Market incentives–not top-down regulation–needed to help poor farmers take advantage of East Africa’s burgeoning pig industry

Uganda railways assessment 2010

A family of pigs are at home on a section of overgrown railway track near Kumi, Uganda, September 2010 (photo on Flickr by John Hanson/US Army).

Editor’s Correction of 18 Jan 2012
Today we have corrected parts of this story to reflect the following comment from CRP 3.7 director Tom Randolph:

Lessons learned in other smallholder livestock systems—especially smallholder dairying in East Africa and India—is that a typical policy reaction to animal and public health challenges is to seek more regulation. The problem is that such regulation often proves to be toothless (i.e. cannot be effectively enforced by veterinary services) and ultimately anti-poor. We are pursuing alternative approaches that encourage farmers and other value chain actors to improve animal and public health-related practices by creating or exploiting market incentives rather than relying on top-down regulation. This will certainly be our approach as we engage in the Uganda smallholder pig value chain.’ — Tom Randolph, director of CGIAR Research Program on Livestock and Fish (CRP 3.7)

East Africa’s growing human population and rapid urbanization are creating new opportunities for small-scale farmers to make money from pig farming. According to Tom Randolph, an agricultural economist with the International Livestock Research Institute (ILRI), ‘pig production [in East Africa] is taking off and growing rapidly and there is a rising demand for pork and related products, particularly in Uganda.’ Uganda has more than 3 million pigs and over 1.1 million people across the country (17 per cent of households) are involved in pig rearing and trade in pork products.

Randolph was speaking at the ILRI Nairobi campus during a recent workshop to find ways of diagnosing and controlling the spread of cysticercosis, a disease caused by tapeworms that can cause seizures and epilepsy in people when they consume undercooked pork infected with the tapeworms. Inadequate disease control is one of the biggest challenges facing the informal pig industry in East Africa.

Most of the pork sold in this region is produced by small-scale farmers who keep 1 to 3 animals in ‘backyard systems’, and the rapid growth of urban areas is opening up new opportunities for small-scale producers to intensify their pork production to meet growing demand.

For farmers in the region, pigs are ‘a cash crop of livestock’ because they do not carry cultural and social values like cows and chickens. This means that pig farming, because of its nature as a commercial activity and the shorter production cycles of pigs, can offer significant economic benefits to smallholders. ‘By supporting pig farming, we will be helping women, who are the ones who typically tend to the pigs on these small farms, and families to improve their income and their nutrition,’ said Randolph.

Despite the great potential offered by poor farmers from pig farming, Randolph said ‘the sector remains largely “invisible” and poorly regulated because the region’s governments have not focused on developing it.’

Improvements needed in the sector include providing better breeds and improving marketing systems to capture the ‘value that is currently being leaked out of the system’. Dealing with diseases such as African swine fever and cysticercosis is also critical. ‘Early diagnosis of diseases,’ said Randolph, ‘will give confidence to consumers that the pork they buy is safe.’

See workshop presentation:

US-Kenyan team developing vaccine to protect African cattle against deadly East Coast fever

Dissecting ticks to extract parasites at ILRI

Staff of ILRI’s Tick Unit dissect ticks to extract the parasite Theileria parva, which causes East Coast fever in cattle (photo credit: Brad Collis).

A vaccine that protects cattle against East Coast fever, a deadly disease in eastern and central Africa, is being developed by scientists in Kenya working for the International Livestock Research Institute (ILRI) jointly with scientists at the Agricultural Research Service (ARS) Animal Disease Research Unit in Pullman, Washington, which is part of the United States Department of Agriculture (USDA). ARS is the USDA’s chief intramural scientific research agency. This research, which looks at combination vaccines for tick-borne diseases, supports USDA’s priority of promoting international food security.

Scientists are focusing on the tick that transmits the parasite responsible for East Coast fever. Because this host tick and its parasite are similar to the tick and parasite that cause babesiosis, commonly called Texas cattle fever, in the United States, developing a vaccine for East Coast fever could lead to a vaccine for Texas cattle fever, which is a serious illness for wild and domesticated animals, especially cattle.

In an initial study, scientists developed a polymerase chain reaction test that detects parasite DNA in ticks. They used tick populations that were produced at ILRI to have different susceptibilities to infection with the parasite. Two different strains of ticks—Muguga and Kiambu—were compared. The Muguga ticks had a low level of parasitic infection, whereas the Kiambu ticks were highly susceptible.

Understanding genetic differences between these two tick populations could lead to the identification of proteins that might be good targets for a vaccine to help control East Coast fever.

This international partnership is part of a global community effort to control diseases that limit food and fiber production. Although East Coast fever isn’t currently a problem in the United States, this collaborative research aids in keeping the US and other countries free of the disease. Results of this collaborative research may be applied to help control similar parasitic diseases.

Findings from this research were published in Gene and in the Journal of Medical Entomology.

Read more at the United States Department of Agriculture Agricultural Research Service: Partnership focuses on developing East Coast fever vaccine, 4 Oct 2011.

Read more about this research in the October 2011 issue of Agricultural Research Magazine.

Read more about this project on ILRI’s website.

CGIAR research coalition approves six programs to boost global food security

CGIAR Research Program 3.7 on livestock and fish

The developing world’s supplies of wheat, livestock, fish, roots, tubers, and bananas, along with the nutrition of its poorer communities and the food policies of its governments, should be enhanced in the coming years by new funding approved by the Consultative Group on International Agricultural Research (CGIAR), the world’s largest international agriculture research coalition.

The CGIAR has approved six new programs, totalling some USD957 million, aimed at improving food security and the sustainable management of the water, soils and biodiversity that underpin agriculture in the world’s poorest countries. The newly created CGIAR Fund is expected to provide USD477.5 million, with the balance of the support needed likely to come from bilateral donors and other sources.

The six programs focus on sustainably increasing production of wheat, meat, milk, fish, roots, tubers and bananas; improving nutrition and food safety; and identifying the policies and institutions necessary for smallholder producers in rural communities, particularly women, to access markets.

The programs are part of the CGIAR’s bold effort to reduce world hunger and poverty while decreasing the environmental footprint of agriculture. They will target regions of the world where recurrent food crises—combined with the global financial meltdown, volatile energy prices, natural resource depletion, and climate change—undercut and threaten the livelihoods of millions of poor people.

‘More and better investment in agriculture is key to lifting the 75 per cent of poor people who live in rural areas out of poverty,’ said Inger Andersen, CGIAR Fund Council chair and World Bank vice-president for sustainable development. ‘Each of these CGIAR research programs addresses issues that are fundamental to the well-being of poor farmers and consumers in developing countries. Supporting such innovations is key to feeding the nearly one billion people who go to bed hungry every night.’ CGIAR Fund members include developing and industrialized country governments, foundations and international and regional organizations.

Each of the research programs, proposed by the Montpellier-based CGIAR Consortium of International Agricultural Research Centers, is working on a global scale by combining the efforts and expertise of multiple members of the CGIAR Consortium and involving some 300–600 partners from national agricultural research systems; advanced research institutes; non-governmental, civil society and farmer organizations; and the private sector. By working in partnership on such a large scale, the CGIAR-plus=partners effort is unprecedented in size, scope of the partnerships and expected impact.

The six new programs, each implemented by a lead centre from the CGIAR Consortium, join five other research endeavours approved by the CGIAR in the past nine months (on rice, climate change, forests, drylands, and maize) as part of the CGIAR’s global focus on reducing poverty, improving food security and nutrition and sustainably managing natural resources. Each of the six programs described below was approved with an initial three-year budget.

CGIAR Research Program 3.7 on livestock and fish

Meat, Milk and Fish (USD119.7m) will increase the productivity and sustainability of small-scale livestock and fish systems to make meat, milk and fish more profitable for poor producers and more available and affordable for poor consumers. Some 600 million rural poor keep livestock while fish—increasingly derived from aquaculture—provide more than 50 per cent of animal protein for 400 million poor people in Africa and South Asia. This program will be led by the International Livestock Research Institute (ILRI), based in Africa.

Agriculture for Improved Nutrition and Health (USD191.4m) is designed to leverage agriculture improvements to deal with problems related to health and nutrition. It is based on the premise that agricultural practices, interventions and policies can be better aligned and redesigned to maximize health and nutrition benefits and reduce health risks. The program will address the stubborn problems of under-nutrition and ill-health that affect millions of poor people in developing countries. Focus areas include improving the nutritional quality and safety of foods in poor countries, developing biofortified foods and generating knowledge and techniques for controlling animal, food and water-borne diseases. This program will be led by the International Food Policy Research Institute (IFPRI), based in the USA, with the health aspects led by ILRI.

Wheat (USD113.6m) will create a global alliance for improving productivity and profitability of wheat in the developing world, where demand is projected to increase by 60 per cent by 2050 even as climate change could diminish production by 20 to 30 per cent. Accounting for a fifth of humanity’s food, wheat is second only to rice as a source of calories for developing-country consumers and is the number one source of protein.

Aquatic Agriculture Systems (USD59.4m) will identify gender-equitable options to improve the lives of 50 million poor and vulnerable people who live in coastal zones and along river floodplains by 2022. More than 700 million people depend on aquatic agricultural systems and some 250 million live on less than USD1.25 per day. The program will explore the interplay between farming, fishing, aquaculture, livestock and forestry with efforts focused on linking farmers to markets for their agricultural commodities.

Policies, Institutions and Markets (USD265.6m) will identify the policies and institutions necessary for smallholder producers in rural communities, particularly women, to increase their income through improved access to and use of markets. Insufficient attention to agricultural markets and the policies and institutions that support them remains a major impediment to alleviating poverty in the developing world, where in most areas farming is the principal source of income. This initiative seeks to produce a body of new knowledge that can be used by decision-makers to shape effective policies and institutions that can reduce poverty and promote sustainable rural development.

Roots, Tubers and Bananas (USD207.3m) is designed to improve the yields of farmers in the developing world who lack high-quality seed and the tools to deal with plant disease, plant pests and environmental challenges. Over 200 million poor farmers in developing countries are dependent on locally grown roots, tubers and bananas for food security and income, which can provide an important hedge against food price shocks. Yet yield potentials are reduced by half due to poor quality seed, limited genetic diversity, plant pests and disease and environmental challenges.

‘These programs mark a new approach to collaborative research for development,’ said Carlos Perez del Castillo, CGIAR Consortium Board Chair. ‘They bring together the broadest possible range of organizations to ensure that research leads to development and real action that improves people’s lives.’

Note: The Consultative Group on International Agricultural Research (CGIAR) is a global partnership that unites organizations engaged in research for sustainable development with the funders of this work. The funders include developing- and industrialized-country governments, foundations and international and regional organizations. The work they support is carried out by 15 members of a Consortium of International Agricultural Research Centers, in close collaboration with hundreds of partner organizations, including national and regional research institutes, civil society organizations, academia and the private sector.

Goat plague next target of veterinary authorities now that cattle plague has been eradicated

Last known occurrences of rinderpest since 1995. IFPRI Discussion Paper 00923, November 2009, ‘The Global Effort to Eradicate Rinderpest’ by Peter Roeder and Karl Rich, 2020 Vision Initiative, a paper prepared for a project on Millions Fed: Proven Successes in Agricultural Development ( (illustration credit: FAO GREP).

Jeffrey Mariner, former advisor for special action areas to the Pan-African Rinderpest Campaign and current senior scientist at the International Livestock Research Institute (ILRI), based in Kenya, is one of several authors of a paper published in the current issue of Veterinary Record on the subject of the rising importance of building a systematic program to eradicate a goat disease known as ‘peste des petits ruminants’ (PPR), or goat plague.

The editorial in the Veterinary Record explains why goat plague is replacing cattle plague among the world’s verterinary researchers.

‘This week saw a landmark in the history of the veterinary profession and, more specifically, its management of disease threats to food security. The Food and Agriculture Organization of the United Nations (FAO) announced on June 28, 2011 that its member countries had passed a resolution declaring rinderpest to have been eradicated globally, building on an announcement in May that the World Organisation for Animal Health (OIE) at its General Session had passed a resolution to the effect that all countries in the world had been formally accredited as free from rinderpest.

‘These events mark the fact that the virus is no longer present in any of its natural hosts on this planet. No longer is it a cause of disease or a constraint to international trade. What is not generally appreciated is that the eradication of rinderpest has yielded benefits that surpass virtually every other development programme in agriculture, and will continue to do so into the future. For example, a preliminary study in Chad shows that over the period 1963 to 2002, each dollar spent on rinderpest eradication led to a benefit of at least US $16, a conservative estimate that only takes into account the benefits from reduced cattle deaths and resulting herd growth, without including secondary impacts on the economy as a whole (Rich and others 2011).

‘Building on the dramatic success of the global effort to eradicate rinderpest we now wish to draw attention to a related but significantly different morbillivirus disease, peste des petits ruminants (PPR), also known variously as goat plague, pseudorinderpest, pneumoenteritis and kata. A comprehensive review of the disease by research scientists at the Institute for Animal Health Pirbright laboratory (IAH Pirbright) is published in this issue of Veterinary Record and explains the scientific basis for considering eradication (Baron and others 2011).

‘Until relatively recently PPR was considered to be a parochial disease of west Africa; however, its range is now recognised to affect most of sub-Saharan Africa as well as a swathe of countries from Turkey through the Middle East to south Asia with recent alarming extensions into north Africa, central Asian countries and China. Capable of causing very high mortality in susceptible goat herds and sheep flocks, PPR exerts a major economic impact on farmers and their families dependent on small ruminants. There is a growing appreciation that PPR is a most serious constraint to the livelihoods of farming families and to food security in affected countries and that its control warrants significant investment. An additional concern is the lethal nature of PPR infection in wildlife species, many of which are endangered or threatened, including gazelles and mountain caprines. Until recently, losses were apparently restricted to extensive wildlife collections in the Middle East but now outbreaks are being recognised in free-ranging species such as the Sindh ibex (Capra aegagrus blythi) in Pakistan. It is probable that many cases of wildlife disease have passed unnoticed in remote locations.

‘Encouraged by what has been achieved with rinderpest and an understanding that the factors that marked rinderpest eradication as feasible apply equally to PPR, we believe that a global programme for the total eradication of PPR should be established as an international undertaking without delay. The FAO has recently hosted a number of symposia and workshops at which participating chief veterinary officers have unanimously requested such a global initiative against PPR. . . .’

Read the whole editorial in Veterinary Record: Rinderpest eradicated; what next?, 2011: 169. DOI:10-11 doi:10.1136/vr.d4011

Read a paper by Peter Roeder and ILRI scientist Karl Rich, The global effort to eradicate rinderpest, IFPRI Discussion Paper 00923, November 2009, prepared for the project on Millions Fed: Proven Successes in Agricultural Development.

Deadly rinderpest virus today declared eradicated from the earth–‘greatest achievement in veterinary medicine’

At OIE, ILRI's Jeff Mariner and others responsible for the eradication of rinderpest

At the 79th General Session of the United Nations World Organisation for Animal Health (OIE), in Paris in May 2011, ILRI’s Jeff Mariner (second from right) stands among a group of distinguished people heading work responsible for the eradication of rinderpest, a status officially declared at this meeting (image credit: OIE).

Several world bodies are celebrating what is being described as ‘the greatest achievement in veterinary medicine’: the eradication of only the second disease from the face of the earth.

The disease is rinderpest, which means ‘cattle plague’ in German. It kills animals by a virus—and people by starving them through massive losses of their livestock.

‘In the nineteenth and twentieth centuries,’ reports the United Nations Food and Agriculture Organization (FAO), ‘the disease devastated parts of Africa, triggering extensive famines. . . . After decades of efforts to stamp out a disease that kept crossing national borders, countries and institutions agreed they needed to coordinate their efforts under a single, cohesive programme. In 1994, the Global Rinderpest Eradication Programme (GREP) was established at the UN Food and Agriculture Organization (FAO), in close association with the World Organization for Animal Health (OIE).

‘Excellent science, a massive vaccination effort, close international coordination and the commitment of people at all levels have helped make rinderpest eradication possible.

‘On June 28, 2011, FAO’s governing Conference will adopt a resolution officially declaring that rinderpest has been eradicated from animals worldwide. The successful fight against rinderpest underscores what can be achieved when communities, countries and institutions work together.’

Nobel Laureate Peter Doherty

Australian Peter Doherty, 1996 winner of the Nobel Prize for Medicine who served on the board of trustees of the International Laboratory for Research on Animal Diseases (ILRAD), a predecessor of  ILRI (photo credit: published on the Advance website).

Australian Peter Doherty, an immunologist who is the only veterinarian to win the Nobel Prize, for Physiology or Medicine, in 1996, and who served as chair of the board of trustees research program of the International Laboratory for Research on Animal Diseases (ILRAD), a predecessor of the International Livestock Research Institute (ILRI), is attending the FAO ceremonies this week. In an interview with FAO, he said:

Vaccine research is currently a very dynamic area of investigation and with sufficient investment and the enthusiastic participation of industry partners at the “downstream” end, we can achieve even better vaccines against many veterinary and human diseases.

The Washington Post in May reported that ‘the World Organization for Animal Health, at its annual meeting in Paris on Wednesday, accepted documentation from the last 14 countries that they were now free of rinderpest. The organization, which goes by its French acronym, OIE, was started in 1924 in response to a rinderpest importation in Europe.

‘The most recent recorded outbreak occurred in Kenya in 2001. Much of the past decade has been spent looking for new cases, in domesticated animals and in the wild, wandering herds of ungulates, or hoofed animals, in East Africa. The last place of especially intense surveillance was Somalia, where the final outbreak of smallpox occurred in 1977.

‘“There are a huge number of unsung heroes in lots of countries that made this possible,” said Michael Baron, a rinderpest virologist at the Institute for Animal Health in Surrey, England. “In most places, they were ordinary veterinary workers who were doing the vaccination, the surveillance, the teaching.”

‘Three things made rinderpest eradicable. Animals that survived infection became immune for life. A vaccine developed in the 1960s by Walter Plowright, an English scientist who died last year at 86, provided equally good immunity. And even though the virus could infect wild animals, it did not have a reservoir of host animals capable of carrying it for prolonged periods without becoming ill.

‘In 1994, the FAO launched an eradication program that was largely financed by European countries, although the United States, which never had rinderpest, also contributed money. The effort consisted of massive vaccination campaigns, which were made more practicable when two American researchers made a version of the Plowright vaccine that required no refrigeration. . . .’

One of those researchers was Jeffrey Mariner, now working at ILRI, in Nairobi, Kenya. Mariner also helped in surveillance work ‘with a technique called “participatory epidemiology” in which outside surveyors meet with herdsmen and ask open-ended questions about the health of their animals and when they last noticed certain symptoms.

‘“It was local knowledge that really helped us trace back the last places where transmission occurred—sitting down underneath a tree in the shade, listening to storytelling,” said Lubroth, of the FAO. . . .’

Read the whole article in the Washington Post, Rinderpest, or ‘cattle plague,’ becomes only second disease to be eradicated, 27 May 2011.

Read FAO’s interview of Peter Doherty: Healthier animals, healthier people, June 2011.

Short film illustrates expanded, agile partnerships behind recent disease research breakthrough

This short (5-minute) film, ‘Battling a Killer Cattle Disease’, produced by the International Livestock Research Institute (ILRI), provides background and context for a recent research breakthrough made at ILRI’s animal health laboratories in Nairobi, Kenya, and at their partner institutions in the UK and Ireland. The research was funded over 7 years in large part by the Wellcome Trust in addition to the Consultative Group on International Agricultural Research (CGIAR).

Trypanosomosis is a wasting disease of livestock that maims and eventually kills millions of cattle in Africa and costs the continent billions of dollars annually.

In 2011, a group of geneticists at these collaborating institutions identified two genes that enable Africa’s ancient N’Dama cattle breed to resist development of the disease trypanosomosis when infected with the causative, trypanosome, parasite.

The team members were able to make use of the latest gene mapping and genomic technologies because they had the genetic systems and experimental populations of livestock in place to do so as these technologies came on stream.

Eventually, these results should make it easier for livestock breeders in Africa to breed animals that will remain healthy and productive in areas infested by the disease-carrying tsetse fly.

The international team that came together in this project is an example of the disciplinary breadth as well as agility needed to do frontline biology today. In this work, the team developed several new research approaches and technologies that were needed to unravel some fundamental biological issues, with likely benefits for many African farmers and herders.

Those interviewed in the film include Harry Noyes, at the University of Liverpool; Alan Archibald, at the Roslin Institute at the University of Edinburgh; Andy Brass, at the University of Manchester; and Steve Kemp and Morris Agaba, at ILRI.

Amid soaring meat costs, officials from East Africa and Middle East seek plan to keep animal diseases from disrupting livestock trade

Orma Boran cattle crossing a river in Kenya

New approach to Rift Valley fever outbreaks aims to ensure food safety as region boosts livestock imports from Africa (photo credit: ILRI/Dolan)

With increased trade in livestock products offering a possible antidote to high food prices, livestock experts from the Middle East and 12 African countries are meeting this week (13-16 June, 2011) in Dubai to develop a strategy that eliminates the need to impose devastating bans on livestock imports from the Horn of Africa, as prevention against the spread of Rift Valley fever. The strategy should expedite the flow of livestock products while increasing safety of the overall livestock trade in the region.

Convened by the African Union’s Interafrican Bureau for Animal Resources (AU-IBAR), the International Livestock Research Institute (ILRI) and the United States Agency for International Development (USAID), the workshop will encourage officials and livestock traders to use a simple ‘Decision Support Planning Tool’ to guide and moderate their responses to Rift Valley fever outbreaks.

The ‘decision support tool’ for Rift Valley fever was developed by 30 experts and decisions-makers from across the Horn of Africa with technical assistance from researchers at ILRI, the United Nations’ Food and Agriculture Organization (FAO), and other partners. The tool will be used by chief veterinary officers and other national decision-makers. Its framework identifies the sequence of events likely to occur as the risk of a disease outbreak increases.

Rift Valley fever is a mosquito-borne virus found in eastern, western and southern Africa, Yemen and Saudi Arabia. Epidemics emerge periodically with prolonged rains. Climate and land-use changes could make outbreaks more frequent. A study done by ILRI economists Karl Rich and Francis Wanyoike indicated that the Rift Valley fever outbreak in 2007 cost Kenya at least USD32 million.

‘We must avoid unnecessary disruptions in agricultural trade between East Africa and the Middle East,’ said Ahmed El Sawalhy, director of AU-IBAR. ‘Livestock products must be safe and action concerning disease outbreaks must be in line with the actual threat.’ To this end, an animal health certification model suitable for pastoral livestock production systems and that promotes OIE standards has been developed by AU-IBAR in partnership with FAO and the Royal Veterinary College, London. The model is based on risk assessment and involves integration of both upstream animal health inspection and certification at entry points, markets and at the quarantines.

Time is also of critical importance in prevention and control of transboundary animal diseases. ‘In the last Kenyan Rift Valley fever outbreak, control measures were implemented late—not until there were definitive signs of an outbreak,’ said Jeffrey Mariner, an epidemiologist at ILRI. ‘This tool links early warning signs to control measures that can be implemented before animals or people begin falling ill. The new tool could reduce the impact of Rift Valley fever, and maybe even prevent some local outbreaks and has the potential to prevent the spread of Rift Valley fever through trade.’

‘The good news,’ says Bernard Bett, an epidemiologist at ILRI, ‘is that the impact of Rift Valley fever can be mitigated with early action during an outbreak, but veterinary officers and  decision-makers need to know what interventions to implement—and when—as the  stages of an epidemic  unfold.’

Rift Valley fever is best prevented through animal vaccination. But vaccines are expensive and few governments are willing to pay for expensive vaccines unless evidence indicates an epidemic is imminent. Regional cooperation is required to build consensus on managing the disease and to prevent trade disruptions.

Larry Meserve, USAID/EA’s regional mission director commented, ‘President Obama’s Feed the Future initiative aims to increase food security throughout Africa. To succeed, we must all help to improve the capacity of leadership in the Horn of Africa to anticipate potentially disastrous events like disease epidemics so that appropriate preventive or mitigating measures are taken before it is too late. Livestock is a vital staple crop in this part of the world, and both the private and public sectors have to do everything possible to prevent unnecessary disruptions in the trade of livestock and other commodities.’

Visit the official workshop blog site:

New PNAS-published study discloses the ‘hot spots’, ‘warm spots’ and ‘cold spots’ of global livestock disease risk

Mozambique, Garue, Lhate village

Small-scale livestock-dependent agriculture in developing countries makes up one of three trajectories of global disease risk; here, cattle belonging to a widowed farmer in Garue, Mozambique, are brought in for the night by a herdsboy (photo credit: ILRI/Mann).

‘Current drivers and future directions of global livestock disease dynamics’ is a special feature published in the (online) 16 May 2011 issue of the Proceedings of the National Academy of Sciences (PNAS) of the USA. The authors of the paper are Brian Perry, Delia Grace and Keith Sones.

Irish veterinary epidemiologist Delia Grace leads a team researching animal health and food safety for trade at the International Livestock Research Institute (ILRI), based in Nairobi, Kenya.

In the PNAS paper, the authors write: ‘The current era of globalization is seeing unprecedented movements of people, products, capital and information. Although this has obvious implications for economies and ecosystems, globalization also affects the health of people and animals. This paper reviews changing patterns of livestock disease over the last two decades, discusses the drivers of these patterns, and plots future trajectories of livestock disease risk in an effort to capitalize on our understanding of the recent past and provide a guide to the uncertain future.’

While acknowledging the complexity of disease dynamics, the authors point to three main drivers of changing livestock disease dynamics: ecosystem change, ecosystem incursion, and movement of people and animals. Underlying these dynamics are the growing demand for livestock products (the Livestock Revolution) and increasing human population size.

The authors identify three trajectories of global disease dynamics:
‘(i) the worried well in developed countries (demanding less risk while broadening the circle of moral concern)
‘(ii) the intensifying and market-orientated systems of many developing countries, where highly complex disease patterns create hot spots for disease shifts
‘(iii) the neglected cold spots in poor countries, where rapid change in disease dynamics is less likely but smallholders and pastoralists continue to struggle with largely preventable and curable livestock diseases.’

On the topics of major trends in disease dynamics, the authors point out that ‘From a centuries-long and whole-world perspective, human wealth and health continue to improve, and animal health parallels this, showing an overall dramatic decline of infectious disease and shift to noncommunicable diseases. (This has been called the second epidemiological transition; the first epidemiological transition was 10,000 y ago, when human settlement led to a surge in zoonoses and crowd-related diseases.)’

However, the authors also say that ‘Although control and management of many endemic diseases in rich countries have improved, new diseases such as BSE and HPAI have emerged. Some consider that we face a third epidemiological transition of disastrous consequence in which globalization and ecological disruption drive disease emergence and reemergence; as occurred in the first epidemiological transition (associated with neolithic sedentarization and the domestication of livestock), the worst of the emerging diseases are likely to be zoonotic.’

The authors go on to consider ‘the drivers with greatest influence on livestock disease dynamics, namely increasing human population size and prosperity and the related demand-driven Livestock Revolution. . . . [W]e identify three overarching sets of animal diseases dynamics and associated control. Each system is facing different risks to livestock health, each has different determinants of disease status and capacity to respond, and each requires different approaches to resolve them.’

‘In the background,’ they say, ‘is the significant component of the world’s livestock enterprises in the hands of the very poor, for whom intensification is just not a realistic option and who are likely to be most vulnerable to disease resurgence. . . .

‘Although we call these [very poor livestock] systems cold spots for disease dynamics and emergence, they are inevitably hot spots for endemic diseases, periodic epidemics (such as Newcastle disease, which regularly wipes out village flocks), and neglected zoonoses, which significantly impact on human health. Because of the low densities of livestock, their remoteness, and the slow change in husbandry practices, these are probably not hot spots for emerging diseases. . . .

‘This review is prognostic rather than therapeutic, presenting implications for livestock disease in the 21st century. In an increasingly globalized world, deepening of the existing balkanization of livestock health status will create inevitable instability. The main challenges are (i) to speed the convergence of livestock health between the intensifying and intensified regions through improved coordination, communication, and harmonization and (ii ) to improve resilience of smallholder livestock systems, including the support of viable exits from livestock keeping.’

Read the whole paper in the Proceedings of the National Academy of Sciences: Current drivers and future directions of global livestock disease dynamics, by Brian Perry, Delia Grace and Keith Sones, 16 May 2011.

Read an ILRI brief: Why animals matter to health and nutrition, February 2011.

Read another ILRI News Blog article related to this topic: Adapting agriculture to improve human health—New ILRI policy brief, 21 February 2011.

Read an ILRI news release: Livestock boom risks aggravating animal ‘plagues,’ poses growing threat to food security and health of the world’s poor, 2 February 2011.

Rational drug use by vets and farmers can control trypanosomosis, ‘the malaria of cattle’ in Africa

Livestock keepers in West Africa rely largely on treating their cattle with drugs to protect them from trypanosomosis, a wasting disease transmitted by the tsetse fly. But parasite resistance to these drugs has emerged in many areas.

This 13-minute film by the International Livestock Research Institute (ILRI) outlines good practices for improving the use of drugs and slowing the emergence of resistance. These practices, which are based on rational drug use, an approach from human health now adapted for animal care, are clearly explained so that veterinary workers and farmers can treat animals safely. Rational drug use can be combined with other methods that reduce the numbers of tsetse flies to further slow the spread of resistance to trypanocidal medicines.

This is one of three ILRI films telling the story of the current state of the war against a disease that is so deadly and widespread that farmers call it ‘the malaria of cattle’.

Forestalling the next plague: Building a first picture of all diseases afflicting people and animals in Africa

Typical mixed crop-livestock farming of western Kenya

An ILRI-Wellcome project is investigating the disease pathogens circulating in both people and animals in the communities outside the border town of Busia, Kenya, where smallholders mix crop growing with livestock raising (photo credit: ILRI/Pye-Smith).

A project funded by the Wellcome Trust on zoonotic diseases was broadcast last week on an Australian television program called ‘Catalyst’. The show ran on Thursday, 10 March 2011, at 20:00 Australian time. The research described in the program is supported by the International Livestock Research Institute (ILRI), where the project’s principal investigator, Eric Fevre, is hosted.

The television program interviews Fevre and his colleagues Lian Doble, a veterinarian managing laboratory work in western Kenya, and  Appolinaire Djikeng, technology manager of a Biosciences eastern and central Africa (BecA) Hub, located on ILRI’s Nairobi, Kenya, campus.

Fevre and Doble and their team are investigating what disease pathogens of both people and animals are circulating near the border town of Busia, a very poor, densely populated area whose communities mix crop growing with livestock raising on small plots of land. Research such as this that is looking at both human and animal diseases is rare but urgently needed because the close relations of people and farm animals in many poor regions, as well as the existence of monkeys and other wildlife nearby, is a ‘recipe for diseases’ jumping from animals to people. If we’re going to manage to forestall another zoonotic plague such as bird flu or HIV/AIDS, we’re going to have to conduct more of such ‘one health’ investigations that look at exactly what diseases are being transmitted between animals and people. The research project in western Kenya is part of a larger study being conducted by the BecA Hub to look at diseases of animals and people across eastern Africa. The BecA Hub team is using genomics and meta-genomics, and ‘4 million bucks of computing power,’ to build a picture of the complex relations of disease pathogens circulating in the region.

Eric Fevre and pit latrine in Busia, Kenya

Eric Fevre, who leads the ILRI-Wellcome project investigating the disease pathogens circulating in both people and animals in Busia, points out a pit latrine frequented by pigs as well as people, where disease transmission between the two species is most likely to occur (photo credit: ILRI/Pye-Smith).

A transcript of the Australian television program on this research follows.

Africa, the cradle of humanity and renowned for its wildlife. It could also be the origin of the next global pandemic. It’s long been known that people and animals living close together—well, that’s a recipe for disease. But exactly which diseases? And if new diseases are creeping into the system? Well, that’s something they’re trying to find out here in western Kenya. They’re called zoonotic diseases: infections that can jump from animals to people.

Eric Fevre
There are lots of zoonotic infections. In fact, about 60 per cent of all human diseases are of zoonotic origin.

So this team headed by Eric Fevre is taking a much closer look at the health of people and livestock in a densely populated region of western Kenya.

Eric Fevre
It seems to be obvious that zoonotic infections will occur more in people who keep livestock than in those who don’t. Whether that’s the case has never been formally established.

Lian Doble
If you look around here you don’t see the cattle in a field, in a fenced field or in a barn away from the people. Cattle are tethered within the compound that everybody’s working in, the chickens are loose around, going in and out of the houses. It’s a much more integrated system than anything we really see at home.

The kinds of problems that this environment creates are readily apparent.

Eric Fevre
We’re in a mixed crop-livestock production system where people are keeping a few animals. And as you can see behind me here, it’s the rainy season and people have recently planted their new crops. And this is an area of interaction between the croplands and the animals. And you can see behind over there behind those fields is some forest. And there might be a watercourse flowing through that forest, for example, where the animals are going to water. And that’s where the exciting things happen from a disease transmission point of view.

Part of the team focus on human health, taking a range of samples from people in the village as well as a detailed account of their medical history and current living situation. Meanwhile, others in the team have a look at the livestock.

Lian Doble
What we do know is that there are a large number of diseases that circulate between animals and humans. The problem is that a lot of these diseases cause signs which are very similar to other human diseases like malaria and human tuberculosis. What isn’t known is actually how many of the diseases that are mainly diagnosed as malaria actually are another disease caused by the pathogens found in cattle. So we’re just trying to find out what diseases she has and what are shared with the people that she lives with.

Paul Willis
And does she look healthy?

Lian Doble
She’s feisty and she’s quite healthy so we’ll see what she might have been carrying. And we can tell you later in the lab.

Samples are taken back to field laboratories in the town of Busia on the Ugandan border.

The ILRI-Wellcome Trust laboratory in Busia, Kenya

The ILRI-Wellcome Trust animal-human laboratory in Busia, Kenya (photo credit: ILRI/Pye-Smith).

Eric Fevre
In this place we’ve got a human and an animal lab next door where we process the material that comes in from the field. One of the things that we really need to do is look at fresh material. Because once the samples get a bit old, the parasites become a bit difficult to identify. And the second important thing is that we of course feed back to the participants of our study. So results that we get in the lab here are used directly by the clinicians working in the field to decide what treatments they should be giving people. So that’s one of the direct ways that our research project feeds back into the community.

This detailed look at the community health of a whole region is showing many expected results, and a few surprises.

Eric Fevre
One of the diseases that we’re testing for is brucellosis. And looking at the official reports there isn’t any brucellosis in this region. But we have detected brucellosis both in animals and in people and so already that’s what’s telling us that there are things circulating here that official records don’t pick up.

There seems to be a lot of malaria around, but Eric’s team are finding that many cases are masking something much more sinister.

Eric Fevre
Often it won’t be malaria. It will be something else. And there are a multitude of different pathogens that cause fever of the type that malaria also causes. And that’s a real problem. Because somebody with a low income might need to, say, sell one of their animals to then go to the clinic, get a diagnosis, buy some anti-malarial drugs. They don’t work because the person actually has sleeping sickness. So they go back to a different clinic. Or to a traditional healer. They get drugs that don’t work for the infection that they have. And so on and so on, five, six, seven times, travelling maybe ten kilometres each time. That’s a huge economic burden on them. And then finally they get properly diagnosed when they’re in the late stage of their infection. And it would have been much easier to treat them if they’d have been caught earlier on.

It’s a very complex picture that is emerging, one that could be simplified by some basic technology.

Lian Doble
Thirty per cent of our participants don’t have access to a latrine. You can imagine what that means. And that’s something that could be very actually quite easily sorted out with some education and some money and would sort out all sorts of other diarrhoeal diseases, which are one of the huge killers of young children in Africa.

Biosciences eastern and central Africa hub platform

One of the ultra-modern laboratories at the Biosciences eastern and central Africa (BecA) Hub ‘platform’ hosted and managed by ILRI in Nairobi, Kenya (photo credit: ILRI/White).

Back in Nairobi another team is taking a different look at the spread of diseases across east Africa.

Appolinaire Djikeng heads up a team collecting samples of animals and people from a wide swath across Kenya.

Appolinaire Djikeng
So essentially at the moment we are trying to cover the east African region. But of course we would like to once we establish our processes and data management skills and data analysis skills we like to expand this to other parts of Africa.

The first step in the labs is to figure out exactly what spread of diseases are present in their samples.

Appolinaire Djikeng
You are able to go in there, look at the, the complex composition of the viruses, at the pathogens or at the small organisms that exist in them in doing it that way you are able to come up with a catalogue of potential organisms that exist in there.

And this analysis goes deep into the DNA of the viruses and pathogens that are found, tracking minute changes in their genetic make-up that allows Appolinaire’s team to follow the spread of individual strains of a disease.

Appolinaire Djikeng
We have a reasonably good bioinformatic infrastructure here for storing that data and extracting them, looking at specific parameters from that particular data base. With so many samples from such a wide geographical area and with so much information for each individual sample these guys are dealing with a lot of data and so they brought in four million bucks worth of computing grunt. With so many samples from such a wide geographic area and with so much information for each individual sample these guys are dealing with a lot of data. So they brought in four million bucks worth of computing grunt.

There are several teams looking at zoonotic diseases in Kenya, but the impact of their work is global.

Appolinaire Djikeng
The threat of emerging and re-emerging infectious diseases are no longer restricted to countries like central Africa or sub-Saharan Africa So I think now we have to put this work in the context of the global effort across the world. Trying to make sure that even remote parts of the area do have resources and capabilities to begin to do good and accurate diagnostics of what could be emerging.

Eric Fevre
We actually use the data that we gather to, to try and understand how these things are being transmitted, how the fact that your animal has this disease impacts on your risk at a population scale. And, and use that to then try and understand the, the process of transmission of these diseases.

Lian Doble
The next big disease problem is very likely to be a zoonotic disease so doing this sort of work and then leaving it isn’t an option. It needs to be ongoing and, and build. This is the start of something and we’ll build on it from here.

Download this Catalyst show from Australia’s ABC website (select ‘Zoonosis’ 10/3/2011).

And check out a blog by Paul Willis about the adventures of filming in Kenya’s border town of Busia: Coming to an end, 7 March 2011.

Here’s some of what Paul Willis has to say in his blog about this film project:
‘Busia is a hard place; a border crossing town riddled with grinding poverty and hard living. The main street, the only sealed road through town, is frequently clogged with a seemingly endless string of trucks waiting to cross the border into Uganda. Because Uganda, Rwanda and Burundi are all landlocked nations, every drop of fuel and most freight coming into the country has to be trucked in from Mombasa and most of that comes through Busia. . . . This area of Kenya has some of the most intensively farmed land in East Africa. The whole landscape is divided into small plots with clusters of mud and thatch huts scattered among them. Here people live cheek-by-jowl with their crops and animals. It’s a recipe for diseases to jump from animals to people. Add strips of forested vegetation inhabited by a variety of monkeys and other native mammals and the chances of new diseases leaping into the human population goes up dramatically. We’re here to report on the work of a dedicated group trying to get a handle on exactly what diseases are in this chaotic system. It’s hard work, in one of the hotter areas of Kenya, and the study is spread over a huge area. . . .’

Adapting agriculture to improve human health–new ILRI policy brief

A sleeping sickness patient in Soroti, Uganda

A child with sleeping sickness undergoes lengthy recovery treatment at a sleeping sickness clinic in Soroti, Uganda (photo credit: ILRI).

John McDermott, a Canadian deputy director general for research at the International Livestock Research Institute (ILRI) and a veterinary epidemiologist by training, and Delia Grace, an Irish veterinary epidemiologist working in food safety and many other areas of livestock health, have written a new policy brief on agriculture-associated diseases.

This policy brief has recently been disseminated by McDermott and Grace at an international conference on the agriculture, nutrition and health interface in New Delhi and a conference on the ‘One Health’ approach to tackling human and animal health, held in Melbourne.

McDermott and Grace argue that the way we approach agriculture does not serve human interests as a whole. ‘In the past, agricultural research and development largely focused on improving the production, productivity and profitability of agricultural enterprises. The nutritional and other benefits of agriculture were not always optimized, while the negative impacts on health, well-being and the environment were often ignored. This was especially problematic for livestock systems, with especially complex negative and positive impacts on human health and well-being.’

They give as an example a side effect of agricultural intensification: disease. ‘Highly pathogenic avian influenza (HPAI) is a notorious example of a disease that was fostered by intensified agricultural production and spread through lengthened poultry value chains and the global movement of people and animals. Large-scale irrigation projects, designed to increase agriculture productivity, have created ecosystems conducive to schistosomiasis and Rift Valley fever.’

And the reason we fail to foresee the negative effects of some agricultural practices, they say, is because the responses to disease threats are often compartmentalized. ‘Instead of analysing the tradeoffs between agricultural benefits and risks, the agriculture sector focuses on productivity, while the health sector focuses on managing disease. A careful look at the epidemiology of diseases associated with agriculture, and past experience of control efforts, shows that successful management must be systems-based rather than sectorally designed.’

‘At least 61% of all human pathogens are zoonotic (transmissible between animals and people),’ they write, ‘and zoonoses make up 75% of emerging infectious diseases. A new disease emerges every four months; many are trivial, but HIV, SARS, and avian influenza illustrate the huge potential impacts. Zoonoses and zoonotic diseases recently emerged from animals are responsible for 7% of the total disease burden in least-developed countries.

‘As well as sickening and killing billions of people each year, these diseases damage economies, societies and environments. While there is no metric that captures the full cost of disease, assessments of specific disease outbreaks suggest the scale of potential impacts. . . .

‘. . . There are two broad scenarios that characterize poor countries. At one extreme are neglected areas that lack even the most basic services; in these “cold spots,” diseases persist that are controlled elsewhere, with strong links to poverty, malnutrition and powerlessness. At the other extreme are areas of rapid intensification, where new and often unexpected disease threats emerge in response to rapidly changing practices and interactions between people, animals and ecosystems. These areas are hot spots for the emergence of new diseases (of which 75% are zoonotic). They also are more vulnerable to food-borne disease, as agricultural supply chains diversify and outpace workable regulatory mechanisms.

‘. . . What cannot be measured cannot be effectively and efficiently managed. Addressing agriculture-associated disease requires assessing and prioritizing its impacts, by measuring not only the multiple burdens of disease but also the multiple costs and benefits of potential interventions—across health, agriculture and other sectors. . . .

‘But these assessment tools and results have rarely been integrated to yield a comprehensive assessment of the health, economic and environmental costs of a particular disease. . . .

‘The complexities of agriculture-associated diseases call for more integrated and comprehensive approaches to analyse and address them, as envisioned in One Health and Eco- Health perspectives . . . . These integrated approaches offer a broad framework for understanding and addressing complex disease: they bring together key elements of human, animal and ecosystem health; and they explicitly address the social, economic and political determinants of health. Both of these global approaches recognize agriculture- and ecosystem-based interventions as a key component of multi-disciplinary approaches for managing diseases. For example, food-borne disease requires management throughout the field-to-fork risk pathway. Zoonoses in particular cannot be controlled, in most cases, while disease remains in the animal reservoir. Similarly, agriculture practices that create health risks require farm-level intervention.

‘Systemic One Health and EcoHealth approaches require development and testing of methods, tools and approaches to better support management of the diseases associated with agriculture. The potential impacts justify the substantial investment required. . . .

‘As a basis for framing sound policies, information is needed on the multiple (that is, cross-sectoral) burdens of disease and the multiple costs and benefits of control, as well as the sustainability, feasibility and acceptability of control options. An example of cross-disciplinary research that effectively influenced policy is the case of smallholder dairy in Kenya. In the light of research by ILRI and partners, assessing both public health risks and poverty impacts of regulation, the health regulations requiring pasteurization of milk were reversed; the economic benefits of the change were later estimated at USD26 million per year. This positive change required new collaboration between research, government and non-governmental organizations and the private sector, as well as new ways of working . . . .

‘Many agriculture-associated diseases are characterized by complexity, uncertainty and high-potential impact. They call for both analytic thinking, to break problems into manageable components that can be tackled over time, and holistic thinking, to recognize patterns and wider implications as well as potential benefits.

‘The analytic approach is illustrated in the new decision-support tool developed to address Rift Valley fever in Kenya. In savannah areas of East Africa, climate events trigger a cascade of changes in environment and vectors, causing outbreaks of Rift Valley fever among livestock and (ultimately) humans. Improving information on step-wise events can lead to better decisions about whether, when, where and how to institute control . . . .

‘An example of holistic thinking is pattern recognition applied to disease dynamics, recognizing that emerging diseases have multiple drivers. A synoptic view of apparently unrelated health threats—the unexpected establishment of chikungunya fever in northern Italy, the sudden appearance of West Nile virus in North America, the increasing frequency of Rift Valley fever epidemics in the Arabian Peninsula, and the emergence of bluetongue virus in northern Europe—strengthens the suspicion that a warming climate is driving disease expansion generally.

‘Complex problems often benefit from a synergy of various areas of expertise and approaches. . . . Complex problems also require a longer term view, informed by the understanding that short-term solutions can have unintended effects that lead to long-term problems—as in the case of agricultural intensification fostering health threats. . . .

‘New, integrative ways of working on complex problems, such as One Health and EcoHealth, require new institutional arrangements. The agriculture, environment and health sectors are not designed to promote integrated, multi-disciplinary approaches to complex, cross-sectoral problems. But many exciting initiatives provide examples of successful institutional collaboration. . . .

‘Agriculture and health are intimately linked. Many diseases have agricultural roots—food-borne diseases, water-associated diseases, many zoonoses, most emerging infectious diseases, and occupational diseases associated with agrifood chains. These diseases create an especially heavy burden for poor countries, with far-reaching impacts. This brief views agriculture-associated disease as the dimension of public health shaped by the interaction between humans, animals and agro- ecoystems. This conceptual approach presents new opportunities for shaping agriculture to improve health outcomes, in both the short and long terms.

‘Understanding the multiple burdens of disease is a first step in its rational management. As agriculture-associated diseases occur at the interface of human health, animal health, agriculture and ecosystems, addressing them often requires systems-based thinking and multi-disciplinary approaches. These approaches, in turn, require new ways of working and institutional arrangements. Several promising initiatives demonstrate convincing benefits of new ways of working across disciplines, despite the considerable barriers to cooperation.’

Read the whole ILRI policy brief by John McDermott and Delia Grace: Agriculture-associated diseases: Adapting agriculture to improve human health, February 2011.

Livestock boom risks aggravating animal ‘plagues,’ poses growing threat to food security and health of world’s poor

Shepherd in Rajasthan, India

Research released at conference calls for thinking through the health impacts of agricultural intensification to control epidemics that are decimating herds and endangering humans (Picture credit: ILRI/Mann).

Increasing numbers of domestic livestock and more resource-intensive production methods are encouraging animal epidemics around the world, a problem that is particularly acute in developing countries, where livestock diseases present a growing threat to the food security of already vulnerable populations, according to new assessments reported today at the International Conference on Leveraging Agriculture for Improving Nutrition & Health in New Delhi, India.

‘Wealthy countries are effectively dealing with livestock diseases, but in Africa and Asia, the capacity of veterinary services to track and control outbreaks is lagging dangerously behind livestock intensification,’ said John McDermott, deputy director general for research at the International Livestock Research Institute (ILRI), which spearheaded the work. ‘This lack of capacity is particularly dangerous because many poor people in the world still rely on farm animals to feed their families, while rising demand for meat, milk and eggs among urban consumers in the developing world is fueling a rapid intensification of livestock production.’

The global conference (, organized by the International Food Policy Research Institute, brings together leading agriculture, nutrition and health experts to assess ways to increase agriculture’s contribution to better nutrition and health for the world’s most vulnerable people.

The new assessments from ILRI spell out how livestock diseases present ‘double trouble’ in poor countries. First, livestock diseases imperil food security in the developing world (where some 700 million people keep farm animals and up to 40 percent of household income depends on them) by reducing the availability of a critical source of protein. Second, animal diseases also threaten human health directly when viruses such as the bird flu (H5N1), SARS and Nipah viruses ‘jump’ from their livestock hosts into human populations.

McDermott is a co-author with Delia Grace, a veterinary and food safety researcher at ILRI, of a chapter on livestock epidemics in a new book called ‘Handbook of Hazards and Disaster Risk Reduction.’ This chapter focuses on animal plagues that primarily affect livestock operations—as opposed to human populations—and that are particularly devastating in the developing world.

‘In the poorest regions of the world, livestock plagues that were better controlled in the past are regaining ground,’ they warn, with ‘lethal and devastating impacts’ on livestock and the farmers and traders that depend on them. These ‘population-decimating plagues’ include diseases that kill both people and their animals and destroy livelihoods.

Livestock-specific diseases include contagious bovine ‘lung plague’ of cattle, buffalo and yaks, peste des petits ruminants (an acute respiratory ailment of goats and sheep), swine fever (‘hog cholera’) and Newcastle disease (a highly infectious disease of domestic poultry and wild birds). The world’s livestock plagues also include avian influenza (bird flu) and other ‘zoonotic’ diseases, which, being transmissible between animals and people, directly threaten human as well as animal health.

McDermott and Grace warn that new trends, including rapid urbanization and climate change, could act as ‘wild cards,’ altering the present distribution of diseases, sometimes ‘dramatically for the worse.’ The authors say developing countries need to speed up their testing and adoption of new approaches, appropriate for their development context, to detect and then to stop or contain livestock epidemics before they become widespread.

In a separate but related policy analysis to be presented at the New Delhi conference, McDermott and Grace focus on links between agricultural intensification and the spread of zoonotic diseases. The researchers warn of a dangerous disconnect: the agricultural intensification now being pursued in the developing world, they say, is typically focused on increasing food production and profitability, while potential effects on human health remain ‘largely ignored.’

A remarkable 61 percent of all human pathogens, and 75 percent of new human pathogens, are transmitted by animals, and some of the most lethal bugs affecting humans originate in our domesticated animals. Notable examples of zoonotic diseases include avian influenza, whose spread was primarily caused by domesticated birds; and the Nipah virus infection, which causes influenza-like symptoms, often followed by inflammation of the brain and death, and which spilled over to people from pigs kept in greater densities by smallholders.

The spread and subsequent establishment of avian influenza in previously disease-free countries, such as Indonesia, was a classic example, McDermott and Grace say, of the risks posed by high-density chicken and duck operations and long poultry ‘value chains,’ as well as the rapid global movement of both people and livestock. In addition, large-scale irrigation aimed at boosting agricultural productivity, they say, has created conditions that facilitate the establishment of the Rift Valley fever virus in new regions, with occasional outbreaks killing hundreds of people along with thousands of animals.

The economic impacts of such zoonotic diseases are enormous. The World Bank estimates that if avian influenza becomes transmissible from human to human, the potential cost of a resulting pandemic could be USD3 trillion. Rich countries are better equipped than poor countries to cope with new diseases—and they are investing heavily in global surveillance and risk reduction activities—but no one is spared the threat as growing numbers of livestock and easy movement across borders increase the chances of global pandemics.

But while absolute economic losses from livestock diseases are greater in rich countries, the impact on the health and livelihoods of people is worse in poor countries. McDermott and Grace point out, for example, that zoonotic diseases and food-borne illnesses associated with livestock account for at least 16 percent of the infectious disease burden in low-income countries, compared to just 4 percent in high-income nations.

Yet despite the great threats posed by livestock diseases, McDermott and Grace see a need for a more intelligent response to outbreaks that considers the local disease context as well as the livelihoods of people. They observe that ‘while few argue that disease control is a bad thing, recent experiences remind us that, if livestock epidemics have negative impacts, so too can the actions taken to control or prevent them.’

An exclusive focus on avian influenza preparedness activities in Africa relative to other more important disease concerns, they point out, invested scarce financial resources to focus on a disease that, due to a low-density of chicken operations and scarcity of domestic ducks, is unlikely to do great damage to much of the continent. And they argue that a wholesale slaughter of pigs in Cairo instituted after an outbreak of H1N1 was ‘costly and epidemiologically pointless’ because the disease was already being spread ‘by human-to-human transmission.’

McDermott and Grace conclude that to build surveillance systems able to detect animal disease outbreaks in their earliest stages, developing countries will need to work across sectors, integrating veterinary, medical, and environmental expertise in ‘one-health’ approaches to assessing, prioritizing and managing the risks posed by livestock diseases.

More information on why animals matter to health and nutrition: and