Assessment of the Likelihood of Introducing Bluetongue Disease Through the Importation of Cattle. R. S. Morley and S. A. Renwick, Animal Health Risk Assessment Unit, Agriculture and Agri-food Canada, 3851 Fallowfield Road, Nepean, Ontario, K2H8P9
Bluetongue is a non-contagious viral infection of ruminant animals that occurs in many countries in temperate and subtropical areas of the world. It is a vector-borne disease transmitted by the insects belonging to the Genus Culicoides. The importation of cattle from an area where the vectors and the disease exist into a disease-free area during the non-vector season was assessed as to the likelihood of disease transmission in domestic cattle. A scenario tree emanating from the initiating failure event of importing thousands of potentially infected cattle was depicted. Parameters of this scenario tree included the level of infection in the diseased areas, the calendar period of importations, the period of vector activity, the duration of viremia in infected cattle, and the vectorial capacity and distribution of native Culicoides insects. A simulation using Latin Hypercube sampling of the scenarios possessing the outcome of interest revealed a very low likelihood of disease transmission.