Submitted to: Journal of Parasitology
Publication Type: Review Article
Publication Acceptance Date: June 26, 2000
Publication Date: June 26, 2000
Over the past 20 years epizootics and epidemics involving many viral bacterial and parasitic diseases have emerged that represent global threats to animal and human health. In the past 5 years alone epidemiologists and public health workers have been alerted to many human and animal diseases transported from one country to another. Many of these infectious agents are vector borne and ultimately depend for transmission on climatic conditions that are becoming more favorable for the survival of the vectors as the earth's climate is warming. Although temperatures are now approaching those around the end of the 12th century and some predictions warn that these temperatures will facilitate the spread of malaria and other tropical diseases to Europe and North America, they ignore historical evidence that malaria and other fevers were once endemic in many temperate regions and that epidemics reached as far as the Arctic Circle. These diseases are no longer found in most temperate and arctic climates, but th same mosquito vectors remain in many of them, suggesting that temperature is but one of many factors influencing disease transmission. The resurgence or emergence of many diseases can also be attributed to population growth, urbanization, people movement, dwindling financial and political support, disruptions from war and civil strife, poor public health services, ecological change, deforestation, irrigation, poor vector control, insecticide resistant mosquitoes, drug resistant microbes, and natural disasters. Primarily parasitic diseases, but also a few major diseases caused by other infectious agents, are presented as examples of emerging diseases in the following discussion.