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Sentinels
Organisms whose known characteristics can be measured to access the extent of environmental implications... and to provide early warning of thse implications.
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Examples of animals as sentinels
- Lyme disease in North America (fleas)
- Minamata disease (dancing cats)
- Canaries in the mines
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Lyme Disease
- Borrelia burgdorderi
- Vector is Ixodes ticks (not common in AB)
- Primary hosts: mice, squirrels, other mammals, small birds, ... Migratory birds?
- TIck infected by biting rodent, then later bites larger animal...
- Pathogen transmitted when tick's mouthparts are attached for 18-24 hours
- Spread from eastern US, not yet thought to be endemic in AB,
- Surveillance program in AB since 2007--> submit ticks to vets--> ab ag parasitology
- Several ticks submitted in AB in 2011 and 2012 were infected
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Symptoms 4 Lyme disease
- Humans: fever, headache, fatigue, swollen lymph nodes, arthritis
- Bulls-eye rash
- Dogs: fever, lethargy, shifting arthritis
- Diagnosis: blood testing (for antibodies)
- Treatment: antibiotics
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Minamata Disease
- In 1965, first patient suffering from nervous symptoms
- Patients were men and women, but not children, later children were born with it...
- First clue was cats are behaving in similar ways... (cat dancing disease)
- Staple food of residents and pets was seafood, thus fish- shellfish mediate food poisioning was first to become suspect
- Ending the contamination, cleanup and compensation of victims took many years
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Human Population Growth:
Its effects on Sentinels
- Loss or modification of habitat
- Predation (ecological changes affecting predators or prey)
- Introduction of non-native species
- Air and water quality impacts
- Climate changes
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Water Quality & Quantity Effects
- Herbicides
- Pesticides
- Heavy Metals
- Other materials in run-off
- Decreased pH & increased salinity
- Lowering of water table
- Loss of freshwater spring flows
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Air Quality Effects
- Greenhouse gas production
- Volatile organic compounds
- Aerosolized pesticides & other chemicals
- Particulate matter and silt/sedimentation
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Need to bridge the gap
Between ecologists and medicine
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Complementary Approach: Naturally Occuring Disease in Animal Populations
- Companion Animals
- Livestock
- Wildlife
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Descriptive epidemiology
Characterize the frequency and patterns of disease in animal populations and identify possible associations with environmental exposures
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Analytic epidemiology
Test hypotheses of environmental exposure-disease relationships in animals using controlled-observational methods
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In situ studies
- Placement of sentinel animals were environmental contamination is suspected
- Monitor the animals to assess health effecs.
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Ideal animal sentinel
Is exposed to chemical contaminants in habitats share with humans, or is comparable
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Optimize sentinels
- Animals can serve as valuable sentinels for hazards in the home, ONLY if they are recognized and reported in timely matter...
- This system requires cooperation between human and vet. health specialists
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