Risk assessment of Brucella abortus introduction into California and cost-effectiveness evaluation of the current brucellosis vaccination program

Brucellosis is a serious infectious disease of cattle, caused by Brucella abortus, which can cause devastating economic losses to cattle industry. California has been classified a free of bovine brucellosis since 1997 and, according to a report from the USDA-APHIS 2017, all the United States are now free of brucellosis in cattle. However, brucellosis is still endemic in free ranging elk and bison populations in the Greater Yellowstone Area (GYA), which includes parts of Montana, Idaho, and Wyoming.

Spatio-temporal dynamics of condemnation cases in cattle slaughter plants in California and other US states from 2004-2015

The meat and cattle industry is the largest segment of U.S. agriculture. In 2015 the US commercial slaughter 28.74 million head with the commercial carcass weight of 23.69 billion pounds (National Cattlemen’s Beef Association). Based on the data obtained from USDA in 2015, 141,450 carcasses were condemned in the US which is approximately 0.5% of the total cattle carcasses produced in the US.