The World Food Prize - often described as the Nobel prize for food research - has been awarded to a scientist whose work has helped save farmers worldwide from starvation and economic ruin. British veterinary researcher Walter Plowright developed a vaccine against rinderpest, the most lethal of cattle diseases.
Rinderpest is highly infectious and is spread by direct contact and by drinking-water that has been infected by the dung of sick animals. Infected cattle develop a high fever; red patches with discharge from around the eyes, nose and mouth; frothy saliva from the mouth; constipation followed by diarrhoea. It takes just a few days for a sick animal to die. An outbreak of this viral disease can wipe out whole herds.
An epidemic in the 1890s killed 80 to 90 percent of all cattle in sub-Saharan Africa. More recently, another rinderpest outbreak that raged across much of Africa in 1982-84 is estimated to have cost at least US$500 million.
Animal and human welfare
Thanks to Plowright's work, this disease is now largely under control and the Food and Agriculture Organization of the United Nations (FAO) is aiming to eradicate it entirely by 2010.
Dr Plowright began his work on rinderpest in Kenya in the 1950s and his achievement was to produce a vaccine that was cheap, effective and could survive in the tropical conditions where rinderpest was rife. The vaccine has been so successful that rinderpest is now confined to isolated pockets in sub-Saharan Africa, parts of Pakistan and the Near East. But FAO is confident that, with the help of the Plowright vaccine, it will be the first animal disease to be wiped off the face of our planet.
The World Food Prize was first awarded in 1987 and recognizes people who have advanced human development by improving the quality, quantity or availability of food in the world. Past winners of the US$250 000 prize have included agriculturists and financiers, but this is the first time someone working in veterinary science has been honoured, thus recognizing the importance of animal health to human welfare.
It is said that humankind is the most destructive species the earth has ever known. True or not, it is a characterization that is perhaps better reserved for a notorious animal virus called rinderpest. Causing havoc since the time of the Roman Empire, rinderpest has destroyed countless millions of cattle, caused staggering economic losses, and has contributed to famine, social unrest and even war. Also known as cattle plague, just one outbreak of rinderpest during the 1980s in Nigeria was responsible for losses of more than US$2 billion. Add thousands of recorded outbreaks since AD 375 and the scale of devastation wrought by rinderpest becomes unimaginable.
But with the dawn of a new millennium, the scourge of rinderpest may finally be banished by its global eradication. This year's winner of the prestigious World Food Prize has spent many years of his professional life pursuing what has eluded researchers for more than 1 000 years, a universal vaccine to rid the world of rinderpest. Not only has this man succeeded where many failed, but his effective, safe and affordable vaccine has made possible the elimination of rinderpest from many regions of the developing world - particularly in Africa and Asia. His research has provided a practical means to remove a menace dating back 16 centuries. And for this incalculable contribution to world food security, Dr Walter Plowright, 76, has been named the 1999 recipient of the World Food Prize.
The economical, technical and humanitarian benefits derived from just under 40 years of use of the Plowright vaccine are immense. It has proved to be of extraordinary significance in ensuring the supply of high-protein food to poorer nations in Africa and Asia. The financial benefits of rinderpest control can be measured in terms of the value of additional production of milk, meat and hides as a result of reduced mortality in cattle. FAO estimates that the additional production in India alone from 1965 to 1998 amounted to US$289 billion. Corresponding estimates for Africa during the same period amounted to US$47 billion; and these are just two major examples. Billions of dollars have no doubt also been generated in other countries, such as Sri Lanka, Pakistan, Afghanistan, Iran and Turkey. The protection of cattle in sub-Saharan Africa, the Near East and Asia has brought vital security, leading to the following benefits:
- Preservation of both food and income streams for hundreds of thousands,
if not millions, of pastoral people and small farmers.
- Avoidance of famine caused by catastrophic cattle losses in rinderpest
epidemics.
- Reduced sociopolitical upheaval resulting from impoverishment of prime
food resources.
Sixteen centuries of devastation
More than 1 500 years ago rinderpest emerged to take its toll on humankind's domesticated animals. It is the only animal disease credited with changing the course of history. A fragile virus that is spread by contact and nearly always fatal to cattle and hoofed animals, rinderpest was first recognized as a distinct plague (the cattle plague) in AD 376-386.
During the following centuries, rinderpest ravaged livestock populations in Europe and Asia, occurring as a by-product of every major military campaign with extensive cattle movements. The disease brought disaster and famine that accompanied the fall of the Roman Empire, the conquest of Christian Europe by Charlemagne, the French Revolution, the impoverishment of Russia and the colonization of Africa. In the eighteenth century, 200 million cattle were killed in Western Europe alone. This devastation was one of the major factors leading to the founding of veterinary science - with the establishment of the first Veterinary School in Lyons, France, in 1762.
The disease was spread by the expansion of international cattle trade in the nineteenth century, by sea as well as by land. Hardly a continent or country has not been affected by rinderpest. While only one outbreak has been recorded in North and South America (in the 1920s), other areas of the world have been much more severely affected.
One particularly severe outbreak began in northeastern Africa in 1887 in what would later become Plowright's area of operation. The disease is said to have entered Africa at the Red Sea port of Massawa, spreading west to the Atlantic and south to the Cape. It is estimated that more than 90 percent of the cattle and game animals, particularly buffaloes, dedu, eland and wildswine, died of the disease. Pastoral tribes were devastated and those such as the Masai were so weakened as to change the balance of power for ever. In Europe and elsewhere, it became clear that livestock production and trade could only be safeguarded by controlling rinderpest. To this end, the International Office of Epizootics (OIE) was established in Paris in 1924, and FAO, which was established in 1945, also treated rinderpest as an initial priority in animal disease control.
Journey to Africa
Walter Plowright was born in 1923 in Lincolnshire on the east coast of England. His family were small farmers; his parents had five children and he was the second of three sons. He progressed through local schools, state and grammar, where he formed the ambition to become a veterinarian rather than remain on the farm. His father eventually accepted the break with tradition and he entered the Royal Veterinary College in London at the age of 17 in 1940.
After graduating in 1944, Plowright was commissioned in the Royal Army Veterinary Corps towards the end of the Second World War. His wartime postings sent him in 1945 to Kenya, a country for which he formed a deep affection. In 1948 he began two years as a junior lecturer at the Royal Veterinary College, London, but then decided to enter the Colonial Veterinary Service in Africa. He was posted to Kenya as a pathologist where he began to familiarize himself with a multiplicity of animal diseases, including rinderpest. From Kenya, Plowright went to Nigeria for a tour of 20 months before returning to the Muguga Laboratory of the East African Veterinary Research Organization, where he worked for more than 15 years. The development of cell-culture vaccine and its widespread application to field use all took place in the Muguga Laboratory, primarily in the years 1956 to 1970. While the World Food Prize acknowledges Plowright's work on rinderpest, he also made a significant contribution to research on a number of other animal diseases of viral origin. These included African swine fever, malignant catarrhal fever, other rinderpest-like diseases, ungulate poxviruses and herpesviruses.
THE WORLD FOOD PRIZEA prize for the worldThe World Food Prize is the foremost international award recognizing - regardless of race, religion, nationality or political beliefs - the achievements of individuals who have advanced human development by improving the quality, quantity or availability of food in the world. The prize recognizes contributions in any field involved in the world food supply - food and agricultural science and technology, manufacturing, marketing, nutrition, economics, political leadership and the social sciences. The World Food Prize emphasizes the importance of a nutritious and sustainable food supply for all people. By honouring those who have worked successfully towards this goal, The prize draws attention to what has been done to improve the world food supply and to what can be accomplished in the future. The laureate receives US$250 000 and a sculpture created by world-renowned designer Saul Bass. Why the World Food Prize was createdNorman E. Borlaug, winner of the Nobel Peace Prize in 1970 for his work in world agriculture, envisioned a prize that would honour those who have made significant and measurable contributions to improving the world's food supply. Beyond recognizing such people for their personal accomplishments, he saw the prize as a means of establishing role models who would inspire others. His vision was realized when the World Food Prize was created in 1986. The prize programmeThe World Food Prize is sponsored by businessman and philanthropist John Ruan and is administered by The World Food Prize Foundation in Des Moines, Iowa, United States. The foundation is guided by a Council of Advisors in the establishment of policy and in the annual review of the prize. Iowa State University College of Agriculture in Ames, Iowa, serves as secretariat for the prize. Each year, more than 4 000 institutions and organizations worldwide are invited to nominate laureate candidates. The secretariat reviews all nominations for appropriateness and completeness and forwards them to the Selection Committee, which decides on the candidate most worthy of the award according to the prize's objectives.
The Selection Committee is composed of nine distinguished individuals who
are experts in various aspects of nutrition and food production, processing
and distribution, including research, policy development and business management.
Members of the Selection Committee remain anonymous, with the exception of
the chairman, Norman Borlaug. |
Research and discovery
Plowright records that "in the early 1950s, when I first began working in Muguga on rinderpest, the general view was that a very satisfactory situation existed so far as the vaccines were concerned." In fact, they were far from perfect. They often induced fever, diarrhoea and relapse to other diseases in inoculated animals, and a mortality rate up to 2 to 5 percent was still regarded as acceptable. The difficulty was greatest in highly susceptible breeds, such as Ankole and Ndama.
The production and testing of the old vaccines was costly since it required use of animals - cattle, goats or rabbits - that are sometimes difficult to procure in developing countries. There were also difficulties in isolating the animals securely and determining whether or not experimental cattle or goats were immune, as a result of previous infection with the rinderpest virus.
Plowright quickly deduced that many of the problems in rinderpest research and control could be resolved by developing methods for growing viruses in monolayer cultures of cells on glass - methods already made available for research on poliomyelitis, varicella and measles viruses by the Harvard group, headed by John F. Enders, a Nobel Prize winner. While stationed in Vom, Nigeria, in 1955, Plowright made an attempt to culture rinderpest virus but had to terminate the work for lack of adequate facilities.
In 1956, on transfer to the Muguga Laboratory in Kenya, he began a series of studies on cell cultures that would change history; here the Plowright rinderpest vaccine became a reality. Often known as tissue culture rinderpest vaccine (TCRV), it provided a number of advantages. Animals of any age or breed and cattle in varying conditions of health, including pregnant cows, could be inoculated. The vaccine was genetically stable, produced no significant clinical reaction, was easily standardized, economical to produce and adequately stable when freeze-dried. Most important, inoculated cattle were immune for at least ten years, if not for life. A universal standard vaccine for the elimination of rinderpest, the lethal cattle plague, had arrived on the world scene.
Significance of achievement
The new vaccine offered new hope, particularly for nomadic pastoral peoples and small farmers in developing nations.
Although Western countries tend to regard cattle simply as a source of food, other cultures depend on cattle literally to sustain life itself. In many developing countries, particularly in Asia, cattle are also still used for traction, cultivation and even load carrying. For many people cattle are the only ready source of cash and in many parts of Africa, for example, cattle are indeed a measure of a person's wealth. Essentially, they provide a capital reserve for the family, their numbers being built up in good times and then consumed for celebrations or when crops are poor. They may be sold off or traded when a family faces major expenses, such as providing a marriage dowry.
The manure and urine, regarded as pollutants in developed countries, serve as vital fertilizers for crops or as fuel and building materials. Cattle, in turn, consume by-products of arable crops such as millet or maize that would ordinarily be waste. Vast areas of savannah grasslands or high-altitude pastures and steppes both in Africa and Asia can only support a nomadic pastoral system.
Cattle are a vital source of income for small rural farmers and the demand for cattle as food is increasing rapidly in developing countries, especially in urban areas where populations are growing dramatically. Between the early 1970s and the mid-1990s, meat consumption grew by over 70 million tonnes in developing countries. This "livestock revolution" can be expected to continue well into the new century.
The successful raising of cattle can increase and stabilize income and employment. Moreover, it can help to feed growing world populations, assuming that rinderpest can be conquered. It becomes obvious in such a scenario just how crucial and effective rinderpest vaccine is in today's world.
The next ten years
Thanks to the development of the Plowright vaccine, the world stands on the verge of total elimination of rinderpest. FAO officials report that the disease now persists only in parts of the Sudan, Somalia and Pakistan. Assuming that other areas do not become infected, FAO further predicts that it may cost as little as US$3 million to eradicate the virus completely.
In 1994, FAO initiated an international programme, the Global Rinderpest Eradication Programme (GREP), to coordinate final global eradication of rinderpest by the year 2010. It is the first priority of a wider programme, the Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases (EMPRES), which is intended to deploy resources quickly in disease control and has emerged as a good example of how countries and people can act together to control threats such as rinderpest and help secure the world food supply.
While rinderpest may be close to eradication, many other diseases continue to threaten the world's livestock. Although Plowright's work has brought one global menace, rinderpest, to its knees, there are dozens of other microbial pathogens to take its place. Fortunately, through Plowright's efforts, and the awareness generated by the World Food Prize, there will be scores of other researchers eager to follow his good work and take on the challenge.
[Ed. note: Walter Plowright was the keynote speaker at the 1998 EMPRES technical consultation on GREP where he presented a paper entitled, Global professional commitment to the success of the Global Rinderpest Eradication Programme. He was nominated by FAO for the World Food Prize.]
CURRICULUM VITAE
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