“green revolution” in the Cerrado, Brazil’s vast savanna lands lying south of the Amazon rain forest. Through a combination of soil improvement, integration of crop and livestock farming, no-till agriculture, and genetic improvement of forage grasses, soybean and livestock, Embrapa has, in the span of 30 years, transformed Brazil from a net food importer to one of the world’s bread-baskets, the largest exporter of beef and poultry, and the second largest exporter of soybean in the world (Economist, 2010). This model could be adapted to the savanna lands of Africa and Asia.
Food supplies must be capable of withstanding shocks from weather, economic crises, crop pests, and livestock diseases. Food systems in developed countries are generally resilient while those in developing countries are not (FAO, 2011; p. 4 and pp. 88-91). As the numbers of livestock and poultry produced in the developing world has increased, world trade in foods of animal origin has also expanded significantly, increasing the opportunity for infectious agents to gain a foothold in food systems. As a result, new and re-emerging infectious diseases have appeared almost on an annual basis for the past two decades. Seventy percent are zoonotic and most have come from reservoirs of infection in wildlife. The spread of H5N1 avian influenza, West Nile virus, Severe Acute Respiratory Syndrome (SARS), and Monkey pox provide examples. Collectively, the epidemics they incited drew attention to the lack of coordination between human and veterinary public health services. It was this omission that gave rise to the One Health Initiative now championed by AVMA.
In addition, climate change is altering the range of pathogens, especially when they or their vectors depend upon warm temperatures and high humidity. Bluetongue virus is an example; the virus affects ruminants, especially sheep. In the past ten years bluetongue has spread from its traditional range in North Africa to most of Europe causing massive losses in sheep and disrupting trade (www.fao.org/docs/eims/upload/213041/EW_europe_sept06.pdf).
Extensive systems of livestock farming in many parts of the world have intruded increasingly into wildlife habitat, crowding and stressing wildlife and changing the dynamics of disease transmission. As a result, infectious diseases of wildlife, many of which were previously unknown, have been transmitted to livestock and people. Nipah virus, for example, spread in Malaysia from a reservoir of infection in fruit bats to swine and then to people where it was associated with high fatality rates. As a result, the swine industry suffered high losses and has been severely restricted in that country. There is every prospect that this pattern of disease emergence will continue and it is the task of the veterinary profession worldwide to work with the medical profession, environmental scientists, wildlife biologists, and others to provide surveillance of wildlife health and monitor the emergence of new infections that may threaten human health and the resilience of the food supply.