Climate Change and Ebola Outbreaks: Are they connected?

Abstract

The climate factors have an impact on pathogens (resistance, selection, etc), hosts (biology like immunity, ecology like migration movements, etc), vectors (ecological niches, vector capacity) and epidemiological dynamics. The climate can affect the rate of transmission, the way in which pathogens are dispersed, contact networks between individuals and between different species, community structures. Livestock farming methods, or biodiversity and its ambivalent role in disease emergence are also depending of climate factors. The diseases most sensitive to climate factors are parasitic diseases with external life-cycle, vector-borne diseases and infectious diseases passed on by water or micro-mammals including bats. Most of them are zoonosis.
For a zoonosis like Ebola, several potential drivers are suspected to connect climate change to ecosystems, virus transmission to Human and heath care policies:
1. Ecology and behaviour of the bat species suspected to be Ebola virus reservoir could be affected by climate change: population density, migration, habitat utilisation, reproduction, feeding behaviour, and nature or intensity of inter-specific contacts. All those parameters would have an impact on the ecology of the Ebola virus. Therefore, researches for understanding the mechanisms of virus maintenance, circulation and transmission and for identifying reservoir and bridge species need to address the correlations between Ebola foci and its environmental factors, including climatic factors.
2. Human contamination by Ebola virus can occur through close or direct contact while hunting or through eating meat from wildlife. Climate changes can for one side, favour contact between wildlife and humans by impacting the natural habitats of the reservoir species and by influencing their movements. For other side, climate evolution may also exacerbate food insecurity, which can in turn modify human behaviour, particularly by prompting people to look for alternative food sources, such as bushmeat.
3. Low-income countries must reinforce their health systems to detect earlier infectious zoonotic diseases and control outbreaks, by taking into consideration potential impact of climate change in their sanitary strategy and policy. Indeed, health systems are structurally inadequate in the least advanced countries, where they endure rather than anticipate climatic conditions and their variations. The recent Ebola epidemic in West Africa bears witness in particular to the need to step up the early detection and management of the emergence of zoonosis taking into account accurate environmental, social and climatic data.
Research and health management regarding these 3 items should be carried out through the “One Health” concept. This holistic approach includes both animal health and human health in their shared environment. The implementation of a multidisciplinary and intersectoral approach requires above all an awareness of its benefits and greater involvement of all the scientific and policy makers. The issue of climate change and its impacts on viral diseases may be an axis of reflection on this integrated approach, and Ebola disease is a topical issue.
Our poster presents some examples of North-South collaboration between teams which are fighting together against both climate change and Ebola crisis.

Full text

Climate Change and Ebola Outbreaks:
Are they connected?
Research and health management regarding these 3 items should be carried out through the “One Health” concept. This holistic approach includes both
animal and human in their shared environment. Thereby, the issue of climate change in relation with recent Ebola outbreaks especially and infectious
diseases in general, must be taken up in single framework by research teams.
D. Kassié (1) ; M. Bourgarel, (1) ; F. Roger (1)
(1) Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), Environnement et Sociétés (ES) / UR AGIRs - Animal et Gestion Intégrée des Risques, Montpellier, France
Daouda.kassie@cirad.fr
Climate change may affect
life history traits of bats
(suspected Ebola virus
reservoir) :
- population density,
migration, habitat utilization
Human contamination can occur through
contact while hunting or eating bushmeat.
The climate factors have an impact on pathogens, hosts, vectors and epidemiological dynamics :
-the climate can affect the rate of transmission, the way in which pathogens are dispersed, contact networks between individuals and between different species.
Livestock farming methods, or biodiversity and its ambivalent role in disease emergence are also depending of climate factors.
-the diseases most sensitive to climate factors are infectious diseases passed on by water or micro-mammals including bats. Most of them are zoonosis like Ebola.
EBOLA VIRUS CIRCULATION AND TRANSMISSION
Several potential drivers are suspected to connect climate change to ecosystems, virus transmission to Human and heath care policies :
- reservoir species (i.e. bats) and their contacts with other animal species
- low income countries health systems
- human activities (like logging and agriculture) worsen climate change impacts and increase contacts between animals and men.
Climate changes can favour
contact between wildlife and
humans by :
- impacting the natural
habitats of the reservoir
species
TO GO FURTHER
CONTEXT
Seasonal factors may
influence wildlife
distributions, potentially
increasing their contacts
with Ebola reservoirs. Thus,
Ebola virus may also infect a
number of animal species,
most notably nonhuman
primates mostly in the
highest areas of
transmission.
D. Cornelis/CIRAD
Low-income countries must :
- reinforce their health systems to detect earlier
Ebola cases and control outbreaks
- take into consideration potential impact of
climate change in the sanitary strategy and policy
Alexander and col., 2015
After D. Guard-Lavestre/CIRAD and CDC : http://www.cdc.gov/vhf/ebola/resources/virus-ecology.html
After Roger F. and Col. / CIRAD
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ECOLOGY AND BEHAVIOR OF BATS HEALTH SYSTEMS
HUMAN-ANIMAL INTERFACE
Funk and Piot, 2014
Highest areas of Ebola
emergence
A model of Ebola risk
transmission
french.peopledaily.com
- reproduction, feeding behavior, nature or
intensity of inter-specific contact
- modify human behavior and activities
(deepest incursions in forests)
Climate change may
exacerbate food
insecurity, which can
modify human behavior
by prompting more
people to look for
alternative food source
such as bushmeat.
CLIMATE CHANGE MAY IMPACT ENVIRONMENT, HUMAN
BEHAVIOR, HEALTH SYSTEMS AND EBOLA VIRUS
EPIDEMIOLOGICAL DYNAMIC
Gabonews