Whatever else about 2020’s pandemic and its devastating impact on lives and livelihoods, it was not unpredicted. A flu-like pandemic has been at or near the top of risk assessments by UK governments and the World Bank for years.
As recently as October 2019, only the US was judged to be better prepared for a biological threat to health – the UK was ranked second by the Global Health Security Index. Yet no country was fully prepared for a pandemic, and it warned: “political will for accelerating health security is caught in a perpetual cycle of panic and neglect”.
One question being asked is whether Covid-19 is zoonotic. That means to say, is Covid-19 an infection that is naturally transmissible from vertebrate animals to humans? Strictly speaking, because the virus has not, at the time of writing, been traced to an animal reservoir, some scientists argue that this classification is premature. Instead Covid-19 should be referred to as “an emerging infectious disease of probable animal origin”.
Download this whitepaper to gain a fascinating insight into the increasingly clear and present danger from zoonoses, laid bare by this pandemic.
Whatever else about 2020’s pandemic and its devastating impact on lives and livelihoods, it was not unpredicted. A flu-like pandemic has been at or near the top of risk assessments by UK governments and the World Bank for years.
As recently as October 2019, only the US was judged to be better prepared for a biological threat to health – the UK was ranked second by the Global Health Security Index.1 Yet no country was fully prepared for a pandemic, and it warned: “political will for accelerating health security is caught in a perpetual cycle of panic and neglect”.
The price of that unpreparedness has been writ large by Covid.
The known, the neglected and the unknowns
The 2020 edition of the UK’s National Risk Register observes that more than 30 new or newly recognised diseases have been identified over the last 30 years. Most have been zoonoses – zoonotic diseases and infections caused by pathogens (viruses, bacteria or parasites) transmitted from animals to humans.
Zoonotic diseases can be categorised in several ways.
Endemic zoonoses are ever-present in geographic populations. In the UK, Public Health England reported 35 endemic zoonoses in 2019. Lyme disease and toxoplasmosis are the best known, accounting for 1,630 and 350 reported cases that year.2
Many endemic zoonoses are termed ‘neglected’ by the UN. These persist across the globe, yet receive much less international attention and research funding than emerging zoonotic diseases. Examples spread by domestic animals include brucellosis, cysticercosis (pig tapeworm), Q fever and rabies, while Lassa fever has a wildlife host (the multi- mammate rat).
Epidemic zoonoses – such as anthrax and Rift Valley fever – tend to be intermittent and mostly, but not all, limited to areas of origin. They can be triggered by climate changes, flooding and other extreme weather events, and famines.
Emerging zoonoses appear for the first time in a population, or re-emerge with a vengeance, spreading rapidly. The Zika virus, for example, which caused a major epidemic in the Americas in 2015-16, was originally discovered in Uganda in 1947, and the first human cases were detected there and In Tanzania in 1952.3
While most emerging zoonoses are not lethal and do not spready widely, some result in explosive outbreaks and high fatalities. The pandemic influenza H1N1 killed between 50 and 100 million people worldwide in 1918-19. Other emerging zoonoses include avian flu H5N1, SARS (severe acute respiratory syndrome),4 and now (it seems – see box), Covid-19.
We expect the consequences of Covid to concentrate political and public health agencies’ attention on the threat from emerging zoonotic diseases. But is Covid actually a zoonosis? The World Health Organization (WHO) defines zoonosis as “any infection that is naturally transmissible from vertebrate animals to humans”.Strictly speaking, because the virus has not, at the time of writing, been traced to an animal reservoir, some scientists argue that this classification is premature. Instead Covid-19 should be referred to as “an emerging infectious disease of probable animal origin”.Swab samples collected from surfaces and cages in the Wuhan wet market did test positive for the virus. It has also been found in various animals from domestic cats to farmed mink, but no cases of natural transmission from wild or domesticated animals have been confirmed.
The growing danger and its drivers
SARS was a wake-up call for the global North, which seemed to have forgotten the great Spanish flu pandemic that coincided with The Great War. Spreading rapidly from Asia to Canada in 2003, the coronavirus infected more than 8,400 people and killed one in 10.6 Countries with more recent experience of such pandemics have generally been better prepared for Covid than Europe and the US.
This latest coronavirus pandemic has laid bare the clear and present danger from zoonoses – and it is rising.
Almost all known pandemics are caused by zoonoses and they are becoming more frequent. Long before Covid, just 13 zoonoses were found to be infecting 2.4 billion humans each year, causing an estimated 2.2 million deaths.7 Researchers estimate that six out of 10 diseases known to be infectious in humans are spread from animals. They are also the source of three out of four new or emerging infectious diseases in people.8
More than five new diseases are now emerging in people every year, any one of which has the potential to spread and become pandemic.9 For a century, the spill-over rate of viruses from animal hosts to humans was two a year.10 The frequency of such zoonotic disease outbreaks may have more than tripled in the last decade, and the diversity of these pathogens has also increased, with the number of new zoonotic diseases infecting people quadrupling over the same time period.11
Beyond the spectrum of known zoonoses – from anthrax to Zika – there are more than half a million undiscovered viruses out there. An estimated 1.7 million currently undiscovered viruses are thought to exist in mammal and avian hosts. Of these, it is estimated that 631,000-827,000 could have the ability to infect humans. The most important reservoirs of pathogens with this potential are mammals (in particular bats, rodents, primates) and some birds (especially water birds), as well as livestock (pigs, camels, poultry).
But it is humans, not animals, that are to blame.
Changes in land use, agricultural expansion and intensification, and the wildlife trade and consumption all lead to greater contact between humans and animals, and it is these paths that experts say have led to almost all pandemics.
Climate change is another factor; enabling tick-borne encephalitis to spread to Scandinavia, for example, or thawing permafrost to release anthrax spores in Siberia. The climate emergency will heighten the risk of future pandemics by driving the migration of people, wildlife, and insects that act as vectors for their diseases, as well as leading to new contacts between species.
Biodiversity loss contributes too as species are forced to move and adapt to landscapes where people live, and due to the ‘dilution effect’: there is growing evidence that rich biodiversity of species makes it harder for a single pathogen to dominate and thus, inhibits transmission. Losing unexplored species also deprives science of opportunities to discover natural treatments and cures for zoonotic and other diseases.
The untenable costs of containment
Current strategies for pandemic preparedness aim to control diseases after they emerge.
Historically, animal pathogens have spilt over into human populations in ‘remote’ areas of the world and undeveloped countries. This has facilitated the ‘panic or neglect’ mode decried by the global health lobby.
There are obvious flaws in the logic of containment. These health authorities often lack the surveillance and diagnostic capabilities, and other medical resources, to alert their neighbours and the world, let alone mobilise their own rapid and sufficient response. The 2014-16 Ebola epidemic in West Africa, after an initially slow response, was only brought under control with immense international support, coordinated by the World Health Organization (WHO), and sporadic outbreaks continue to occur.
Politically motivated obfuscation and delays in reporting can allow emerging diseases to spread unchecked across borders, and maverick leaders may undermine national control measures, as seen with Covid.
Scientists and pharmaceutical companies, with government support, heroically developed vaccines within a year of the latest coronavirus outbreak. The world might not be so lucky next time, and not all emerging zoonoses will attract such investment, to the detriment of some countries or regions.
Moreover, containment is untenable in today’s connected world. That reality was already clear before Covid. SARS quickly spread across the world to Canada from South-East Asia. MERS (Middle East respiratory syndrome), which appeared in 2012, affected a dozen countries across the region.17
Zoonoses are already exacting a heavy economic cost on many developing countries, and have been for decades.
The annual cost to India of the pig tapeworm is $150 million. Altogether, 50 million people around the world are affected, 80% of them in developing countries. At least 55,000 people die of rabies in Asia and Africa, while the UN puts the cost of prevention and control on these two continents at $590 million a year.18
According to the UN and World Economic Forum, $100 billion has been lost to zoonotic diseases over the past two decades, not accounting for COVID-19.19 The IMF estimates that lost economic output due to the pandemic will amount to $28 trillion by 2025.20
<h2id=”one”>The one health approach
The pandemic has given the world an extremely painful and financially ruinous lesson in the inadequacy of preparedness and reactive responses to controlling zoonotic diseases in the 21st century.
There is an alternative approach that has been advocated since the turn of the century. For two decades, global health experts have championed ‘One Health’ – a collaborative, multisectoral, and transdisciplinary approach to disease threats. Crucially, given the factors driving the emergence of zoonoses, One Health focuses on where the health of people, animals and the environment converge.
At a global level, there is broad support for the concept. Nearly 50 countries have signed on to the Global Health Security Agenda (GHSA). Endorsed by the G7 group of leading nations, it launched in 2014 to bring countries together to promote One Health approaches and strengthen capacities to prevent, detect, and respond to disease threats.
Several such initiatives have been established around the world, including within US federal agencies, Bangladesh and Liberia, as well as inter-agency working groups, and international alliances (such as those covering South Asia and Eastern Africa). There are also One Health designated degree and training programmes.
However, most countries lack the crucial mechanisms needed to coordinate activities across the human health, agricultural and environmental sectors. So practical applications of One Health have been ad-hoc.
Despite the many practical obstacles – geo-political, institutional and financial – a growing body of research confirms the public health and economic cost-benefits of this more joined-up approach.
The business case for funding One Health was compelling long before Covid. One study in 2014 estimated that investing in One Health to mitigate pandemic threats could yield savings of over $300 billion globally over the next century versus business-as-usual adaptation.22
A World Bank analysis back in 2012 estimated that bringing prevention and control systems in developing countries up to WHO standards would cost $1.9-3.4 billion per year globally. That expenditure was outweighed by the cost of zoonotic outbreaks: $6.7 billion was the average annual cost of the six that occurred between 1997 and 2009. Yet none of these – Nipah Virus (Malaysia), West Nile Fever (USA), SARS (Asia, Canada, etc), HPAI (Asia, Europe), BSE (US, UK), Rift Valley Fever (Tanzania, Kenya, Somalia) – reached serious epidemic proportions.
The Bank’s analysis concluded that the upfront investment of $3.4 billion improving veterinary and public health services could avoid over $30 billion in zoonotic disease response expenditure worldwide each year.23 Coincidentally, that more or less equates to the global value of the veterinary medicine market – put at $29.2 billion in 2020, it’s projected to grow by 7.4% a year from 2021 to 2028.24
A more recent report contrasts the cost of preparedness with the impact of Covid. By October 2020, responding to the pandemic had cost $11 trillion, with a future loss of $10 trillion in earnings, according to the Global Preparedness Monitoring Board, which was launched by the WHO and World Bank Group in 2018.25 By comparison, investing in preparedness would cost $5 per person per year – or about $39 billion.
Not only are the costs of monitoring and prevention significantly lower than reacting to pandemics and dealing with the socio-economic fallout. It would save and transform the lives of millions of the world’s poor who are sick, die prematurely and made poorer by endemic zoonoses and new outbreaks.
In search of more intelligent solutions
New and emerging technologies could also contribute to this more cost-effective, humane and sustainable strategy for combating zoonotic diseases worldwide. These technologies range from artificial intelligence (AI) and machine learning (ML) to gene editing, and they have applications in areas such as surveillance, diagnostics and food safety.
Surveillance is the first line of defence against new pathogens. Local, national, and regional networks already exist, and more need to be set up along One Health lines. They can use computational epidemiology to detect unusual patterns or clusters of illness and forecast the disease trajectory, giving health authorities more time to take preventative measures.
MOOD – Monitoring Outbreak events for Disease surveillance – is a collaborative project spanning Europe and North America. Begun in January 2020, it has a €14 million budget to develop new monitoring tools for detecting emerging diseases and the early signs of epidemics by the end of 2023.26 Epidemic intelligence systems use both official public health data and unofficial information from the media, social networks, scientific articles and labs. These non-official sources have proved more effective at detecting emergent diseases in recent years. The aim is to use big data and innovative disease modelling to analyse them, and share the tools worldwide.
Innovative diagnostic tools can also reinforce surveillance of known zoonoses by detecting re-emergence early. This can be achieved at relatively low cost, as shown in the Republic of Congo. The Wildlife Conservation Society, working with scientific institutes, developed a rapid and portable tool to detect Ebola on animal carcasses in 2017, as part of a wider $11 million programme. Without the need for veterinary personnel on site, it reduced the diagnostic turnaround time from several weeks to three days.27 The University of Manchester is also working with technology leaders and data science specialists to learn and apply the lessons from the Ebola outbreak.
Digitalisation opens up other opportunities for modernising infrastructure and systems for earlier detection of emerging zoonoses. For example, machine learning methods are being explored for using veterinary necropsy reports in surveillance.
R&D can also play a part in improving biosecurity, whether in farming or laboratories, where accidental transmission and escapes of pathogenic organisms have occurred (though there is no evidence of this in the case of Covid-19).
The environmental dimension
The UN Environment Programme argues that the main factor limiting the success of One Health so far has been the failure to integrate environmental science and policies alongside animal and human health Deforestation, population growth, urbanisation, climate crisis, food supply, biodiversity loss, soil degradation are inter-linked with each other and other anthropogenic drivers of zoonotic diseases.
The entire food chain is ripe for innovation. One of many potential interventions would be to increase the genetic resistance of livestock to invasive pathogens from wildlife. An Israeli biotech start-up is using gene editing-induced gene silencing technology – licensed by UK’s Tropic Biosciences – to protect chickens from avian influenza. Bird flu is a deadly zoonose that has led to the slaughter of millions of infected poultry as well as threatening human health.28
Governments can spur further research and innovation, as well as tightening regulation of the wildlife trade and food markets, which is happening in Asia. The UK’s delayed Environment Bill promises to stop the importation of goods from areas of illegally deforested land. Businesses would need to show that supply chains for products and ingredients – including soy, palm oil, beef, leather and other commodities – were free of deforestation. Campaigners and many companies want a clear deadline. The World Wildlife Fund is lobbying for a legally binding 2023 target.29
Parts of the food industry are investing in R&D and other activities to take the pressure off forests, by reducing reliance on palm oil, for example, and pledging to source supplies that are 100% certified sustainable and traceable. However, while some companies are making commendable progress, others, including some of the UK’s favourite brands, are making little or none, according to the WWF.30
UK scientists have also warned of the consequences of cuts in its international aid budget, which have forced the UK Research and Innovation Agency to halve funding for projects in developing countries from £245 million to £125 million. Work to reduce the risk from zoonotic diseases and antimicrobial resistance will be among the casualties.31
A ‘one planet’ approach
Controlling the emergence of zoonotic diseases will require collaboration at a global scale. It sounds utopian but there are some other encouraging initiatives.
PREZODE is a new initiative to create a global prevention and surveillance system for emerging zoonotic threats and pandemics. Launched in January 2021 at the One Planet Summit, it involves three French research institutes teamed with 10 others in Germany and the Netherlands. They have mobilised 1,000 researchers and practitioners on the ground, who will share findings with the aim of putting them into action more rapidly.32
In the US, the National Institute of Allergies and Infectious Diseases in 2020 launched a global network for multidisciplinary investigations into how pathogens spill over to cause disease in people. With a $17 million budget in its first year, CREID (Centers for Research in Emerging Infectious Diseases) has 10 centres working with peer institutions in the US and 28 other countries to develop reagents and diagnostics to improve detection.33
In November 2020 Germany was the first to invest in Food Systems 2030, a new multi-donor trust fund set up by the World Bank.34 It contributed €13 million to promote new agriculture and food models to boost food safety and early detection of zoonoses in the food chain.
With hunger on the rise, healthy diets unaffordable for the poor, and 30% of food produced being wasted, the world’s food systems are not fit for purpose, according to the Bank. Nor are they sustainable: accounting for around a quarter of global greenhouse gas emissions and close to 60% of biodiversity loss since the 1970s.
Breaking the cycle of pandemics – and panic and neglect – will require not just a global push towards a One Health approach. A holistic ‘one planet’ plan of action is needed for food and ecosystems, biodiversity and forestation, climate change and decarbonisation to secure a healthy planet for healthy people.