Outbreaks of END severely affect the poultry industry. In 1971, a major outbreak occurred in commercial poultry flocks in Southern California. In all, 1,341 infected flocks were identified and almost 12 million birds were destroyed. The eradication program cost taxpayers $56 million, severely disrupted the operations of many producers and increased the prices of poultry and poultry products to consumers.
The 2002-03 END outbreak, originally confirmed in backyard poultry in Southern California, spread to commercial poultry operations in California and backyard poultry in Arizona, Nevada and Texas. The Governor of California declared a State of Emergency, the Secretary of the United States Department of Agriculture (USDA) declared an Extraordinary Emergency, and local emergencies were declared in San Diego, Riverside, Los Angeles, and San Bernardino Counties. A USDA and the California Department of Food and Agriculture (CDFA) Task Force was formed that involved over 7,000 individuals rotating in and out over the course of the outbreak. Trade restrictions resulting from the disease had negative impacts on California and U.S. poultry and egg producers. The outbreak, from discovery to eradication, lasted eleven months. The outbreak response led to the depopulation of 3.16 million birds at a cost of $161 million.