Europa and the Bull, Attic red figure, Tarquinia Museum, Italy, circa 480 BCE: Zeus, in the guise of a friendly bull, tempts the Phoenician princess Europa to climb onto his back; when she does, he carries her across the sea to Krete.

A recently published paper by Delia Grace, a veterinary epidemiologist and food safety expert at the International Livestock Research Institute (ILRI), outlines a pathway to develop the business case for One Health.

Grace says One Health can add value and reduce costs in five areas:
(1) sharing health resources between the medical and veterinary sectors
(2) controlling zoonoses in animal reservoirs
(3) early detection and response to emerging diseases
(4) prevention of pandemics
(5) generating insights and adding value to health research and development

Grace gives examples for each category along with preliminary estimates of the potential savings from adopting the One Health approach. The literature she reviewed suggests that one dollar invested in One Health can generate five dollars worth of benefits and a global investment of US$25 billion over 10 years could generate benefits worth at least US$125bn.

Grace argues that the time has come to make the bigger case for massive investment in One Health to transform the management of neglected and emerging zoonoses and to save the lives of millions of people and hundreds of millions of animals whose production supports and nourishes billions of impoverished people per annum. Her article draws on experiences of ILRI gathered through several One Health and Ecohealth projects over the last decade and incorporates findings from a literature review.

One Health is a broad movement that recognizes the fact that human, animal and ecosystem health are interdependent and that multidisciplinary collaborations are often necessary in order to attain optimum health solutions. But although One Health is well understood and appreciated, it has yet to gain large-scale traction in the medical and donor communities. Despite a large and growing body of evidence supporting the usefulness of One Health, the great majority of medical education, clinical practice, ancillary services, development programs and research continue to operate within disciplinary boundaries.

Grace’s article discusses the process of building a compelling business case for One Health. It presents a ‘Big Five’ framework for categorizing One Health problems and related interventions, estimates of the costs of the One Health problem as well as the likely costs and benefits of One Health interventions and recommendations for building a convincing business case for One Health.

Background
Relations among human, animal and environmental health have been recognized throughout the historical development of medicine on all continents. But as medicine developed into a profession, a separation grew between those who treated humans and those who treated animals, with human doctors given higher status.

In the 20th century, three major movements sought to bring these disciplines closer together: ‘One Medicine’, ‘Ecosystem Health’ or ‘Ecohealth’ (which adapted thinking from ecology and environmental management to the improvement of human health and wellbeing) and ‘One Health’, which arose because of increasing concern of disease emergence at the interface between animals, humans and ecosystems triggered by a series of disease emergencies of global importance in the 1990s, including severe acute respiratory syndrome (SARS), avian influenza and West Nile virus; One Health had strong participation from veterinary and, to a lesser extent, human public health.

One Health can be defined as the collaborative effort of multiple disciplines to attain optimal health for people, animals, and our environment. The disease theme of the CGIAR Research Program on Agriculture for Nutrition and Health, which is led by Grace, focuses on food-borne diseases and zoonoses but also goes beyond zoonoses and occupational hazards to consider such things as obesity and anthroponotic but agriculture-related diseases as being One Health issues (e.g. malaria, which is linked to irrigation but is not a zoonosis).

A ‘Big 5’ framework for One Health
1 Join up health resources: Share health resources between sectors
Sharing health resources across human and veterinary health sectors would appear to be an easy win. This is especially the case for laboratory facilities as most pathogens and chemical hazards are common to both humans and animals. Joint laboratory facilities are particularly important in developing countries where scarcity of human and financial resources challenge the sustained operation of laboratory resources. Second and third areas are shared education resources and surveillance systems.

Estimating the benefits of collaboration across medical and veterinary services is challenging. Human health expenditure in developing countries was estimated at US$521 billion in 2012. Estimations for veterinary health expenditure are less solid, but are appear to be in the order of US$1bn–2bn on public animal health services in developing countries. We assume joint operations can save around 10% of the combined medical and veterinary budget devoted to those functions amenable to sharing. Best available evidence suggests that laboratories, education and management of zoonoses are services that can be shared and that these constitute 5% of the human health budget and 40% of the veterinary health budget.

This implies that the total savings of joined-up services could be US$2.68bn per year. Given estimates of the cost of collaboration, net savings of around US$3bn imply gross savings of around US$4bn per year.

2 Control zoonoses in animal reservoirs
Historically, most major zoonoses that have been controlled successfully have concentrated on the animal reservoir. This includes diseases such as brucellosis, tuberculosis, rabies, salmonellosis, cysticercosis and trichinellosis.The median ratio of benefits to costs was around four to one, with human health benefits at least equal to animal health benefits and often greater.

Regarding the costs and benefits of controlling zoonoses in developing countries, a recent study by Grace estimates that around one in seven (14%) livestock in developing countries each year are currently or recently infected with one or more zoonoses and that each infection reduces their productivity by around 10%. According to the FAO, the value of livestock production in developing countries in 2012 was US$639bn per year at the time of their study, suggesting that the productivity losses related to zoonoses is around US$9.26bn per year.

In addition to morbidity, mortality is an important cause of loss for livestock. Livestock losses as well as sickness are high in developing countries, which currently lose approximately 68 million tropical livestock units (TLU) because of zoonoses. Assuming that the value of a TLU is US$366, this costs developing countries US$25bn per year.

The human health costs of zoonoses are typically equal to or greater than the livestock sector losses, a trend which is becoming more pronounced with time. A recent study by Grace suggests 2.2 million human deaths and 2.4 billion human illnesses a year from zoonoses, equaling losses of at least US$50 billion in 2013.

This implies that the annual costs of zoonoses may be US$9bn in lost productivity, US$25bn in livestock mortality and US$50bn from human health – rounded up to US$85bn in all per year. As the costs of control are typically one-fourth the benefits and a control program may extend for five to 10 years, the US$85bn in annual losses could be averted by an expenditure of US$21bn over this period (excluding discounting).

3 Detect disease outbreaks early 
Rapid response is key to reducing the cost of highly contagious disease outbreaks. While it is difficult to estimate the costs of a counterfactual, we can compare the costs of controlling of the bovine spongiform encephalitis (BSE) outbreaks in Britain and Canada and see that if control had been as timely and effective in the UK as in Canada, 88% of the costs could have been averted.

Comparisons of effectively and poorly controlled epidemics indicate that well-functioning surveillance systems and timely responses may reduce the cost of outbreaks by 95%. The World Bank estimates that outbreaks have cost on average US$6.7bn from 1997–2009. They estimate that a US$3.4bn investment in animal health systems per annum would support these systems so that they could function effectively and efficiently, enabling them to avert the losses incurred through delayed or inadequate response. A 95% reduction in costs amounts to US$6bn saved per year.

4 Prevent pandemics 

In addition to the ongoing losses from disease outbreaks, which have become the ‘new normal’, there is considerable concern over the possibility of a civilization-altering pandemic or plague.

These have occurred regularly but infrequently throughout history and pre-history, with the most recent example being the HIV pandemic. A landmark study by the World Bank of the possible impacts and costs of averting high-impact but low-probability pandemics drew the following conclusions.

A severe pandemic costing US$3 trillion may occur, on average, once in a hundred years.

If the investments in One Health systems are made and such a pandemic is prevented, the global expected benefits are US$30 billion per year. Every year, an investment of US$3.4 billion would produce an expected benefit of US$30 billion for the international community.

This expenditure of US$3.4bn on strengthening veterinary services would hence deliver two streams of benefits: averting major pandemics with an expected benefit of US$30bn and improving the timeliness of response to outbreaks with an annual expected benefit of US$6bn a year.

5 Add value to health research and development
One Health and Ecohealth approaches lead to better research and disease control programs as well as ecosystems better able to provide health as a regulatory service. Whilst a large and growing body of evidence supports the hypothesis that adopting both approaches improves the effectiveness and efficiency of health research and delivery, the costs and benefits of adopting these approaches, especially those that are highly participatory and multidisciplinary in nature, to research and development are difficult to quantify, and thus an important area for future research.

Conclusions
With a dearth of information on the burden of zoonoses, this preliminary review, first presented last year, developed the following initial (non-definitive) estimates of the possible costs of zoonoses, the investments needed to control them and the benefits derived therefrom:

A US$25bn annual investment over 10 years would generate annual benefits worth at least US$125bn (excluding discounting). Additional benefits include saved DALYs (disability adjusted life years), which reflect the disutility of illness, as well as conserved ecosystem health regulation through reduction of zoonoses spillover to wildlife.

Developing a comprehensive and credible ex ante assessment of the business case for One Health and Ecohealth approaches requires investment. A first step is to develop and evaluate metrics that capture the impact of zoonoses and emerging disease on human health, the livestock sector, the broader economy and ecosystem health regulation. Long-term solutions need to include the upgrading of reporting systems for disease prevalence and impacts to ensure quality, transparency and reliability.

Developing a detailed business case covering the economic case, options, risks and priorities for One Health investments would require a multidisciplinary team with skills in epidemiology, economics and an understanding of developing-country livestock sectors.

Grace estimates that a 5–10-person team of experts, supported by research assistants and information technology, could build the business case in one year, whilst 30 people would take just months.

She argues that a credible body of evidence about the costs, benefits and feasibility of controlling zoonoses would stimulate investments by donors and national governments as well as by the non-profit and private sectors.

Summary
Emerging and neglected zoonoses have often been managed sectorally, but recent decades have shown, in case after case, the benefits of One Health management. The growing body of evidence suggests the time has come to make the bigger case for massive investment in One Health to transform the management of neglected and emerging zoonoses, annually saving the lives of millions of people as well as hundreds of millions of animals whose production supports and nourishes billions of impoverished people.

Read the whole paper: The business case for One Health, by Delia Grace, Onderstepoort Journal of Veterinary Research 81(2), 2014, http://dx.doi.org/10.4102/ojvr.v81i2.725

This work was funded in part by support from the Ecosystem Services for Poverty Alleviation Programme (ESPA), which is funded by the UK’s Department for International Development (DFID), Economic and Social Research Council (ESRC) and Natural Environment Research Council (NERC).

For more on One Health, visit the One Health Initiative website, which posts a news item about this paper by Grace.

Delia Grace leads ILRI’s Food Safety and Zoonoses Program and a component of the CGIAR Research Program on Agriculture for Nutrition and Health called Agriculture-Associated Diseases.