Download Can Animal Sentinels Link Ecosystem and Human Health?

Can Animal Sentinels Link
Ecosystem and Human
Health?
Peter Rabinowitz MD MPH
Yale University School of
Medicine
Challenges in Human
Environmental Health
 Clinical

Encounters
Often hard to tease our environmental factors
from other more “medical” risk factors.
 Environmental

Health Tracking Initiatives:
Difficulty correlating human health outcomes
(asthma, cancer, etc.) with environmental
variables
The Problem:
Linking Environmental Health and
Human Health
 Mobility
of Human populations
 Exposures low level
 Long latency periods for some exposures
Can Animal Sentinels Be the
Missing Link?
Potential Advantages of
Animal Sentinels
 Animals
may be more susceptible than
humans to particular hazards
 Animals may be more exposed than
humans to environmental hazards
 Shorter latency due to short lifespan,
intergenerational period to see effects of
chronic exposures
Traditional Human Health
Perspective on (Non-lab) Animals
 Do
animals pose direct threat to human
health? (“Us vs. Them”)

Infectious agents
• Rabies
• Plague, etc.

Toxic agents (food animals)
• Mercury, PCBs in fish, etc.
Traditional Response:
“Blame the Animal”
 Avoidance



Quarantine
Education
Personal protection
 Vector/reservoir
population control
 Vaccines and drugs
Animals Sentinels and
“Shared Risk”

Is infection or toxin in
an animal a “sentinel
event” warning of a
shared risk from
environmental
hazards?
 A conceptual leap
from “Us vs. Them”
“Shared Risk” Model
 Communication
between animal and
human health clinicians
 Early recognition of hazards
 Enhanced prevention and treatment
 Growing body of knowledge linking animal
and human health
“Shared Risk” Example:
Asthma

Human prevalence increasing
 Attributed to multiple environmental factors,
including respiratory irritants, mold and other
allergens, inadequate , air quality
 Still difficult to correlate asthma rates with
particular environmental variables, indoor vs.
outdoor exposures play a role

Could animals serve as asthma sentinels?
Who Stays in the House All Day?
Case of Shared Risk
for Asthma
 Asthma
is diagnosed in cat
 Testing of cat reveals reactions to several
allergens and irritants in the environment
 Steps are taken to improve conditions that
help both cat and humans
 Vet and MD talk
 Family’s physician is is able to detect early
asthma in teenager living in house
Why We Are Not There Yet

We don’t know much (anything?) about:





How does cat asthma differ from human asthma?
Are cats more susceptible than humans to particular
asthma triggers?
Do cats have higher exposures to particular
allergens?
Does asthma develop sooner in cats than humans
Are there cases of cat asthma providing early warning
for humans?
Example: Avian Influenza
Shared Risk Ideal for AI
 Reports
of AI infection in animals leads to
quick interventions to reduce human
exposure risk
 We reliably track animal cases of
emerging AI
 And we use the animal data to better
understand the environmental risk factors
for both animal AND human infection
Why We’re Not There Yet





Linkage between human cases and poultry
exposure poorly understood- no evidence of
wildlife-human transmission of HP H5N1
We are still learning about environmental risk
factors for spread and propagation
We don’t know about relative exposure risks of
animals and humans or relative susceptibility
Roles of companion animals poorly understood
So the human health implications of AI being
detected in an animal remains uncertain
Animal Sentinel Evidence Linking
Human and Ecosystem Health
“Sentinel Science”
(Evidence)
Human/animal
Comparative
Biology
Host Factors
“Medical”
*Latency
Genomics
*Susceptibility
*Exposure
Clinical Reports
Exposure Studies
“Us vs.
Them”
Epidemiology
*Climate
Environmental
*Urbanization
Factors
*Vector ecology
“Ecology”
*Land use
Disease models
“SharedRisk”
The Canary Database:
Animals as Sentinels of Human
Environmental Health Hazards
 (http://canarydatabase.org)
 An
interdisciplinary project
funded by the National
Library of Medicine
Canary Data
 Assembles
studies of animals as sentinels
 Highlights evidence providing linkages to
human health
 Data summaries
 Identifies evidence gaps

The project is searching the scientific literature
for evidence that various animal species could
fulfill any of the following “sentinel” criteria:





Increased Susceptibility
Higher Exposure
Shorter Latency
Evidence of providing early warning for humans
Role of environmental factors
Use of Canary Data
 Veterinarian
is seeing cat with asthma
 Checks Canary database, sees that cats
are more likely than humans to react to -- Is able to use this info to screen for
reaction
 Is able to use info to discuss with
physician
Use of Canary Data (cont.)
 Public
health department is seeing
mortality of birds
 Checks Canary database for ways to link
to human health- including environmental
variables (and human factors) associated
with human risk from a zoonotic outbreak
 Able to prioritize and carry out
interventions BEFORE human cases
Thanks To:

USGS National Wildlife Health
Center


Yale Center for Medical
Informatics



Matthew Wilcox
Yale Occupational and
Environmental Medicine
Program


Prakash Nakdarni
Dan Chudnov
Yale School of Public Health


F. Joshua Dein
Lynda Odofin, Zimra Gordon,
Ann Liu, Vivian Lee
National Library of Medicine