Abstract

Conservation medicine is an emerging discipline that links human and animal health with ecosystem health and global environmental changes.¹ The biosphere is threatened by three pervasive and synergistic phenomena that are the result of increasing human pressures on the planet: climate change, biologic impoverishment (loss of biodiversity and ecologic processes) and global “toxification” (pollutants such as endocrine disrupting chemicals). The loss of species, the degradation of ecologic processes and the contamination of the web of life are working in concert to diminish human and environmental health on this planet.²

The global loss of biologic diversity affects the wellbeing of both animals and people. Human impact on ecosystems and ecologic processes is well documented. Habitat destruction and species loss have led to ecosystem disruptions that include, among other impacts, the alteration of disease transmission patterns (e.g., emerging diseases), the accumulation of toxic pollutants, and the invasion of alien species and pathogens. The health implications of these disturbing events require novel strategies for disease prevention, health management and conservation.

Complex environmental problems increasingly require multidisciplinary solutions, which can be facilitated through inter-institutional collaboration.³ The Center for Conservation Medicine (CCM) is a consortium created to examine and address ecologic health issues as they relate to conserving the biosphere. By bringing together veterinarians, physicians, ecologists, and other conservation professionals, CCM has begun to examine and address conservation concerns from a health standpoint.

The presence of disease in individuals and populations can be an indicator of environmental health including local and global environmental impacts and ecosystem changes. All over the world, previously contiguous expanses of wild lands are being fragmented by encroachment of agriculture and other human activities. Habitat fragmentation and destruction are having many serious effects on species survival. Using science, wildlife management, veterinary care, training and education, we are working toward mitigating the impacts of fragmentation on species whose survival will necessarily be within small, often isolated, habitat patches. A key area for this work is the Atlantic Forest of Brazil, the rarest rain forest habitat on the planet and only 2% of its original extent remains. Within these forest fragments are some of world’s most endangered wildlife and plant species. This ecosystem creates opportunities for disease transmission among species of wildlife, livestock, and humans. However, the species of wildlife, the diseases, the climate, and the forest structure and composition are all different, as are the economics and sociology of managing these issues. The CCM is developing a buffer zone research effort and examining the health, the risk of disease transmission among fragments, and the viability of the endangered species inhabiting this rainforest.

At the present time, the importance of wildlife diseases is recognized by private and governmental agencies in few countries. The CCM has ongoing collaboration with Mexican institutions regarding efforts to diagnose and control disease in migratory waterfowl populations during their wintering migration. Increasing data on disease agents in a greater number of species and scattered locations raise questions regarding the possibilities of disease introduction and exchange between geographic areas. There is supported evidence of annual reintroduction of disease agents from areas south of the United States by migratory birds such as avian influenza, equine encephalitis and avian cholera.⁴ Surveillance for currently known diseases and isolation of new etiologic agents can be the initial attempt to establish the status of waterfowl diseases in Mexico. The CCM is coordinating the effort to form a wildlife health cooperative in Mexico.

Human population expansion and unsustainable rural development are serious problems for much of the developing world, and climatic and environmental change has exacerbated the situation. The environmental consequences of these two issues are vast—including loss of species and genetic diversity, and the spread of disease. In much of sub-Saharan Africa, these issues are reflected in an overall drop in the quality of life, with an increased proportion of the people living in abject poverty, and the ever-increasing unsustainable use of what should be renewable natural resources. In East Africa these pressures have led to the fragmentation or loss of much of Africa’s pastoral and savanna areas. In the northern reaches of Kenya, Meru National Park has experienced heavy poaching and the loss of most of the major wildlife populations over the years, leading to vegetative imbalances and a general deterioration in ecosystem health. The CCM has begun working with the Kenya Wildlife Service and others to reverse these trends, and to stabilize or even restore this critical ecosystem. This endeavor will require a truly integrated approach, and the collaborative efforts of many partners.

Literature Cited

1.  Pokras MA, Tabor G, Sherman D, Pearl M, Epstein P. Conservation medicine: an emerging field. In: Raven PH, ed. Nature and Human Society. Washington, DC: National Academy Press; 1999:551–556.

2.  Epstein P. Climate and Health. Science. 1999;285:347–348.

3.  Meffe GK. Conservation Medicine. Cons Biol. 1999;13:953–954.

4.  Aguirre AA, McLean RG, Cook RS, Quan TJ. Serologic survey for selected arboviruses and other potential pathogens in wildlife from Mexico. J Wildl Dis. 1992;28:435–442.