Bird flu has killed more than 7 million birds in past month; officials unsure how to contain disease

UPDATED April 29, 2015: New bird flu cases have been reported in Kentucky, Iowa and Minnesota, reports Agri-Pulse. Two wild birds in McCracken County, Kentucky were found to have highly pathogenic avian influenza, five outbreaks were reported at commercial poultry farms in Iowa and a new outbreak of the H5N2 strain was also confirmed in a flock of 27,000 turkeys in Stearns County, Minnesota, the biggest turkey producing state.

"Four of Iowa's latest cases were reported in newly affected counties—two egg-laying operations in O'Brien County, one laying facility and a turkey farm in Sioux—with a fifth case found in Osceola (the county's second outbreak) on a pullet farm raising layer chickens," Agri-Pulse writes. "All told, the operations were raising about 5.8 million birds, all of which are being euthanized to slow the spread of the virus. Combined with previous outbreaks, Iowa will be depopulating almost 10 million chickens and turkeys."

Officials are at a loss about how to contain the bird flu epidemic, which has led to the deaths of 7.1 million birds in the past month—mostly in Minnesota and Iowa—and fear the disease will continue spreading throughout the Midwest and reach the heart of the chicken industry in the South, Kesley Gee and Jacob Bunge report The Wall Street Journal. "Though the casualties so far account for a fraction of the poultry industry’s annual production of about nine billion chickens and turkeys and the egg industry’s 303 million birds, industry and government officials are uncertain how the virus is spreading."

"The outbreak, the poultry industry’s worst since the 1980s, has expanded to more than a dozen states," Gee and Bunge write. "It has prompted many countries to impose bans on imports of U.S. poultry, leading to declines in overseas shipments of turkey and chicken legs, chicken feet and other products." (CNBC graphic)

"The highly infectious H5N2 strain of avian influenza is a combination of a deadly strain that originated in Asia and later combined with North American versions, according to scientists," Gee and Bunge write. "Stricken turkeys and chickens may stop eating or become lethargic, begin to cough and sneeze, and can die off quickly, according to animal health officials."

While researchers believe the virus is spread through "the droppings of wild ducks and geese as they migrate to the upper Midwest to breed during the warmer months of the year," it remains unclear "how the virus enters already tightly managed poultry houses, which typically are enclosed to prevent exposure to pathogens and predators," Gee and Bunge write. "One theory is that poultry workers unknowingly are tracking the droppings into the facilities despite stringent biosecurity practices."

"Farmers and meat companies say that workers typically change boots before entering poultry farms, outsiders usually aren’t admitted and equipment regularly is disinfected," Gee and Bunge write. "Another possibility is that wind gusts may carry virus particles on feathers or bird excrement to poultry facilities." (Read more)