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Craig Stephen DVM PhDCentre for Coastal Health and
Department of Ecosystem and Public healthUniversity of Calgary
http://foodfreedom.wordpress.com/2010/09/01/5-reasons-why-chickens-belong-in-your-city-town-or-neighborhood/
Unacceptable? Acceptable?
http://www.theepochtimes.com/n2/content/view/19992/
http://www.sandiegopersonalinjuryattorneyblog.com/dog-bites/
Chicken Little and the problems of risk perception◦ Urban chickens are ‘new’
Pet dogs are ‘old’◦ New has less baseline data
Uncertainty in scienceHigher risk perceptions
What makes something risky◦ Science based
Exposure and magnitude◦ Societal based
Perceptions
http://we-make-money-not-art.com/archives/wearable/index.php?page=6
http://www.tru.ca/its/infosecurity/Risk_Analysis.html
The biggies - Salmonella and Campylobacter◦ What % of these cases in people are attributed to
poultry?Of these – what were the mechanisms of exposure?
Other Bacteria◦ Avian TB complex, Erysipelas, Listeria, E.coliChlamydia – PscittacosisParasites – Cryptosporia (?)Fungi – Cryptococcus, HistoplamosisViruses◦ Equine encephalitis◦ Avian Influenza
It is easy to make a hazards listHard to quantify frequency and probability of:◦ Backyard chicken
infection and shedding rates
◦ Environmental contamination
◦ Viability of pathogens in backyard coops
◦ Human contact rates of backyard chicken associated pathogens
Rare but catastrophic = big risk perception
Would this be a controversy without AI?◦ Chickens, people, cities =
formula for AI in AsiaSignificant international and national impacts◦ See next slideWhat is the likelihood AI would be linked to backyard chickens
Costs Example AmountDirect Federal compensation to farmers $64 million
Outbreak response and control $7.4 millionOpportunitycosts
Lost revenue from poultry sales $380 million
Lost feed sales $74 million + 2 mills close
Social costs Jobs lost 1700 (700 poultry workers apply for EI)
Food bank visits Increase by 500 visits/mos July and Aug
Unmeasured Federal and provincial operating costsEmotional impacts
Burns et al (PhD. Ont. Vet. College 2010)◦ BC backyard flocks isolated nodes from a
commercial bird transmission perspectiveHeterogeneous – 2 highly connected backyard flocksBasic biosecurity precautions rare
◦ Birds did move (to shows, sales, swaps)A risk for AI in other countries
◦ Low uptake of vet services (approx 3% in US study)
Dealer(n=1)
Breeding Stock
SlaughterCull Birds(excess roosters old birds)
Young Adults
Chicks
Hatching Eggs
Other Flock
Shows
Auction
Young Adults
Chicks Retail Store (pets, ornamental)
?
1.
88% had a negative view of government◦ disapproval of government disease control policy◦ distrust of government’s competency in
implementing policiesHid and smuggled birds during the AI outbreakWhy?◦ Perceived the risks to be less from the birds to be
small◦ Highly valued their birds and ability to raise them
Rejection of intervention
High interest in avian influenza
Low interest in avian influenza
CompliantNoncompliant
Weakly Compliant/ Unwittingly noncompliantWeakly noncompliant/
Unwittingly compliant
Minimize effort to comply
Change control policiesImprove incentivesEnforce regulations
EducatePromote
Majority of study participants
Minority of study participants
Acceptance of Intervention
Chickens are good Chickens are bad
Food safety◦ Control of drug use◦ Less disease (perceived)Food quality◦ “better’ eggsFood security◦ Produce own foodEnvironmental impact◦ Less egg transport◦ Chickens for weed controlHuman animal bond
Nuisance to neighboursWaste attracting pestsDiseases◦ Public health (Zoonoses)
Food safetyWaste handling
◦ Animal health (reportable disease)
Uncontrolled and unaccounted
“The public health risks and benefits from backyard poultry cannot be declared based on evidence but instead must be judged on opinion and analogy”
◦ The risk of pathogen transmission appears to be mild and does not present a greater threat to the public’s health compared with other animals such as dogs and cats.
All animals carry pathogens (just like people)Minimal to no data on source attribution of human illness of zoonotic agents◦ Proportional risk from animals = ?Many are either asymptomatic, mild, self-limiting or treated symptomatically◦ Hard to estimate environmental and case burdenNo work done of exposure◦ How much animal contact is enough◦ No exposure = no risk
Other cases with little data, biologically plausible but unmeasured risk, and marginal or limited social benefits
◦ Cases from the CCH filesDoctor fish and personal services establishmentsRaw goat milk consumptionCanada geese and environmental fecal contaminationInvasive bullfrogs and water safetyQ-fever in goatsPublic interactions with zoo/aquarium animals
Can’t do evidence based risk assessment
Conflicting risk perceptions
Precautionary stance of public health◦ When in doubt, act to protect
Desire by growing segment of the public for reduced external control over food and personal decisions
Help people make a good decision◦ Decision making and uncertainty◦ Expert decision making models
Multi-criteria decision analysis
Help people behave in a way that is good for public health◦ Behaviour change model of health promotion
What do we usually do?◦ Ask the expert in a non-systematic way
Meta-analysis doesn’t work as thee scenarios not studied
Decision makers – similar processes/issues◦ Know the goal◦ Know positive and negatives◦ Able to make the decision◦ Peers would see this as a good decision◦ Trust those people who help you with the decision
making
Legislation◦ What is currently legal
Animals = commodities; legislation usually around major animal industry (food safety, limited zoonoses)
Consultation◦ With public◦ With others
Health Canada health goals includeHealthy environmentsSupporting personal choices to enhance health
Other public health goalsDisease and injury prevention
What do to when they conflict?
Animal welfare◦ Education and capacity of
backyard farmers for animal care
Risks to wild birds◦ Birdfeeders and
unintended consequences◦ What about poultry
feeders?Genetic diversity of a species (domestic chickens)Does human illness always win?
29
Omega fatty acids vs species extinction
Minimize the harms◦ EID preparedness,
response and control◦ Endemic zoonoses
Poverty, food safety, lost productivity etc
◦ Sentinels for environmental toxins◦ Chemical food safety◦ Degradation of
environmental services
Maximize the benefits◦ Sustainable food
(domestic and wild)◦ Rural economic
development through animal services◦ Cultural goods from
animals and environment◦ Robust and resilient
environmental services◦ Biodiversity
Pollock et al – really no data for the positives◦ Not really a food security or environment issue
Might actually increase greenhouse gas/eggCost per egg will be highAffluent people (homeowners) will raise chickens
◦ Food safety and disease controlUnmeasured but Burns work suggests care may be lower
But is exposure higher?◦ Personal autonomy and human animal bond is the
greatest benefit
Team-based decisions Optimal decisions
Data poor so cannot calculate optimal riskNeed to consider the unanticipated effects◦ What are implications on
animal health◦ How does this in turn
affect social riskSocial valuesSystematic vs best approximation
A way to link values, data, goals through stakeholder and expert interaction◦ Advantage – transparent, participatory, builds
consensus◦ Problem – time, money and willingness to invest◦ Problem – doesn’t mean everyone agrees
Who participates Grey haired men around a table
Who to consult for animal-health-society issues◦ Who in public health
Health promotion, Communicable disease
◦ Home ownersFor and against
◦ VetsWhich ones – public vsprivate
Few vets know public health risk assessment
Workforce surveys◦ 80-90% in private
practice◦ 50% self employed◦ 10% in public services◦ 5% in educationWorkforce projections◦ CatsMost optimistic about alternative careers◦ Academics
Backyard chickens, raw milk, doctor fish – these are at the margins of public health◦ How much to invest in decision makingUsual case◦ Is it legal – if not – stop
Need big motivator to change the lawMost food safety and animal industry are regulated
◦ Is there reasonable evidence to show harms>benefitsHarms – usually poor published literature so need an expert consultation (get the right experts)Benefits – need to look fully at determinants of health
Usually dealing with issues of autonomy for many marginal animal issues
Ottawa Charter for Health Promotion◦ “Inextricable links between people and their
environment constitutes the basis for a socioecological approach to health”
need to encourage reciprocal maintenance - to take care of each other, our communities and our natural environment.
Rio Declaration◦ Peace, development and environmental protection
are interdependent and indivisible
Nutrition◦ Declines in fisheries reduced income and food
source and turns people to cheap less nutritious diets
Physical fitness◦ Out in the country gathering and huntingSpiritual valueNeed assurance for sustainable provisions of environmental goods for health
39
• Both healthy and infected animals were slaughtered
• Between 4 and 10 million cattle, sheep, pigs, goats and deer were culled
• Most farms affected: the outbreak cost farming at least 4 billion pounds
• Tourism also affected
40
• Higher rates of psychological morbidity in affected area compared with before the outbreak
• The level of psychological morbidity correlated with the degree of culling and restrictions
41
Social Capital: refers to both formal and informal reciprocal links among people in all sorts of family, friendship, business and community networks
In an Australian survey, pet ownership was found to be positively associated with some forms of social contact and interaction, and with perceptions of neighbourhood friendliness◦ Pet owners scored higher on social capital and civic
engagement scales
LEAST EVIDENCE AND HISTORY OF SUCCESS
Predicting emergence
Predicting a new zoonotic disease based on patterns of animal health, use or ecology
Detecting the index case
Proactive communication of sentinel events to public health
Investigating new diseases to assess theirrisk to people and to identify early clues for control
Tracking an emerging pathogen to provide local prediction of geographic spread
Control known or emerged animal diseases
Reducing human susceptibility through food security and rural community support
Creating resilient animal populations to reduce susceptibility and rates of disease
BEST EVIDENCE AND HISTORY OF SUCCESS
Since we are often dealing with opinion – is it a trusted opinion?Central at the International One Health Meeting◦ Build network of trusted peers now◦ Learn their world
Few vets understand public health apart from zoonoses and food safety
Tend to discount social determinantsFew public health folks understand animals as positive determinants of health
Or know risks to animals due to public health decisions
“a movement to forge co-equal, all inclusive collaborations between physicians, osteopaths, veterinarians, dentists, nurses and other scientific-health and environmentally related disciplines”
http://www.onehealthinitiative.com/
“when properly implemented, it will help protect and save untold millions of lives in our present and future generation”
No evidence that One Health is better◦ No systematic
evaluation of surveillance systems◦ No evidence based
governance◦ Interdisciplinarity =
hospital teams, systems engineers and business
Key Components◦ Shared framework
Common understanding of issues and goals
◦ Mobilizing teams and networksLeadership and trust
◦ Supportive structuresFormal and informal arrangements to share
Need to invest in this◦ Motivated individuals in informal networks have
been the backbone of successVulnerable system!
◦ One Health needs these organizational issues cared for
Otherwise, will only be a project with multiple players
How to do One Health◦ Lots of science questions today
Sound (veterinary) public health issuesMethods for risk detection and reduction
◦ A One Health program will be more than the scienceCollaboration across spheres of influence and domains of impact (good jargon eh)
Conflicting values, inadequate science◦ No clear easy decisions for best practices
Need a collaborative, horizontally managed program that allows for◦ Adaptation◦ Evaluation◦ Weighing the full suite of enablers and obstacles for
acceptable, feasible actions
http://www.clubofrome.at/events/2007/future/malaska.html
Risk assessment◦ Endemic known stuff in known exposure routes =
routineEx. Salmonella in eggs
◦ Emerging issuesHard to get public health attention without known agent and/or proven exposureLack data to measure and balance risks and benefits
Animals at critical control points (risk management)◦ Limits to public health authority to influence animal
careBut point of care = best opportunity for primary prevention
◦ Limits of veterinary community to be engaged in (re: paid for) primary public health prevention without obvious owner benefits
But, general animal care and robust animals are low risk
Survey in BC◦ If it ain’t rabies I don’t call
Not an effective way to achieve cooperative risk assessment and management
Chickens show us the need for team-based assessment and management
It is simply good public health practice
