Last month, we joined the Democratic Republic of the Congo in celebrating a remarkable achievement — the end of an Ebola outbreak that had caused thousands of deaths and tremendous suffering in the country’s east. But sadly, the country could not afford to pause for a breather — a few weeks earlier, a separate Ebola outbreak had been reported in the country’s Équateur Province.
Six months into it, the world is still reeling from the impact of the Covid-19 pandemic. Like the recent Ebola outbreaks, this novel coronavirus has brought into sharp focus the dangers posed by a class of diseases called zoonoses — those which jump between animal and human populations.
Covid-19 is the latest — and one of the most devastating — zoonotic diseases to affect us in generations, but it is far from the first. Ebola, SARS, MERS, HIV, Lyme disease, Rift Valley fever and Lassa fever, to name a few, are all examples of zoonotic diseases. Today, 60% of all infectious diseases in humans are zoonotic, as are 75% of all emerging infectious diseases. Most of these are transmitted by wild animals, but others enter human populations through livestock. MERS, for example, was transmitted to humans through camels.
While today’s immediate priority is saving lives and incomes, we must also look at the conditions that have allowed zoonotic diseases such as Covid-19 to become more prevalent — and importantly, identify how to prevent future outbreaks.
In the past one hundred years, the human population has increased almost four-fold and the world has witnessed an unprecedented decline in the natural environment. From unsustainable agricultural intensification and our increased use and exploitation of wildlife to our infrastructure choices and unsustainable energy production and consumption, we have failed to nurture the planet on which our very lives depend. And that has triggered a rise in the emergence and spread of new zoonoses.
In a scientific assessment released this week, the United Nations Environment Programme (UNEP) and the International Livestock Research Institute (ILRI) argue that to prevent the next pandemic, countries must urgently integrate human, animal and environment health expertise and policy — a one-health approach to protect us and protect the planet.
One health is not a new concept, but its uptake and institutional support is uneven. Specifically, our assessment finds that the weakest link in the chain today is environmental health, despite a growing understanding of the links between our habitat and human health. Conservation experts monitoring great apes, for instance, can be a valuable part of zoonotic disease surveillance in communities living in proximity to them.
Experts monitoring habitats — and their destruction — also have a role to play, because we know that forest fragmentation has an influence on the emergence and spread of zoonoses. These experts should be working with livestock keepers, veterinarians and other environmental specialists to limit the spread of zoonotic diseases by jointly managing spaces where livestock and wildlife co-exist.
For example, in 2018, livestock experts working closely with human healthcare professionals in Kenya detected the emergence of Rift Valley fever and deployed livestock vaccinations and other interventions to contain its spread.
As we look at recovery from the current pandemic and the investments required to avoid another global catastrophe, one-health strategies should be front and centre.
Countries in Africa and others around the world that have managed deadly zoonotic disease outbreaks have much to offer. They have developed public health measures — from education campaigns to monitoring and contact tracing by local health centres — to protect members of the public when these outbreaks do happen. It’s no accident that the nearly two-year-long Ebola outbreak in eastern Congo did not lead to large-scale outbreaks in neighbouring countries.
Through experience, many African countries have improved their response to zoonotic outbreaks, something that has so far borne fruit as they address Covid-19, with countries locking down and instituting physical distancing early on in the pandemic. Others quickly made health-related economic adjustments such as moving to mobile money to curb the risk of disease transmission through cash transactions.
With the world more interconnected than ever before, we have the opportunity to mix the wisdom of experience with the promise of innovation for solutions that can address the complex human, animal and planetary problems that brought us Covid-19.
Today, the chain reaction from a sick planet to sick animals and humans is clearer than ever. Preventing the next pandemic will require protecting the health of the planet and all who inhabit it.
Inger Andersen is the executive director of the UNEP and Jimmy Smith is the director general of the ILRI