<unk> s, which afflict humans and other animals, are caused by infectious agents transmitted by<unk>  bites. They are caused by infection with a variety of pathogens, including rickettsia and other types of bacteria, viruses, and protozoa. The economic impact of<unk> s is considered to be substantial in humans, and<unk> s are estimated to affect ~80 % of cattle worldwide. 18<unk> -borne pathogens have been identified in the United States according to the Centers for<unk>  Control and at least 27 are known globally. New<unk> s have been discovered in the 21st century, due in part to the use of molecular assays and next-generation sequencing. The occurrence of<unk> s and<unk> -borne illnesses in humans is increasing.<unk>  populations are spreading into new areas, due in part to the warming temperatures of climate change.<unk>  populations are also affected by changes in the populations of their hosts (e.g. deer, cattle, mice, lizards) and those hosts' predators (e.g. foxes). Diversity and availability of hosts and predators can be affected by deforestation and habitat fragmentation. Because individual<unk> s can harbor more than one<unk> -causing agent, patients can be infected with more than one pathogen at the same time, compounding the difficulty in diagnosis and treatment. As the incidence of<unk> -borne illnesses increases and the geographic areas in which they are found expand, health workers increasingly must be able to distinguish the diverse, and often overlapping, clinical presentations of these<unk> s.
Tick-borne disease
Virgin soil epidemic
Feline zoonosis
Hittite plague
Canine vector-borne disease
Cryptic rabies
Metal fume fever
Polymer fume fever