Indicators for elevated risk of human exposure to host-seeking adults of the Rocky Mountain wood tick (Dermacentor andersoni) in Colorado.
نویسندگان
چکیده
The human-biting adult stage of the Rocky Mountain wood tick (Dermacentor andersoni) can cause tick paralysis in humans and domestic animals and is the primary tick vector in the intermountain west of the pathogens causing Colorado tick fever, Rocky Mountain spotted fever, and tularemia. We conducted drag sampling studies in Poudre Canyon and Rocky Mountain National Park of Larimer County, CO, to determine microhabitat use patterns by host-seeking D. andersoni adults and find environmental factors signaling elevated risk of tick exposure. Big sagebrush (Artemisia tridentata) was found to serve as a general indicator of areas with elevated risk of exposure to host-seeking D. andersoni adults; this likely results from a shared climate tolerance of big sagebrush and D. andersoni. Grass was the favored substrate for host-seeking ticks. Drag sampling of open grass or grass bordering rock or shrub produced abundances of D. andersoni adults significantly higher than sampling of brush. Sampling sites in Rocky Mountain National Park, relative to Poudre Canyon, were characterized by more intense usage by elk (Cervus elaphus) but decreased brush coverage, smaller brush size, and lower abundances of host-seeking D. andersoni adults. There has been a tremendous increase in the population of elk in Rocky Mountain National Park over the last decades and we speculate that this has resulted in an ecological cascade where overgrazing of vegetation by elk is followed by suppression of rodent populations, decreased tick abundance, and, ultimately, reduced risk of human exposure to D. andersoni and its associated pathogens.
منابع مشابه
MODELING/GIS, RISK ASSESSMENT, ECONOMIC IMPACT Climate-Based Model Predicting Acarological Risk of Encountering the Human-Biting Adult Life Stage of Dermacentor andersoni (Acari: Ixodidae) in a Key Habitat Type in Colorado
We exploited an elevation (climate) gradient ranging from 1,700 to 2,500 m in Poudre Canyon of LarimerCounty, CO, to determine climatic correlates of abundance per 15-s drag sampling time unit (hereafter referred to as abundance) of the human-biting adult life stage of the Rocky Mountain wood tick, Dermacentor andersoni Stiles (Acari: Ixodidae), in a key risk habitat for tick exposure: south/we...
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متن کاملA Canadian bison isolate of Anaplasma marginale (Rickettsiales: Anaplasmataceae) is not transmissible by Dermacentor andersoni (Acari: Ixodidae), whereas ticks from two Canadian D. andersoni populations are competent vectors of a U.S. strain.
Anaplasma marginale Theiler is a tick-borne rickettsial pathogen of cattle with a global distribution in both temperate and tropical regions. The pathogen is endemic in regions within the United States, whereas the Canadian cattle population is considered to be free ofA. marginale. Farmed bison, Bison bison L., in central Saskatchewan have been found to be infected with A. marginale; however, t...
متن کاملSAMPLING, DISTRIBUTION, DISPERSAL Distribution, Seasonality, and Hosts of the Rocky Mountain Wood Tick in the United States
AnaplasmamarginaleTheiler is a tick-bornepathogen that causes anaplasmosis incattle. There are 20 tick species worldwide that are implicated as vectors of this pathogen. In the United States, Dermacentor andersoni Stiles and Dermacentor variabilis (Say) are the principal vectors. The risk of transmission of anaplasmosis to cattle has been largely based on the distribution ofD. andersoni in the ...
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ورودعنوان ژورنال:
- Journal of vector ecology : journal of the Society for Vector Ecology
دوره 33 1 شماره
صفحات -
تاریخ انتشار 2008