IMPACTS OF WILDLIFE DISEASES IN URBAN ENVIRONMENTS

Approximately 60% of diseases causing pathogenic illness in humans originate in animals. Emergence and re-emergence of zoonotic and vector-borne diseases pose considerable public health, environmental, and economic impacts in the U.S. There are over 250 urban areas in the U.S. with populations >100,000. These densely populated centers, with concomitant development of natural areas, greenbelts, and walking trails, are viewed to exacerbate the potential for human-wildlife, pet-wildlife, and pet-human interactions leading to greater risks of zoonotic disease transmission. Wildlife rabies, West Nile virus (WNV), and bovine tuberculosis (bTB) offer illustrations of potential impacts from zoonoses in urban areas. Prevention of wildlife variants of the rabies virus are estimated to cost > $250 million annually; probable transmission in urban environments can involve direct human exposure to rabid coyotes (Canis latrans), raccoons (Procyon lotor), skunks (Mephitis mephitis, Spilogale putoris), and red foxes (Vulpes vulpes) or indirect exposure to the virus via pet-wildlife contacts with these animals. West Nile virus is a mosquito-borne illness that has killed >785 people in the U.S.; hospitalization costs associated with the outbreak of this disease in Colorado's densely populated Front Range averaged $33,980/admitted patient. The re-emergence of bovine tuberculosis (bTB) in cattle (Bovidae spp.) of Michigan's northern Lower Peninsula has resulted in a loss of the State's "TB-accredited free" status costing the state an estimated $22-74 million in five years. Monitoring, preventing, and treating zoonotic diseases pose new challenges for public health, veterinary, and wildlife professionals, with densely populated urban environments likely to exacerbate transmission and impacts.