title: Bovine anaplasmosis transmission studies conducted under controlled natural exposure in a Dermacentor andersoni = (venustus) indigenous area of eastern Oregon.
abstract: In Anaplasma marginale transmission studies conducted on the high semi-arid range of eastern Oregon during the 1974 and 1975 vector season, A marginale-susceptible calves (principals) were maintained on 2 raised tick-proof platforms. Anaplasmosis-susceptible control calves of approximately the same age and latent-infected cows grazed the area surrounding the platforms. One latent-infected steer spent the entire 1975 vector season on a platform with the principals. The 28 principals did not develop anaplasmosis, whereas 15 of 30 (50%) controls became infected. The disease was not transmitted from the latent-infected cattle to the principals exposed only to flying hematophagous insects, whereas 50% of the controls exposed to the Rocky Mountain wood tick Dermacentor andersoni) = (venustus) developed the disease. Dermacentor andersoni appears to be the principal vector on this range.
mesh_terms: D000712:Anaplasmosis / Q000276:immunology / Q000635:transmission*; D000818:Animals; D001179:Arthropod Vectors; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000635:transmission*; D002519:Ceratopogonidae; D003870:Dermacentor; D004175:Diptera; D005260:Female; D008297:Male; D009922:Oregon; D013987:Ticks