According to a U.S. Department of Agriculture (USDA) report, migratory wild birds are not solely to blame for the rapid spread of avian flu.
Though the wild birds are responsible for introducing the virus into the U.S., USDA Animal and Plant Health Inspection Service (APHIS) found the disease was being transmitted to different farms in many ways, including lapses in biosecurity and environmental factors.
The report also said the virus may have been spread through the sharing of equipment between an infected and non-infected farm, employees moving between farms, a lack of cleaning and disinfection of vehicles moving between farms, rodents or small wild birds and high winds.
As of June 9, there were 222 detections of avian flu in 16 states, depopulating more than 47 million birds.
Click here for more information on the APHIS report.