with swine influenza viruses through the consumption of pork or pork products is negligible. Influenza viruses are generally restricted to the respiratory tract of pigs and are not detected in the muscle (meat) of pigs, even during acute illness.

6. Milk production in BC • Approx. 560 dairy farms • 67% Fraser valley • 17% OK • 10% VI • Caribou, Kootneys, Peace • 652,231,187 total litres of milk produced /year August 2007-July 2008 • Routine sanitation practices: • Cleaning and flushing milk machines • Sanitize and dry teat before milking • Separate animals with mastitis – milk not added to bulk tank • Manure, feed, housing management • Bacterial cell count on every tank • PASTUERIZATION!

7. Poultry and Eggs • 325 chicken farms in BC produce about 158 million kilograms of meat /year • 64 turkey farms in BC produce about 21.3 million kilograms of meat • 129 table egg farms in BC produce about 61.8 million dozen eggs Ref: http://www.bcegg.com/files/documents/BACKGROUNDERBCDEPIsocioeconomicimpactstudy.pdf

8. Food-borne Pathogens Animals are not sterile. The environment is not sterile. Foods without bacterial kill steps (pasteurization, irradiation, thorough cooking) can have risks

9. Reservoirs of Enteric Zoonoses • Animal reservoir • Campylobacter (poultry) • Salmonella spp. (poultry, cattle, reptiles, wildlife etc) • E. coli 0157:H7 (ruminants- esp. cattle, deer) • Cryptosporidium (young calves, wildlife) • Giardia (wildlife, humans, animals) • Yersiniapsuedotuberculosis and enterocolitica(wildlife, birds, pigs) • Human reservoir: i.e. Norovirus, Shigella

10. Route of transmission • Enteric pathogens: ingestion • Usually fecal- oral contamination • Animal to animal [Environment] • Animal to human • Some pathogens can contaminate the product Eggs: Salmonella enteriditis ANIMAL AGENT ENVIRONMENT HUMAN

11. Reportable enteric zoonoses Poultry • Salmonella pullorum • Salmonella gallinarium Mammals Humans • Salmonellosis (all serotypes) • Campylobacterosis • Verotoxigenic E. Coli • Cryptosporidiosis • Yersiniosis

12. Farm to Fork • Contamination can occur at several points along the food chain • On the farm • Irrigation of crops • At the slaughter plant • During processing • At the point of sale • During preparation

13. E. coli O157: H7 on farm

14. E.Coli O157 :H7 • E.Coli O157 :H7 are intestinal bacterial flora of ruminant animals, including cattle, goats, sheep, deer, and elk. • A major source of human illnesses is consumption of undercooked ground beef. • E.Coli O157 :H7 that cause human illness generally do not make animals sick. • Other kinds of animals, including pigs, small mammals, and birds, sometimes pick up E.Coli O157 :H7 from the environment and may spread it.

15. Excretion Re-colonization Environment E.Coli O157 :H7 • Cattle are primary reservoir: • large intestine, recto-anal junction • warm, constant • nutrient rich • vigorous growth • Environmental spread: • water, soil, sediment • cool, fluctuating • nutrient limiting • survival

16. E.Coli O157 :H7 on Farms • Cattle are asymptomatically colonized- transient and common intestinal flora • Seasonal- summer peak, winter nadir • Endemic and fluctuating populations- feedlot, pen, farm, week • Intermittent isolation - feces, hide, oral cavity

17. Evaluate farm interventions to reduce fecal shedding of E.coli O157 in domestic ruminants • Systematic Review done in 2007 by PHAC and McMaster U Interventions: • Probiotics • Vaccination (new product) • Antimicrobials • Results: Evidence of efficacy • Probiotics • L. acidophilus NP51 + P. Freudenreichii • Sodium chlorate • Vaccination- not consistent • Antimicrobials – no evidence to support use for this purpose Sargeant et al. Pre-harvest Interventions to Reduce Shedding of E.coli O157 in the faeces of weaned domestic ruminants: Systematic Review Zoonoses and Public Health 2007; 54(6-7):260-77

18. Salmonella • More than 2000 serotypes • About 30 are very common in poultry, others are found in cattle, reptiles, etc. • Salmonella spp. are primarily intestinal flora • Salmonella spp. generally do not cause disease in reservoir hosts: poultry, adult cattle, reptiles but can cause disease in horses, pets, humans and many other animals.

19. Salmonella enterditis (SE) • S. Enterditis invades hens reproductive tract leading to contamination of the egg. • SE is well adapted to rodents and chickens • Easily transferred from hen to chick and environment • Transmitted to humans during consumption of undercooked eggs

20. On Farm Strategies for reducing SE • Routine Testing for Salmonella enterditis • Identify infected flocks: Swab and culture environment • Control: divert eggs/depopulate/clean premise • Vaccination- • Varying effectiveness • Control of rodents, wild birds- very important • Purchase feed from supplier (CFIA tested) • All in/all out- no mixed ages, periodic empty premise • Regular thorough cleaning and disinfection of premises • Start with SE free birds

21. On farm strategies to control pathogens:Veterinary supplements and drugs • Probiotics • Management and judicious use of veterinary drugs: • Withdrawal times for milking and meat animals (according to known breakdown and excretion of the drug) • Controversy about antimicrobials used for prevention

22. British Columbia’s Biosecurity programs • Mandatory in regulated poultry industry • In development for swine • Purpose: reduce risk of infectious disease transmission within and among flocks, animals. • Components: • Farm Access Standards (roads and gates, signage, vehicle decontamination) • Barn Access Standards (anteroom, restricted access) • Flock Health Management (records, recognizing illness, introduction of new animals, diagnostic sampling, mortality, disposal) • Farm Management (manure, pest control, cleaning/decontamination, producer and employee training, SOP’s ,visitor log)

23. On Farm Food Safety/Best Practices Programs • Production programs based on HACCP principles: • Beef: Quality Starts Here and Verified Beef Production • Chicken: Safe, Safer, Safest (On Farm Food Safety Assurance Program) • Eggs: Start Clean- Stay Clean • Milk: Canadian Quality Milk Program

24. Urban, backyard farms, small farms • Ongoing effort to improve disease detection in small flocks via training of veterinarians and seminars for small flock owners • BC Good Agricultural Practices manual • Target audience: unregulated farmers • Avoids technical terminology • HACCP based format • Assessment flow chartsdetermine GAPs implementation tools (who, what, where, how)

25. What we didn’t cover on food safety Post harvest Strategies: • Pasteurization- (kill step) • Grading- Eggs • Meat inspection at slaughter • Refrigeration • HACCP programs in processing • Irradiation (kill step) proper storage, handling, prep, cooking..

26. Summary • On farm strategies can reduce but not eliminate pathogens • Some pathogen monitoring and control programs in place: Milk- somatic cells, antibiotics; Egg- SE • Research being done to develop and evaluate more effective farm level interventions and vaccines • Increasing practice of biosecurity and on-farm food safety programs and standards • Provincial /Local foods: Chicken, turkey, milk and eggs produced in BC are consumed in BC • There is no food safety risk associated with influenza in pigs

27. Questions?