Transcript The Impacts of Climate Change on Infectious

Emerging Diseases in a changing
European eNvironment
Jean-François Guégan
on behalf of the Steering Committee
EDEN
The Impacts of Climate Change on Infectious Diseases, December 14-15, 2009,
French Embassy, Washington D.C.
EC IP EDEN’ Call text
• The aim is to identify, evaluate and catalogue
European ecosystems and environmental
conditions linked to global change, which can
influence the spatial and temporal distribution
and dynamics of pathogenic agents and their
hosts
• A coordinated European approach is needed to
provide predictive emergence and spread
models including global and regional prevention,
early warning, surveillance, and monitoring tools
and scenarios
• Coordination with international organizations
and third world countries is essential
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EDEN general presentation
EDEN integrated project
• 24 countries,
• 49 partners,
• 80 scientific
teams,
• 120 field sites,
• 60 PhD students,
• 200 research years
• 12.8 millions euros
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EDEN general presentation
EDEN integrated project
49
24
Africa
WNV-RVF
Malaria
West
Nile
Leishmania
- grouped under WP6 -
Rodent
Borne
Horizontal Integration Teams
Tick
Borne
Vertical Disease Sub-Projects
Data Management &
Information Systems (WP6.1)
Low Resolution Remote Sensing &
Spatial Modelling (WP6.2)
High Resolution Remote Sensing &
Environmental Change Monitoring (WP6.2)
Mathematical Modelling &
Disease Establishment and Spread (WP6.3)
For each indicator disease, field studies
are conducted to understand
patterns and processes:
WP1 – Landscapes/biotopes
WP2 – Vectors
WP3 – Public health
WP4 – Animal hosts/reservoirs
WP5 – Integrated data analysis
Tools and
Scenarios
- WP7 -
Biodiversity &
Impact on Disease Spread (WP6.3)
WP8 Training, Dissemination, Management & Coordination
EDEN general presentation
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EDEN major field sites
120+ field sites,
170+ publications,
3 websites:
EDEN
DMT (2-3K hits/mon
PhD (2-3K hits/day)
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EDEN general presentation
EDEN website
www.eden-fp6project.net/
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EDEN general presentation
Impact of climate and other changes
Tick bioecology and tick-borne encephalitis
Coordinator: Dr. S. Randolph, Oxford
Ixodes demographic traits
• Temperature
Metabolic rate
Mortality rate
Life cycle duration
Population size
Blood-feeding rate
Distribution and survival rates
• Humidity: dehydration and survival
rates
• Precipitation
Presence / absence
Size and duration of breeding sites
Tick-virus interaction
• Virus replication
No replication below a temperature
threshold
Replication rates increase with
temperature
• Reduced efficacy within vector
barriers
Infection of gut cells
Leaky" gut: viruses pass directly in
haemocoel
Infection of salivary glands
Increased proportion of vector
population able to transmit
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EDEN general presentation
Impact of climate and other changes
Tick bioecology and tick-borne encephalitis
Coordinator: Dr. S. Randolph, Oxford
• Changes on vector and / or host
habitats
Changes in tick distribution in northern and central
Sweden. White dots: districts where ticks were found
Shift caused by climate change:
ticks encountered at higher
altitudes and expanding habitat
northwards,. . .
Gray et al., 2009. Effects of climate change on ticks and tickborne diseases in Europe. Interdisciplinary Perspectives
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on Infectious Diseases, doi:10.1155/2009/593232
EDEN general presentation
Impact of climate and other changes
Tick bioecology and tick-borne encephalitis
Coordinator: Dr. S. Randolph, Oxford
• Changes on vector and / or host
habitats
Annual TBE incidence per 100,000 population in each county
of Estonia, Latvia and Lithuania, 1970-2004
Shift caused by climate change:
ticks encountered at higher
altitudes and expanding habitat
northwards,. . .
. . . But also changes in land
cover and land use, possibly
caused by human activity.
• Factors affecting contact and
disease transmission between
vector and humans
Socio-economic changes
EDEN general presentation
Sumilo D, Asokliene L, Bormane A, Vasilenko V, Golovljova I and
Randolph SE, 2007. PLoS ONE,
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doi:10.1371/journal.pone.0000500 2: e500.
Impact of climate and other changes
Tick bioecology and tick-borne encephalitis
Coordinator: Dr. S. Randolph, Oxford
• Changes on vector and / or host
habitats
Shift caused by climate change:
ticks encountered at higher
altitudes and expanding habitat
northwards,. . .
. . . But also changes in land
cover and land use, possibly
caused by human activity.
• Factors affecting contact and
disease transmission between
vector and humans
Socio-economic changes
Occupational / recreational activities
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EDEN general presentation
EDEN findings TBE (1/4)
From a Pan-European analysis it was concluded
that observed patterns of climate change may
be too similar within and between countries to
provide the sole explanation for the extreme
spatio-temporal heterogeneity of the marked
upsurges in TBE incidence over the past two
decades (Sumilo et al. 2007; Randolph, 2008).
A nexus of interacting factors affecting both the
risk of infection and exposure of humans to that
risk, and each differing in force in space and
time, may provide a more powerful model.
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EDEN general presentation
EDEN findings TBE (2/4)
Extensive field studies and analyses conducted in an area of
endemic TBE in northern Italy have confirmed the effect of a
climatic indicator - the autumnal cooling rate – on TBE
transmission to domestic goats (Rizzoli et al., 2007).
The underlying bio-ecological mechanism is complex, with an
interaction between autumnal, cold-induced diapause in
immature tick stages, and co-feeding of immature and adult
ticks on vertebrate hosts at the beginning of the next activity
period.
Substantial changes in vegetation structure (that improve
habitat suitability for the main TBE reservoir hosts: small
mammals), as well as an increase in roe deer abundance due
to changes in land and wildlife management practices, are
likely to be among the most crucial factors affecting the
circulation potential of TBE virus and, consequently, the risk of
TBE emergence in humans in Europe (Rizzoli et al., 2009).
EDEN general presentation
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EDEN findings TBE (3/4)
Conceptual model and empirical evidence of causes of
spatio-temporal heterogeneity in TBE epidemiology
in Central and Eastern Europe.
Sumilo D, Asokliene L, Bormane A, Vasilenko V, Golovljova I, Randolph S 2007. PloS ONE, 2: e500
EDEN general presentation
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EDEN findings in a nutshell
A key outcome of EDEN is that many of currently
observed changes in disease occurrence are
driven by complex multifactorial causes and can
often not simply be linked to a single cause, e.g.
climate change.
Socio-economic factors affecting behavior and
contacts between hosts, vectors and pathogens
often appear to be more important drivers of
change than climatic factors.
This complexity should not be overlooked in
disease risk studies and public health policy
making.
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EDEN general presentation
EDEN International Conference
Thank you for your attention. . .
and welcome to the
International EDEN conference
on emerging, vector-borne
diseases in a changing
European environment
Montpellier 10-12 May, 2010
The Impacts of Climate Change on Infectious
Diseases, December 14-15, 2009,
French Embassy, Washington D.C.
Thanks to:
• Jacques Drucker, Agathe Dumas,
Delphine Tessier, Marc Magaud and
the French Embassy’ staff for
inviting me to participe to this
workshop
• IRD-CNRS-UM1-UM2, and EHESP
• EDEN IP GOCE-CT-2003-010284
and European Community
… for funding support
E-mail: [email protected]
Come to Montpellier
and visit us!
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EDEN general presentation