ILRI news

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: http://rvfworkshop2011.wordpress.com

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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.

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Cow suffering from trypanosomiasis (photo credit: ILRI/Elsworth).

An international research team using a new combination of approaches has found two genes that may prove of vital importance to the lives and livelihoods of millions of farmers in a tsetse fly-plagued swathe of Africa the size of the United States. The team’s results were published today in the Proceedings of the National Academy of Sciences (PNAS).

The research, aimed at finding the biological keys to protection from a single-celled trypanosome parasite that causes both African sleeping sickness in people and a wasting disease in cattle, brought together a range of high-tech tools and field observations to address a critical affliction of some of the world’s poorest people.

With increased surveillance and control, sleeping sickness infections in people have dropped ten-fold in the last 13 years, from an estimated 300,000 cases a year in 1998 to some 30,000 in 2009, with the disease eventually killing more than half of those infected. Although best known for causing human sleeping sickness, the trypanosome parasite’s most devastating blow to human welfare comes in an animal form, with sick, unproductive cattle costing mixed crop-livestock farmers and livestock herders huge losses and opportunities. The annual economic impact of ‘nagana,’ a common name in Africa for the form of the disease that affects cattle (officially known as African animal trypanosomiasis), has been estimated at US$4–5 billion.

In a vast tsetse belt across Africa, stretching from Senegal on the west coast to Tanzania on the east coast, and from Chad in the north to Zimbabwe in the south, the disease each year renders millions of cattle too weak to plow land or to haul loads, and too sickly to give milk or to breed, before finally killing off most of those infected. This means that in much of Africa, where tractors and commercial fertilizers are scarce and prohibitively expensive, cattle are largely unavailable for tilling and fertilizing croplands or for producing milk and meat for families. The tsetse fly and the disease it transmits are thus responsible for millions of farmers having to till their croplands by hand rather than by animal-drawn plow.

‘The two genes discovered in this research could provide a way for cattle breeders to identify the animals that are best at resisting disease when infected with trypanosome parasites, which are transmitted to animals and people by the bite of infected tsetse flies,’ said senior author Steve Kemp, a geneticist on joint appointment with the Nairobi-based International Livestock Research Institute (ILRI) and the University of Liverpool.

This genetics of disease resistance research was led by scientists from ILRI in Africa and from the UK universities of Liverpool, Manchester and Edinburgh, and involved researchers from other institutions in Britain, Ireland and South Korea.

The researchers drew on the fact that while the humped cattle breeds characteristic of much of Africa are susceptible to disease-causing trypanosome parasites, a humpless West African breed, called the N’Dama, is not seriously affected by the disease. Having been domesticated in Africa some 8,000 or more years ago, this most ancient of African breeds has had time to evolve resistance to the parasites. This makes the N’Dama a valued animal in Africa’s endemic regions. On the other hand, N’Dama cattle tend to be smaller, to produce less milk, and to be less docile than their bigger, humped cousins.

African agriculturalists of all kinds would like to see the N’Dama’s inherent disease resistance transferred to these other more productive breeds, but this is difficult without precise knowledge of the genes responsible for disease resistance in the N’Dama. Finding these genes has been the ‘Holy Grail’ of a group of international livestock geneticists for more than two decades, but the genetic and other biological pathways that control bovine disease resistance are complex and have proven difficult to determine.

The PNAS paper is thus a landmark piece of research in this field. The international and inter-institutional team that made this breakthrough did so by combining a range of genetic approaches, which until now have largely been used separately.

‘This may be the first example of scientists bringing together different ways of getting to the bottom of the genetics of a very complex trait,’ said Kemp. ‘Combined, the data were like a Venn diagram overlaying different sets of evidence. It was the overlap that interested us.’

They used these genetic approaches to distinguish differences between the ‘trypano-tolerant’ (humpless) N’Dama, which come from West Africa, and ‘trypano-susceptible’ (humped) Boran cattle, which come from Kenya, in East Africa. The scientists first identified the broad regions of their genomes controlling their different responses to infection with trypanosome parasites, but this was insufficient to identify the specific genes controlling resistance to the disease. So the scientists began adding layers of information obtained from other approaches. They sequenced genes from these regions to look for differences in those sequences between the two breeds.

The team at Edinburgh conducted gene expression analyses to investigate any differences in genetic activity in the tissues of the two cattle breeds after sets of animals of both breeds were experimentally infected with the parasites. Then, the ILRI group tested selected genes in the lab. Finally, they looked at the genetics of cattle populations from all over Africa.

Analyzing the vast datasets created in this research presented significant computational challenges. Andy Brass and his team in the School of Computer Science at the University of Manchester managed to capture, integrate and analyze the highly complex set of biological data by using workflow software called ‘Taverna,’ which was developed as part of a UK e-Science initiative by Manchester computer scientist Carole Goble and her ‘myGrid’ team.

‘The Taverna workflows we developed are capable of analyzing huge amounts of biological data quickly and accurately,’ said Brass. ‘Taverna’s infrastructure enabled us to develop the systematic analysis pipelines we required and to rapidly evolve the analysis as new data came into the project. We’re sharing these workflows so they can be re-used by other researchers looking at different disease models. This breakthrough demonstrates the real-life benefits of computer science and how a problem costing many lives can be tackled using pioneering E-Science systems.’

To bolster the findings, population geneticists from ILRI and the University of Dublin examined bovine genetic sequences for clues about the history of the different breeds. Their evidence confirmed that the two genes identified by the ILRI-Liverpool-Manchester groups were likely to have evolved in response to the presence of trypanosome parasites.

‘We believe the reason the N’Dama do not fall sick when infected with trypanosome parasites is that these animals, unlike others, have evolved ways to control the infection without mounting a runaway immune response that ends up damaging them,’ said lead author Harry Noyes, of the University of Liverpool. ‘Many human infections trigger similarly self-destructive immune responses, and our observations may point to ways of reducing such damage in people as well as livestock.’

This paper, said Kemp, in addition to advancing our understanding of the cascade of genes that allow Africa’s N’Dama cattle to fight animal trypanosomiasis, reaffirms the importance of maintaining as many of Africa’s indigenous animal breeds (as well as plant/crop varieties) as possible. The N’Dama’s disease resistance to trypanosome parasites is an example of a genetic trait that, while not yet fully understood, is clearly of vital importance to the continent’s future food security. But the continued existence of the N’Dama, like that of other native ‘niche’ African livestock breeds, remains under threat.

With this new knowledge of the genes controlling resistance to trypanosomiasis in the N’Dama, breeders could screen African cattle to identify animals with relatively high levels of disease resistance and furthermore incorporate the genetic markers for disease resistance with markers for other important traits, such as high productivity and drought tolerance, for improved breeding programs generally.

If further research confirms the significance of these genes in disease resistance, a conventional breeding program could develop a small breeding herd of disease-resistant cattle in 10–15 years, which could then be used over the next several decades to populate Africa’s different regions with animals most suited to those regions. Using genetic engineering techniques to achieve the same disease-resistant breeding herd, an approach still in its early days, could perhaps be done in four or five years, Kemp said. Once again, it would be several decades before such disease-resistant animals could be made available to most smallholder farmers and herders on the continent.

‘So it’s time we got started,’ said Kemp.

###

See this news and related background material at ILRI’s online press room.

The International Livestock Research Institute (www.ilri.org) works with partners worldwide to help poor people keep their farm animals alive and productive, increase and sustain their livestock and farm productivity, and find profitable markets for their animal products. ILRI’s headquarters are in Nairobi, Kenya; we have a principal campus in Addis Ababa, Ethiopia, and 13 offices in other regions of Africa and Asia. ILRI is part of the Consultative Group on International Agricultural Research (www.cgiar.org), which works to reduce hunger, poverty, illness and environmental degradation in developing countries by generating and sharing relevant agricultural knowledge, technologies and policies. This research is focused on development, conducted by a Consortium (http://consortium.cgiar.org) of 15 CGIAR centres working with hundreds of partners worldwide, and supported by a multi-donor Fund (www.cgiarfund.org).

The University of Liverpool (www.liv.ac.uk) is a member of the Russell Group of leading research-intensive institutions in the UK. It attracts collaborative and contract research commissions from a wide range of national and international organizations valued at more than £110 million annually.

The University of Manchester (www.manchester.ac.uk), also a member of the Russell Group, is the largest single-site university in the UK. It has 22 academic schools and hundreds of specialist research groups undertaking pioneering multi-disciplinary teaching and research of worldwide significance. According to the results of the 2008 Research Assessment Exercise, the University of Manchester is now one of the country’s major research universities, rated third in the UK in terms of ‘research power’. The university has an annual income of £684 million and attracted £253 million in external research funding in 2007/08.

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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’.

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On the last day (23 March 2011) of a ‘Future of Pastoralism in Africa’ Conference, organized by the Future Agricultures Consortium and the Feinstein International Center at Tufts University and held in Addis Ababa, Ethiopia, at the International Livestock Research Institute (ILRI), pastoralist experts took the conference participants through timelines that they had drawn up for selected pastoralist areas.

These hand-drawn timelines—with their famous place names and (in)famous droughts, wars and other major events variously, simply and affectingly sketched lightly on flipchart papers pasted to the walls of the conference hall—must have evoked memories, some of them heart-breaking, all of them heartfelt, in all but the youngest academic in the room. This was Africa’s pastoralist past—laid out in its crudest essentials on linear temporal bars punctuated by shorthand notes denoting big, often cataclysmic, events. This was an exercise meant to make room for rethinking the future of African pastoralism.

Examples of the kinds of statements made about the timelines (their baldness often matching the events they described) by the pastoralist ‘gurus’ who stood, one by one, to highlight a handful of major events depicted in each, follow.

Pastoralist Timelines

Niger Delta
‘A Tuareg rebellion arising in colonial times continues to this day. . . . Conflicts are a worse threat than climate change.’

Afar/Middle Awash
‘Critical dry-season grazing lands have been completely taken up by state farms. . . . More than 90,000 hectares of grazing land in Afar has been converted to sugar cane. . . . A 1973/4 drought is called the “gun drought” because the massive stock deaths led to massive sales of guns and other household assets to buy food. . . . Since a 1970s drought, people have begun keeping more goats than camels and cattle, and sugar cane is now taking over.’

Southern Somalia/Northeastern Kenya
‘The 1891 rinderpest calamity started the rural-to-urban migration. . . . Shifta conflicts in the 1960s began to isolate and stigmatize the area. . . . An outbreak of Rift Valley fever in the 1990s crushed the livestock trade. . . . The economic vibrancy in this stateless region outstrips its politics. . . . There is an on-going and robust cross-border boom in livestock and other trade. . . . Garissa is the fastest-growing town in Kenya; livestock remain critically important there. . . . The whole area is a kind of duty-free zone for electronics and other goods. . . . Piracy is a kind of livelihood diversification into the sea.’

Northern Kenya
‘Boundaries were first fixed and herding ranges squeezed in the colonial era. . . . In the post-colonial era, 1960–70, shifta started as legitimate rebels before becoming, and being seen as, bandits. . . . Starting in the 1990s, non-governmental organizations set up permanent offices, around which towns began to grow up. . . . A paved road built from Isiolo to Moyale will drive some pastoralists further away. . . . Land insecurity remains the biggest problem. . . . Roads and education bring with them new opportunities. . . . There is already much anticipation (and business deals being made) about the pipeline and railroad being planned from Lamu through Isiolo to Sudan. . . . Those who have resources have taken over the cattle economy of the area.’

Darfur/Sudan
‘In some areas and periods, there are no droughts because there are no rains at all. . . . Long-term marginalization and militarization have both been rapidly accelerating in recent years. . . . The future looks bleak. . . . The only good news is that there is widespread acknowledgement that international peace processes have failed.’

Southern Kenya/Maasai
‘Considerable inter-Maasai conflicts occurred from 1850 to 1900. . . . Early on, the Maasai ceded much of the Rift Valley to the colonialists. . . . In the 1940s, the colonialists created sectional divisions that remain problematical today. . . . The formation of group ranches led to catastrophic land losses. . . . Droughts of 1984, 1997/8, 2000, 2005, 2008/9; the last affected all areas, with no one escaping. . . . Major non-drought events include the 1945 establishment of national parks and the 1980s establishment of group ranches. . . . Since the 1990s, Christianity has swept across Maasailand, bringing with it great changes.’

Northern Tanzania/Maasailand
‘Kenya and Tanzania took very different paths regarding land and ethnicity. . . . Security of land and resources will be critical over next five years.’

Uganda/Karamajong
‘From colonial times to today, the Karamajong herders are not allowed to move. . . . A challenging national policy environment in Uganda makes promoting pastoralist livelihoods in Karamoja difficult.’

Southern Ethiopia/Borana
‘The 1972 and 1984 droughts were key events. . . . Education and services have both been improving in the region since 1991.’

Timeline keyword commonalities
Conflicts, diseases, droughts, geopolitical influences, land and land-use issues, national policies.

Keywords about the future of pastoralism
International issues, mobile phones, political representation, small towns, terrorism (and its impacts on aid).

Summing Up the Conference
After the timelines were described, some participants were asked to sum up the conference. The following are some of the things they said.

Dorothy Hodgson, Rutgers University, USA
‘Is there really such a thing as “pastoralist systems”? . . . Are we talking about pastoralism as a livelihood or as an identity? . . . Some are saying that pastoral women will drive pastoral futures. . . . We have to stop adding gender as a footnote. . . . It’s time to mainstream gender into pastoralist issues instead of “siloing” gender work’.

Peter Little, Emory University, USA
‘Population matters, politics matter, education matters to the future of pastoralism. . . . Diversification of pastoral livelihoods matter—especially as key resources are rapidly being lost. . . .Ecology matters as pastoral orbits become increasingly restricted. . . . And language matters—we should keep the word “innovation”, for example, about innovations.’

Orto Tumal, Pastoralist Shade Initiative, Kenya
‘Our future challenges are great. . . . We will, and must, march on.’

Paul Goldsmith, Develop Management Policy Forum, Kenya
‘Pastoralism has produced some very seductive literature.’

Luka Deng, Government of Sudan
‘There is a huge amount of information on pastoralists, but the real question is about what to do with it.’

Acknowledgements
Two of the conference organizers then closed the proceedings by making some acknowledgements, of which the following were included.

Andy Catley, Tufts University
‘In the early 1980s, pastoral groups were weak and arguments for pastoral rights appeared nostalgic in tone and character. . . . A tremendous intellectual contribution to pastoralism in the years since has helped to transform pastoralist discourse at all levels. . . .  Some of the “masters” of this discourse are here in this room today. . . . Stephen Sandford (private), Jeremy Swift (freelance), Ian Scoones (Future Agricultures Consortium) and Roy Behnke (Odessa Centre) have altered the intellectual foundations of our understanding of pastoralism. . . .

‘The central importance of livestock disease, particularly the great rinderpest epidemic in East Africa at the turn of the 20th century, was mentioned by several of our timeline developers. . . . The global eradication of rinderpest was announced earlier this year. . . . Three of those who contributed significantly to this great achievement (only the human disease smallpox has been similarly eradicated from the face of the earth) are in this room and I take the privilege of acknowledging them now: Solomom Hailemarium, African Union; Darlington Akabwai, Tufts University; and Berhanu Admassu, Tufts University.’

Ian Scoones, Future Agricultures Consortium
‘As we have heard this week, there is not one but multiple futures of pastoralism in Africa. . . . We have a new generation of African scholars contributing to African pastoralism. . . . We have an extraordinary body of scholarship now coming from this new generation. . . .’

See previous postings on the ILRI News Blog:

The future of pastoralism in Africa debated in Addis: Irreversible decline or vibrant future?, 21 March 2011.

Climate change impacts on pastoralists in the Horn: Transforming the ‘crisis narrative’, 22 March 2011.

The case for index-based livestock insurance and cash payments for northern Kenya’s pastoralists, 23 March 2011

Or visit the Future Agricultures Consortium website conference page or blog.

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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, 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.

NARRATION
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.

NARRATION
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.

NARRATION
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.

NARRATION
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.

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

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.

NARRATION
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.

NARRATION
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.

NARRATION
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.

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).

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

NARRATION
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.

NARRATION
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.

NARRATION
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.

NARRATION
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. . . .’

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A dairy cow looks out from her stall in central Malawi. Can such ubiquitous backyard livestock farming in the developing world feed the growing world? (picture credit: ILRI/Mann).

A special report on feeding the world, ‘The 9-billion people question,’ appears in this week’s issue of the Economist, as the world continues to grapple with a global food crisis. The author is the Economist‘s globalization editor, John Parker. In an article titled ‘Doing more with less’, Parker argues that ‘the only reliable way to produce more food is to use better technology.’

The world has three main ways to produce more food for our growing populations, he states, and we’ll need new technology for each. The three ways are better seeds, more productive livestock systems and advanced use of plant genetics, including genetic modification.

Parker gives examples of how ‘it is possible to grow more food, more efficiently, on both a regional and a national scale.’ ‘But,’ he asks, ‘can it be done on a global scale . . . to feed 9 billion people? If so, how?’

‘The main gains will have to come in three ways,’ Parker writes: ‘from narrowing the gap between the worst and best producers; from spreading the so-called “livestock revolution”; and—above all—from taking advantage of new plant technologies.’

(1) Regarding the first way, Parker says better technology is already closing the gap between best and worst producers in comparable environments.

(2) Regarding the second way, Parker writes: ‘The second main source of growth will consist of spreading a tried and tested success: the “livestock revolution”. This consists of switching from traditional, open-air methods of animal husbandry, in which chickens and pigs scratch and root around the farm, eating insects, scraps and all sorts of organic waste, to closed “battery” systems, in which animals are confined to cages and have their diet, health and movement rigorously controlled. This entails huge losses in animal welfare, and European consumers are reacting against the system. But there are also gains in productivity and sometimes even in welfare, by reducing losses from diseases and predators that in traditional systems can be distressingly high.

‘Improving livestock farming is important because of meat’s growing share in the world’s diet. Meat consumption in China more than doubled in 1980-2005, to 50kg a year per person. Between now and 2050, meat’s share of calories will rise from 7% to 9%, says the FAO; the share of dairy produce and eggs will rise more.

‘Livestock matters for many reasons. It provides financial security in poor countries, where herds are often a family’s savings. It can affect people’s health: new infectious diseases are appearing at the rate of three or four a year, and three-quarters of them can be traced to animals, domestic and wild. Avian flu is just one example. Livestock also plays a part in global warming. Much of the methane in the atmosphere—one of the worst greenhouse gases—comes from cattle belching.

‘Since the 1980s livestock production has far outstripped that of cereals. World meat output more than doubled between 1980 and 2007. Production of eggs rose from 27m tonnes to 68m over the same period. Some countries have done better still. India has the world’s largest dairy herd. Its milk production trebled, to 103m tonnes, over a period when global milk output increased by half. Brazil increased its production of chickens fivefold in 1987-2007 to become the world’s largest exporter. Most spectacularly, China raised its output of both eggs and milk tenfold.

‘For sheer efficiency, there is little question that battery systems do a better job than traditional methods. A free-range hen scratching around might lay one or two eggs a week. Feeding her costs nothing, giving a net gain of 50-100 eggs a year. A battery chicken will lay six eggs a week. She might cost the equivalent of 150 eggs to feed, producing an annual net gain of 150 eggs. And selective breeding has made her more economic to keep. Battery chickens used to need 4kg of feed for 1kg of eggs; now they need only 2kg.

‘Moreover, it is almost impossible to scale up a farmyard operation: there are only so many insects to eat, and so many hens one family can look after. And to breed the most productive hens which convert their feed most efficiently into eggs and are most resistant to disease, you need large flocks.

‘So there are two reasons for thinking that the livestock revolution will continue. One is that some countries still lag behind. An example, surprisingly, is Brazil, which has just one head of cattle per hectare—an unusually low number even for a country with so much land. Roberto Giannetti da Fonseca, of the São Paulo industry federation, says Brazil should be able at least to double that number—which could mean either doubling beef production or using half the area to produce the same amount.

‘Carlos Sere of the International Livestock Research Institute thinks traditional systems could borrow some of the methods of closed battery-farm systems—notably better feeding (giving a small amount of animal feed makes a big difference to the weight of range-land cattle) and the introduction of new breeds for better yields (as Kabiyet did by switching from longhorn to Holstein cattle).

‘The second reason for expecting further gains is that recent genetic analysis could improve breeding dramatically. About a third of the livestock revolution has come about through selecting and breeding the best animals. Another third comes from improved feeding and the remainder from better disease control. In the 1940s and 1950s breeding relied on the careful recording of every animal in the herd or flock; in the 1970s on artificial insemination by the best sires; and in the 1980s on embryo transfers from the best females into ordinary breeding animals.

‘New genetic analysis now promises to bring in another stage, says the FAO’s Henning Steinfeld. It allows breeders to select traits more precisely and thus speeds up breeding by reducing generational intervals: if you know which genetic traits an animal has, there is no need to wait several generations to see how things turn out.

‘This will not happen everywhere. Europeans and—to some extent—Americans are increasingly influenced by welfare concerns. They jib at confining animals. The European Union has banned certain kinds of cages, and California is following suit. But, so far, people in emerging markets, where demand for meat and animal products is growing fast, are less concerned about such things, so the next stage of the livestock revolution will mainly be concentrated there.’

(3) Regarding the third way—making better use of plant genetics, Parker argues that ‘the change likely to generate the biggest yield gains in the food business—perhaps 1.5-2% a year—is the development of “marker-assisted breeding”—in other words, genetic marking and selection in plants, which includes genetically modifying them but also involves a range of other techniques. This is the third and most important source of growth.’

Read the whole special report in the Economist: The 9 billion-people question, 24 February 2011.

Read the whole article in the Economist: Doing more with less, 24 February 2011.

Listen to John Parker interviewed on this subject: A special report on food, 24 February 2011.

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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.

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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 (http://2020conference.ifpri.info), 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: http://mahider.ilri.org/handle/10568/3152 and http://mahider.ilri.org/handle/10568/3149

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What happens when farming families in poor countries lose their most important possessions?

Through the words of one African family, we learn in this short (4 minutes, 50 seconds) film, 'Why livestock?' from the International Livestock Research Institute (ILRI) how livestock losses change lives.

By providing nourishing food, regular income, traction for ploughing, and manure to fertilize their croplands, farm animals are the foundation of some one billion lives and livelihoods.

‘Life is hard for us now without livestock,’ says this family.

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