Download Highly Pathogenic Avian Influenza

Bush Meat & Zoonotic Disease
Proactive Solutions for a Dynamic
Environment
College of African Wildlife Management
Mweka, Tanzania
July 2008
Overview
• Bush Meat and Zoonotic Disease
– The Link
– Global Viral Forecasting Initiative
– Solutions
• Disease Prevention & Response
– Monitoring & Surveillance
– Diagnosis
– Response
Bush Meat and Zoonotic Disease
• The problem… from a public health
perspective:
– Wildlife populations frequently harbor, often
silently, zoonotic disease pathogens
– Bush meat hunting places people in intimate
contact with wildlife blood/tissues and increases
risks of disease transmission
Livestock and Zoonotic Disease
• Livestock may serve as
intermediaries of zoonotic
disease transmission
between wildlife and
humans
– Cases of Avian Influenza
and Nipah virus
• Livestock holders at-risk
for zoonoses
Bush Meat and Zoonotic Disease
• Zoonoses that have
jumped from wildlife
reservoirs to humans
through bush meat
hunting/consumption
in Africa
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HIV
Ebola Virus
Marburg Virus
Monkeypox Virus
Simian Foamy Virus
Wolfe, ND. Et al. Emerging Infectious Diseases. Vol. 11. No. 12. December 2005; 1822 - 27.
Bush Meat Consumption
• In Cameroon:
– new timber concessions
– new roads to access the resources
– increased demand for animal protein
Increased
Bush Meat
Consumption
• Across income classes in Cameroon, ~ 9% of meat
budget is spent on bush meat (International Institute of Tropical Agriculture)
• Western Serengeti, Tanzania:
– Bush meat comprised 55-95% of meat protein
requirements (Barnett, R. TRAFFIC East/Southern Africa. 2000)
Bush Meat Consumption
• Congo Basin:
§ Bush meat consumption estimated at >282
g/person/day; annual extraction > 4.5 million tons
(Fa JE, et. al. Conservation Biology 2002:16: 232-7)
• Central Africa Overall:
§ Estimate: ~ 579 million animals off-take as bush
meat
(Fa JE, et. al. In: Conservation of Exploited Species. Cambridge University Press. 2003 203-241)
Bush Meat: The Broader Context
• Biodiversity
Bush
Meat
Issue
• Conservation Efforts
• Economy
• Global Public Health
Bush Meat and Zoonotic Disease
Transmission
•
Risk Factors:
1) Pathogen Prevalence
2) Human and Wildlife
Interaction via
hunting, slaughtering
and butchering
3) Environmental
Change that facilitates
human/wildlife
interaction
4) Human Behavior
A.Asamoah/GWS
Bush Meat and Zoonotic Disease
Transmission
• Pathogen Prevalence
– Pool of available, circulating pathogens
– Propensity for pathogen sustainability within
wildlife populations (animal to animal)
– Pathogen affinity for human host
• RNA viruses
• High mutation and recombination rates
Bush Meat and Zoonotic Disease
Transmission
• Human and Wildlife Interaction
– Highest risks associated with hunting
nonhuman primates, particularly
chimpanzees
– Risks increase associated with level of
contact:
• Opening the Carcass
(Butchering/Dressing)
• Preparing and Cooking Meats
• Transport
• Sale
UWSC
Bush Meat and Zoonotic Disease
Transmission
• Environmental
Change
– Climate change
– Natural resource
extraction
– Agricultural
encroachment
– Loss of habitat
Human and Animal
Population
Dynamic Shifts
Bush Meat and Zoonotic Disease
Transmission
• Human Behavior
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Human Migration
Population Growth
Protein Poor Diets
Social and Cultural
Practices (traditional
medicines)
– Wildlife/Exotic Animal
Trade
A.Asamoah/GWS
Bush Meat and Zoonotic Disease
Transmission
• Global Viral Forecasting Initiative
• Pilot project of Dr. Nathan Wolfe (UCLA/UCSF)
• Goal: forecast potential viral outbreaks before they reach
epidemic status (e.g. HIV)
• Working collaboratively with hunters to identify previously
unknown viruses
– Animal blood samples (hunter-collected) screened for unknown viral
gene sequences
– Create data bank of animal viruses
Global Viral Forecasting
Initiative
• Screening at-risk populations (hunters, market
vendors) for viral antibodies as sentinel of virus
exposure
– Simian Foamy Virus found in Cameroonian hunters;
however no human-human transmission to date
• Matching idiopathic human illness with possible
viral etiologies
Global Viral Forecasting
Initiative
• “Viral Chatter”
– Continual low-level interchange of genetic information amongst
viral subtypes
• Recombined viruses may acquire novel properties (humanhuman transmission) that make them particularly
dangerous
• Monitoring “viral chatter” and early identification of
outbreak potential
Global Viral Forecasting
Initiative
• Overarching themes:
– Where is the next infectious disease pandemic likely to
originate?
• What does the data tell us about global “hot spots” of emerging
infectious disease: where should we concentrate our resources?
– How might we expect it to behave?
– Can we mobilize resources in advance to be proactive
rather than reactive in our response?
• Link viral characteristics (e.g. surface proteins) with pandemic
potential
• Establish disease surveillance systems focused at these “hot
spots” that target the human/animal interface
Bush Meat and Disease
Transmission
• How can we limit
 Decrease host density
opportunities for
(people and livestock)
infectious disease
available to the pool of
transmission at the
circulating pathogens
human/wildlife interface?
 Equip and protect
populations at highest
risk of exposure to
pathogens
Bush Meat and Disease
Transmission
• Decreasing host density available to
pathogens
– Low impact natural resource extraction (e.g.
logging) that seeks to limit human/wildlife
interaction
– Limiting new road construction into wildlife
habitat
• Roads increase range of existing hunting areas
and open new areas to hunting
– Promote sustainable agricultural practices that meet
nutritional demands and improve livelihoods
• High yield crops
• Irrigated agriculture where appropriate
• Discourage clearing of new lands, particularly
fringe areas and park boundaries
ZSL
Bush Meat and Disease
Transmission
• Equip and protect
populations at risk of
exposure:
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Education
Training
Awareness Campaigns
Personal Protective
Equipment
• Target At-Risk Populations:
– Hunters
– Market Vendors/ Middlemen
– Park Rangers & Wildlife
Officials
– Timber Workers
– Veterinarians/Animal Health
Workers
Bush Meat and Disease
Transmission
• Keys to success:
– Education
• Including schoolchildren
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Training/Outreach/Awareness
Enforcement
Adequate Nutrition
Alternative Livelihoods
A.Asamoah/GWS
Best Policy:
Avoid Contact
with Wildlife
N.Wolfe
N.Wolfe
Bush Meat and Disease:
Education and Awareness
• Messages must be carefully crafted and focused:
– Reality of health risks as means of deterring bush meat
hunting
– Consideration of costs associated with bush meat
hunting
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•
•
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Medical and transportation costs to treat illness
loss of income/productivity due to illness or death
cultural ostracism
fines/legal action
– Active hunting will not control disease prevalence
Bush Meat and Disease:
Education and Awareness
• Provide information
that will limit disease
transmission
opportunities
UWSC
• Hunters should:
– Avoid visibly sick animals
– Use personal protective
equipment (gloves, masks,
etc…)
– Avoid high risk butchering
practices
– Seek medical help
immediately upon signs of
illness
Bush Meat and Disease:
Education and Awareness
• Locations for Outreach:
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Bush Meat Markets
Urban Markets
Livestock Markets
Stops Along Trade and
Transport Routes
Schools
Government Offices
Veterinarians
Hospitals
• Campaigns Must:
– Have Good Penetration
to Target Audience
– Be Easily Understood
– Be Able to Respond to
Community Needs
– Be Culturally Sensitive
– Flexible and Adaptable
Based Upon Feedback
Bush Meat and Refugee Camps
• Camps may be in environmentally sensitive areas,
predisposing to bush meat hunting (Kagera &
Kigoma camps, Tanzania)
• Bush meat viewed as:
– Source of cheap, often preferred, protein
– Source of income for populations stressed & limited by displacement
• Refugee camp populations at higher risk:
– Inadequate nutrition/Protein poor diets
– Higher rates of illness and poverty
– High host density = rapid pathogen transmission
Bush Meat and Refugee Camps
• Solutions:
– Improving placement of refugee camps
• Future camps should avoid wildlife migration routes
– Ensuring nutritional/protein requirements of
populations are met
• Subsidized livestock based meats and eggs
– Better wildlife management practices in bordering
parks and game reserves
– Providing livelihood solutions
• Agricultural trainings and inputs
• Increased emphasis on self-reliance
Addressing Disease Emergence
Prevention and Response Solutions
• Monitoring & Surveillance
• Diagnosis
• Response
Disease Monitoring &
Surveillance
• Surveillance:
– The collection, analysis and interpretation of
data to confirm disease presence, identify
trends, and guide actions to control disease
• Community Based Disease Surveillance
– Utilizes trained community members to detect
and report cases using standard diagnostic
criteria
Community-Based Disease
Surveillance
• Allows surveillance under conditions of poor
infrastructure, large coverage areas, and
inadequate veterinary resources
• Contributes to disease database compilation
• Provides feedback to local community on disease
trends, risks, outbreak prevention strategies
• May be extended to include vaccination/treatment
delivery by local community members
Community-Based Disease
Surveillance
• Strengths:
– Improves diagnostic sensitivity
– Allows real-time ongoing monitoring with minimal
resources at minimal cost
– Fosters community education and awareness
• Weaknesses:
– High error rate: requires clearly defined case definitions
– First stage in outbreak detection: laboratory or health
worker confirmation needed
– Requires good communication/chain-of-command
CAHWs & Community-Based
Disease Surveillance
• Community-Based
Animal Health
Workers (CAHWs)
– Community members
trained in the
prevention and
treatment of common
livestock illness and
able to deliver services
at the local level
Practical Action
CAHWs & Community-Based
Disease Surveillance
• CAHWs may assist with community-based
disease surveillance by:
– Filling out regular disease monitoring forms
– Reporting suspicious/suspect cases to
veterinary authorities
– Identifying disease outbreaks at earliest stages
– Engaging in preventative activities (i.e.
vaccination)
Allport, R. Et. Al. Rev. sci. tech. Offic. Int. Epiz 2005. 24. (3); 921-932
CAHWs
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CAHWs generally bring an existing level of
indigenous animal health and husbandry
knowledge
Added benefits beyond disease surveillance:
Higher Meat/Milk Yields =
Improved Food Security
Improved Livestock
Health
Economic Self-Sufficiency
Improved Nutrition &
Human Health
Decreased pressure on
wildlife/bush meat
Diagnostic Capacity
• Equipment
– Infrastructure (i.e. generators, access to wells)
– Basic Laboratory Diagnostic Equipment
(microscopes, slides, incubators, reagents)
– Diagnostic Assay Kits
– Personal Protective Equipment/Biosafety Equip.
• Training
– Principles of Epidemiology
– Equipment and Assay Use
Building Laboratory Diagnostic
Capacity
… and Outbreak Response
• Epidemiology and
data analysis
training
• Rapid deployment
to address disease
outbreak incidents
Additional Resources
• World Organization for Animal Health
(OIE) www.oie.int
• One World, One Health
www.oneworldonehealth.org
• Bush Meat Crisis Task Force
www.bushmeat.org