2006-2007, providing an early warning that reduced the impact and spread of the disease. Such forecasts, they conclude, may potentially predict risk for the spread of diseases on a global scale and offer health and agricultural authorities the possibility of targeting disease surveillance and control efforts, and thereby improve their cost-effectiveness.
Two consecutive contributions, from workshop speaker Jonathan Patz, of the University of Wisconsin, Madison, and co-authors, discuss the possible effects of global climate change on vector-borne disease emergence. The first paper, by Patz and S. H. Olson, comprises an overview of the effects of climate change on disease risk at both global and local levels. It is followed by an update, by Patz and C. K. Uejio, which presents detailed evidence for the effects of climate change on Lyme disease and WNV, the two most prevalent vector-borne diseases in North America.
Vector-borne pathogens are particularly sensitive to climatic conditions due to their influence on vector survival and reproduction, biting and feeding patterns, pathogen incubation and replication, and the efficiency of pathogen transmission among multiple hosts. The authors discuss evidence that an overall rise in global temperatures could enlarge the geographic range of malaria in Africa and increase the frequency of dengue outbreaks worldwide, but they place greater emphasis on opportunities for disease emergence in local environments driven by land use practices such as deforestation, cultivation, and dam construction. Given these influences, risk assessments for vector-borne diseases should incorporate appropriately scaled analyses of the effects of land use on microclimate and weather, habitat, and biodiversity, the authors conclude. The need for such considerations is clearly illustrated in their discussion of WNV distribution and transmission dynamics, which appear to be influenced by a broad and complex range of environmental factors.
Duane J. Gubler, Sc.D.1
University of Hawai‘i, Honolulu, Hawai‘i
At the beginning of the 20th century, epidemic vector-borne diseases were among the most important global public health problems (Gubler, 1998, 2002a).