One Health to address
future crises
The entire world is facing complex challenges linked to the
rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2),
which causes coronavirus disease COVID-19. Epidemiologists and virologists are
in the first line in understanding where the virus originated, how it adapted
to a new host (humans) and how it spreads. Even if to date there is still
uncertainty about the exact source, currently available evidence identifies
horseshoe bats (Rhinolophus affinis) and pangolins as intermediate host that
might have facilitated transfer to humans (1) in Wuhan region, followed by a
rapid spread across China, Europe and the rest of the world. The possibility that new viruses emerge from wild or
domestic animals, is well known (e.g. viruses of HIV, H5N1 highly pathogenic
avian influenza, H1N1 swine flu, Ebola, Middle East Respiratory Syndrome, etc).
The first severe acute respiratory syndrome (SARS) epidemic in 2002 showed us
the devastating impact coronaviruses can have in term of economic disruptions
to affected countries, mortality rate, and possibility of re-emergence (2).
Animal, human and environmental health: everything is
interconnected
Diseases that are transmitted between animals and humans,
called zoonotic diseases, are becoming more and more frequent as the distance
between people and wildlife is shrinking and contacts becoming more frequent,
as human populations encroach on natural areas. The increasing demand for raw
materials and resources such as wood, minerals, fuel and crop land mainly for
producing livestock feed, is leading to a widespread degradation of ecosystems
and causing ecological disruption. There are many challenges in relation to our
models of agricultural production, esp. in the Global North, in relation to
loss of biodiversity, soil and water contamination and emission of greenhouse
gasses. We need to look at these models and ask ourselves how they fit into a
changing world in light of climate change and global pandemics. We also need,
as a society, to ask ourselves what we are willing to pay for our food if we
change these models and if we are prepared to give farmers the economic incentives
to change their systems. Intensification is also increasing the risk of
transmission of diseases due to the proximity of large numbers of animals in
restricted spaces. Deforestation driven by logging, mining, road building, and
rapid urbanization leads to the disruption of habitat that pushes wildlife to
move and mix with other animal species and with humans, increasing the risk of
zoonotic pathogens’ spread (3). All these changes are happening at unnatural speed and
contribute to shorten the distances and increase contact between people,
wildlife and possible disease reservoirs.
One Health key to address complex health crisis
The COVID-19 pandemic emphasises once more that human health
and animal health are interdependent and bound to the health of the ecosystems
in which they exist. This interconnection between the health and well-being of
people, animals and the environment is known as One Health. One Health as a
concept was developed (4) to respond to the spread of serious infectious
diseases and zoonoses through an integrated approach to health. After many
failures in properly addressing complex health crises, it became clear that
collaboration between different sectors – involving researchers, laboratories,
public services and civil society – is fundamental to tackle disease spread
from all possible angles and create a solid basis for disease control.
Despite some efforts in making One Health operational,
disease surveillance and response systems often remain siloed between the
human, veterinary and environmental scientific communities. If collaborations
are effectively put in place, we would be better prepared in responding quickly
and effectively to new diseases. Veterinarians and ecologists, for instance,
have a central role in identifying disease reservoirs both in wild and domestic
animals.
In the global South, these collaborations are key to
optimise the few resources available and to strengthen public health. The fact
that in Africa and South East Asia more than 241 million people fall ill and
312,000 die each year for food-borne diseases (5) (many of them directly linked
to consumption of contaminated animal-sourced food or water) shows clearly that
there is no health and food security without food safety and hygiene. In
solving this simple equation, joint efforts from different sectors are
required: human medicine; veterinarians; microbiologists; experts in water,
sanitation and hygiene; sociologists; gender specialists, economists, etc.
In order to limit the spread of COVID-19, it is central to
understand that each local context is unique from a socio-cultural perspective
but also in terms of available infrastructures or housing conditions. Millions
of people lack access to running water (44% of African urban populations lack
access to piped water (6) and the percentage increases dramatically in rural
areas). People without access to water will struggle to enact the basic hygiene
recommendations – such as washing hands – that are repeated again and again by
medical authorities during this COVID-19 crisis. Social distancing is also
difficult to perform where entire communities base their livelihood on the
informal economy and live in confined spaces.
Adapted solutions and messages should be developed in order
to maximise populations’ capacity to adopt them and effectively limit the
propagation of the virus. The role of NGOs, local civil society and community
leaders that know local contexts well is fundamental to develop adapted
prevention strategies in areas that are poorly served by public services.
Again, all this should be done under a One Health collaborative approach.
A paradigm shift
In the current situation, One Health proves to be important
not only as a response to a specific health crisis, but as a way to rethink the
foundation of our societies and production systems. Examining how human, animal
and environmental health systems can work together is clearly an important part
of learning from the current crisis in order to build our resilience throughout
this pandemic and as we prepare for other threats such as future pandemics and
climate change related threats.
The global situation caused by COVID-19 is more than a
public health emergency. It is a political, economic and social crisis that
will have long-term impacts on the economic well-being of people, on their
habits and on the role of politicians in managing complex global emergencies.
In finding ways out of this crisis, we urge a deep questioning of our global
models of production, consumption and trade; of local and international
markets, of agriculture and livestock production.
Sustainable agricultural practices such as agro-ecology can
help to re-establish ecosystem balance by producing healthy food in an
environmentally sound way, protecting biodiversity, promoting fair and
sustainable marketing channels, supporting local food systems, and respecting
animal welfare, all contributing to the wellbeing of humans, other living
beings, and entire ecosystems.
In the midst of confinement measures, limitation of
movements and international transport, local food systems are proving to be
much more resilient than industrial agriculture, whose complex value chain is
fragmented and dependant on international trade (7). Local food systems,
small-scale farming and agro-ecological practices should be strongly supported
worldwide. Globally, small-scale farmers provide 70% of the food in the
markets, forming a pillar of food security, while preserving natural areas and
biodiversity through sustainable agricultural and livestock practices
integrated in natural processes.
If we want to be better prepared to face new diseases, we
need to embrace One Health in all its nuances: by putting in place
collaborations between the human, veterinary, and environmental communities, by
strengthening public health, but also by changing drastically the way our societies
and economies relate to nature, starting with supporting local food systems,
small-scale farmers and agro-ecological production methods.
(1) Lam, T.T., Shum, M.H., Zhu, H. et al. Identifying
SARS-CoV-2 related coronaviruses in Malayan pangolins. Nature (2020). https://doi.org/10.1038/s41586-020-2169-
(2) Vincent C. C. Cheng, Susanna K. P. Lau, Patrick C. Y.
Woo, Kwok Yung Yuen (2007) Severe Acute Respiratory Syndrome Coronavirus as an
Agent of Emerging and Re-emerging Infection. Clinical Microbiology Reviews Oct
2007, 20 (4) 660-694; DOI: 10.1128/CMR.00023-07
