Emerging Zoonoses

摘要

Zoonotic pathogens cause infections in animals and are also transmissible to humans; knowledge of the extrahuman reservoirs of these pathogens is thus essential for understanding the epidemiology and potential control of human disease. Zoonotic diseases are typically endemic and occur in natural foci. However, ecologic change and meteorologic or climatic events can promote epidemic expansion of host and geographic range. For practical reasons, surveillance of zoonotic agents too often relies on the identification of human cases. Surveillance in natural hosts may be difficult because of the ecologic complexity of zoonoses; multidisciplinary teams of ecologists, mammalogists, ornithologists, and entomologists, as well as physicians and epidemiologists, may be required for successful investigations. A recent trend in studying zoonoses that have strong environmental correlates includes geographers and mathematical modelers, who integrate satellite remote sensing and geographic information systems to predict outbreaks. Understanding extrahuman life cycles and predicting zoonotic disease outbreaks may permit control activities targeted at several points in the cycle of pathogen maintenance before human infection begins. These control efforts are important because most zoonoses are not amenable to eradication, except perhaps those in areas where animal reservoirs are targeted for vaccination, e.g., fox rabies in Europe.