INTRODUCTION
The WHO definition of VPH is that component of public health activities devoted to the application of veterinary skills, veterinary knowledge and veterinary resources for the protection and improvement of human health. This definition implies in many ways an unrestricted assignment to the veterinary and para-veterinary professions. It is restrictive, however, because it implies application of veterinary knowledge and skills to protect and improve human health without acknowledging the coordinated effort necessary from all related disciplines in a rapidly changing environment to achieve this goal.
The environment is changing rapidly, but developing countries have not been able to respond with new structures and initiatives. Reports from developing countries on the status of VPH service delivery in 1991 compared to reports from the same countries in 1999 show insignificant changes to meet challenges identified more than a decade ago. After all these years, it appears that discussions to allocate institutional responsibility for the delivery of VPH services and to define their scope are still continuing. Several major animal disease incidents in the past decade have triggered this sensitivity: the BSE crisis in the United Kingdom and subsequent increased incidence of BSE in other European countries, the current FMD crisis in the United Kingdom and the rest of the world, food-borne disease incidents caused by salmonella and E. coli and deaths caused by major disease outbreaks such as Nipah virus in Malaysia, avian influenza in Hong Kong and RVF in East Africa.
Two diverging strata for VPH and food safety are emerging. The first comprises the rapidly intensifying livestock-production systems in urban and peri-urban areas. Intensifying systems occur in almost all regions of the developing world, particularly southeast and southern Asia, East and West Africa and the Andean region of Latin America. The second stratum is the traditional pastoral and agro-pastoral sector. Three crucial zoonotic disease and food safety issues present themselves:
There will be a dichotomy of issues and approaches in intensive versus traditional livestock systems, but the impact of zoonotic diseases and food-borne infections and intoxications on health and wellbeing will be greatest among the 800 million food-insecure livestock keepers, consumers, traders and labourers.
Innovative approaches will be required to address rapidly evolving VPH and food-safety environments in intensifying systems. Expected changes and trends include:
Intensified systems in developing countries will be responsible for supplying 60 percent of the world’s meat and 52 percent of its milk by 2020. This increasing proportion of livestock production will lead to pressure to modify OIE and World Trade Organization (WTO) regulations (see Chapter 5).
The proportion of livestock produced by traditional pastoralist and agro-pastoralist systems will decline. As a result, there are major risks that farmers and consumers in these systems will be forgotten or marginalized with regard to VPH and food-safety innovations and that the current impacts of classical zoonoses and food-borne infections such as anthrax will persist or even worsen.
CHANGING ECOLOGY AND LIVESTOCK PRODUCTION SYSTEMS ASSOCIATED WITH ZOONOTIC AND FOOD-BORNE INFECTIONS
Intensification of livestock production systems in many countries will increase the risk of spread of serious zoonotic diseases. Concentration of livestock production, particularly pigs and poultry, in peri-urban areas will increase the interface between animals and humans and hence the opportunity for zoonotic diseases to spread from animals to people. It is therefore likely that there will be increased incidence of serious viral diseases such as RVF and avian influenza, bacterial diseases such as salmonellosis and brucellosis, parasitic diseases such as cysticercosis, hydatidosis and trichinellosis, and zoonotic diseases.
Changes in feeding practices for livestock are likely to bring about new VPH and food safety problems. Examples are BSE, salmonella enteriditis of poultry and drug and pesticide residues.
Changes in the ecological situations in which animals are farmed may lead to new VPH problems. Increased irrigation may bring about increased incidence of mosquito-borne and parasitic vector-borne diseases. The clearing of forested areas for farming may result in the spread of novel disease pathogens from wildlife species to domestic animals and humans.
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BOX 10 Examples of recent major VPH problems. Nipah virus. Between October 1998 and May 1999, 901 228 pigs from 896 farms in Malaysia were destroyed following diagnosis of the previously unknown Nipah virus. There were 257 cases of febrile encephalitis and 100 human deaths. The disease was diagnosed in abattoir workers exposed to body fluids of slaughtered pigs. This outbreak accentuated the need for speedy diagnosis and early assessment of VPH implications. It forced countries importing from Malaysia and receiving tourists to reassess their contingency plans for safeguarding human and animal health. Over and above the direct consequences of the disease, the ease and speed of international travel and contingent risks are becoming major factors in safeguarding human and animal health. RVF. Until 1977, this mosquito-borne viral zoonotic disease was confined to sub-Saharan Africa. It occurred in Egypt in 1977 and again in 1993, causing an estimated 200 000 human cases with some 600 deaths, as well as numerous deaths and abortions in sheep, cattle and other livestock species. Following heavy El Niño rains in 1997-98, a serious outbreak was experienced in East Africa that caused livestock losses and human deaths as well as disrupting the valuable livestock trade to the Near East. During 2000, an outbreak of RVF occurred in Saudi Arabia and Yemen, the first time that the disease has been recorded outside Africa. BSE. This prion disease of cattle was first recognized in the United Kingdom in 1986. Since then, over 180 000 cattle have died or have been slaughtered. The disease is associated with the feeding of contaminated meat/bone meal. Cases have now occurred in other European countries. Discovery of a causal link between BSE and nvCreutzfeld-Jakob disease in humans in 1996 led to major disruptions in the world beef trade. Crimean Congo haemorrhagic fever. Several incidents in abattoirs indicate that traditional procedures of ante and post mortem inspections need to be complemented or revised, taking into account risk factors associated with procurement of animals. In 1996, 17 abattoir workers at an ostrich abattoir in South Africa contracted Crimean Congo hemorrhagic fever after handling a carcass suspected of being in the viraemic phase of the disease.The disease is caused by bites from infected ticks of Hyalomma spp. The abattoir workers who contracted the disease were all working in the defeathering section, where the process of removing hard feathers from dead ostriches resulted in scratches and other injuries on their hands that gave entrance to infected blood from the sick ostrich. Anthrax. This disease is still prevalent in many countries. Serious outbreaks, with deaths among domestic and wild animals, have ocurred in recent years in Africa and Asia, where there have been human fatalities through eating infected meat. Poor livestock farming communities are particularly vulnerable. Avian influenza. Epidemics have occurred in a number of countries in recent years, causing severe losses in poultry flocks. The AI virus strain that caused a major outbreak in Hong Kong in 1997 also caused human disease with deaths. It may have the potential to cause human pandemics. Brucellosis and tuberculosis. These diseases still cause major losses in small and large ruminant animals in many parts of the world. They remain major VPH problems. Salmonella enteritidis, verotoxic E. coli, and listeriosis. These are emerging as major food borne disease problems around the world. |
INSTITUTIONAL ISSUES AND IMPACT OF STRUCTURAL-ADJUSTMENT PROGRAMMES
Evaluations of VPH services in the eastern Mediterranean and Africa have identified a number of challenges that need to be addressed, including:
Addressing these challenges requires an interdisciplinary approach. Developed countries and international organizations have made major changes in their approaches to VPH and food safety in recent years in response to intensifying production systems and the increased requirements for risk-based assessment resulting from increased international, regional and national trade in livestock and livestock products. In New Zealand, Canada, the United Kingdom and the European Union, for example, food-control authorities were established by combining functions previously carried out by traditional agriculture and government health departments into one governmental executive body. The FAO/OIE/WHO forum on VPH in Giulianova (Italy) noted, however, that such an interdisciplinary approach to VPH service delivery has not occurred in many developing countries.
Different requirements exist for VPH and food-safety services at local, national and international levels. Current regulations are in many cases complex, with different standards for quality, health certification and acceptance for human consumption applied by a multitude of disciplines and government agencies. In many developing countries, controls over production, health certification or sale of animal products and food in general are governed by an astonishing number of acts, regulations and by-laws executed by an increasing number of government agencies, each with its own vested interest. This often results in confusion and multiple involvement. Most countries need to consider adopting three basic standards: an international standard for international trade, a national standard for national trade and a standard for local consumption.
As with control of purely livestock diseases (Chapter 2), structural-adjustment programmes have greatly influenced the delivery of VPH and food-safety services. Effective structural adjustment is more easily attainable in developed countries, because they already have an established hygiene culture and high levels of VPH awareness. In such circumstances, the private delivery of public goods is more easily regulated and phytosanitary guarantees in terms of international conventions and commitments can be met. Constraints in developing countries, however, prevent them from following this pathway. Structural adjustment in developing countries should be a gradual process of phasing in essential VPH concepts, with local and national commitment to VPH and food-safety goals being established before attempts are made to comply with international requirements.
THE IMPACT OF POLITICAL AND SOCIAL INSTABILITY ON VPH
Of the 40 poorest countries in the world, 24 are either in the midst of armed conflict or have recently emerged from it. The effect on food safety and VPH issues was seen in the increased incidence of anthrax in cattle in Zimbabwe during the 1970s, when more than 140 people were alleged to have died after consuming infected meat. Recent conflict over land reform in Zimbabwe is impeding normal animal-health practices, resulting in deaths among inhabitants of rural communities in southern Zimbabwe after consuming meat from infected carcasses.
In Burundi and Rwanda, continuous conflict resulted in massive movement of animals and humans across international borders, contributing to an unstable animal-disease situation and total collapse of regulatory services in respect of animal and human health.
In many developing countries, getting the technology right is only part of the solution; making it compatible with cultural, economic, social and physical conditions is also necessary. The practice of transhumance, particularly in North and West Africa, poses unique animal-health and VPH challenges that cannot be solved by traditional approaches. This relates especially to ways of addressing ownership and the relationship between ownership and herd productivity. Establishment of communication and delivery of new technology, especially in attempts to establish the need for veterinary interventions, are challenging and beyond the scope of normal VPH perceptions.
An important issue is the trade-offs between food security and food safety. In situations of food insecurity, farmers and consumers are more likely to consume unsafe products such as meat from carcasses infected with anthrax or parasitic diseases. In some countries, for economic reasons, unregulated meat and milk markets have developed with little or no food-safety capacity.
EFFECTS OF CLIMATE CHANGE ON VPH AND FOOD SAFETY
Evidence suggests that human activities are warming the planet; climate models predict an increase in global mean temperature of between 1ºC and 3.5ºC during the twenty-first century. Global climate change will alter the distribution and risk of vector-borne zoonoses. There is speculation that this will contribute to the increase of West Nile fever in the United States of America. Expected changes in rainfall, wind patterns and seasonal weather variations became evident with the floods in Mozambique in 2000 and 2001. These floods resulted in severe food-security risks and accompanying health incidents such as cholera and malaria. Other examples include an increase in fascioliasis in Bangladesh, China and countries in the Mekong delta.
ISSUES OF TRADE AND RISK ASSESSMENT
As with livestock diseases (see Chapter 2), an increased risk of zoonoses and food-borne infections is associated with globalization and increased trade in livestock and livestock products. The changing international environment has resulted in an apparent dichotomy in VPH involvement: increasing demand for food-safety and health assurances to facilitate international trade and simultaneous increased demand for safe and wholesome food. There is no clearly defined response to the enormous challenge of meeting both demands, especially in developing countries.
Most developed countries and international organizations have responded significantly to the new challenges to VPH service delivery and consumer concerns over food safety. It remains debatable, however, whether these responses will have the same outcome for the 830 million food-insecure people in developing countries. Developed countries have encouraged initiatives towards regional and multilateral trade agreements, reducing government support for the farming sector and liberalizing market access. They have established science-based food-safety regulations in terms of the sanitary and phytosanitary standards under the Uruguay Round global trade accord. The Agreement on Sanitary and Phytosanitary Standards of the WTO (the SPS Agreement) aims to eliminate the use of unjustified, unscientific regulations to restrict trade. Under the new rules, countries have the right to set their own standards of food safety and animal and plant health. This right has been put to the test mostly by developed countries. These untested new standards, however, may be subject to some of the more contentious trade issues in the new millennium and will exert increasing pressure on delivery of VPH services in developed and developing countries. Recent disputes between countries under the SPS Agreement gave rise to accusations of protectionism and creation of non-tariff barriers to trade. There has been confusion resulting from a perception of different sets of standards to differentiate between quality and food safety, quality and hygiene requirements, household food security and international trade, regional and international trade and the needs of household consumers and international demand.
Current live and postmortem meat inspections are usually restricted to the application of hygiene procedures from the time when an animal enters an abattoir until the carcass leaves the premises. In many countries, these procedures may be inappropriate to diseases present in a particular class of livestock. In some situations, less intensive procedures may achieve equivalent results. It is unrealistic to think that the delivery of VPH and food-safety assurances in developing countries can always reach international trade standards. Simpler procedures may be sufficient for food-safety assurances at grassroots level. Application of Hazard Analysis and Critical Control Point (HACCP) procedures and other manufacturing processes are commendable but must be adapted to local demands such as informal slaughter of animals within villages. The primary aim should be to ensure that safe food is offered for sale, even if the animal was slaughtered under a tree. Even under these primitive situations, establishment of a VPH hygiene culture should be the aim, with the application of adopted HACCP and good management practices to ensure that food leaving a place of slaughter poses no health risk. Development of appropriate risk-assessment is a challenge to all developing countries.
