Death by bird flu is not pretty. A chicken might start sneezing and coughing, struggling to breathe. Or its stubby legs might wobble as the bird struggles to move, eventually falling down or losing consciousness. In 48 hours, it will be dead, because there is no cure for this virus, which is hitting farms across the U.S. Midwest in what has been described as the worst bird flu outbreak in recent memory.

This week, farmers in Iowa, Wisconsin and Minnesota announced they would have to kill a total of more than 5 million chickens, joining other poultry producers who have been forced to kill millions of sick turkeys since the virus began spreading in March. Once birds are infected, euthanasia is the best way for farmers to effectively deal with the sick poultry, especially as they struggle to effectively prevent the virus -- transmitted through bird droppings -- from spreading in other ways, experts say.

“Depopulation is the best control measure,” Dr. Kyoungjin Yoon, an avian influenza expert at Iowa State University, said. The virus’ spread has been attributed to wild birds, like ducks and geese, dropping excrement as they fly on migratory pathways, but “we can do only so much to control wild birds,” he pointed out.

Biosecurity Failure

The current outbreak, which dates to December, has infected more than 7.3 million turkeys and chickens so far. Vaccines, which generally are not used, are not entirely effective in preventing the virus from spreading, while biosecurity -- sanitation protocols that are the first line of defense to prevent the virus from entering farms -- has been mysteriously failing.

“The puzzling thing about this virus is that the biosecurity that we thought was good doesn’t seem to be stopping it,” Jim Roth, director of the Center for Food Security and Public Health at Iowa State, said. “People are scrambling to figure out what more is needed.”

Dr. Sherrill Davison, director of the poultry lab at the University of Pennsylvania’s School of Veterinary Medicine, described the biosecurity as a careful, step-by-step process. When she visits farms, she makes sure her truck is clean, both inside and out. “I shower, make sure all my clothes are washed,” she said. Once she’s at the farm, she dons boots, coveralls and a hat and dips her boot-covered feet into a foot bath before entering any poultry house.

Roth said he was surprised by how many poultry houses have been hit by the virus, given the methodical care taken to prevent pathogens from entering these facilities. “If it’s being spread by dust or flying insects, that’s pretty hard to stop. But we don’t know.”

Although other countries do, the United States does not vaccinate poultry flocks against the virus. Vaccinating birds adds to production costs, and it also doesn’t guarantee against infection and outbreaks, experts point out.

“Vaccination itself cannot prevent infection,” Yoon said. A vaccinated bird might show no signs of being sick, but it can still pass the virus to other birds. “We do need more research to develop better vaccines,” he said. The U.S. Department of Agriculture is working on a vaccine, but there’s no timeline for when it might be ready.

Lesson Learned

The solution of humanely euthanizing birds during such an outbreak is a lesson learned from the last major bird flu outbreak, which hit the U.S. Northeast in 1983 and 1984 and killed roughly 17 million birds, Davison, the UPenn lab director, said. She said the current outbreak, though, was worse.

Still unknown is what effect the outbreak will have on the poultry market. Yet experts suggest its effects will become apparent soon, if they haven't already.

“Economically, producers are going to be hit hard,” Yoon said. Though the U.S. Centers for Disease Control and Prevention has said the virus poses a low risk to humans, consumers nevertheless tend to grow wary and buy fewer poultry products, he said. As a result, farms with healthy flocks still can be hurt by the outbreak.

Producers who have had to euthanize flocks are also directly hurt by the loss of their birds. “There’s an extremely devastating economic effect on the producers themselves,” Davison said. Farmers could lose income from nine months to one year if they lose flocks to the flu.

“At this stage, the economic impact is to the farmers who are losing birds,” Simon Shane, a poultry industry consultant and an adjunct professor of poultry science at North Carolina State University, said. Although the price of eggs and other poultry products could eventually be affected, he suggested that the number of birds that had been euthanized so far was not significant enough to drive up costs, especially when compared to the number of birds usually slaughtered for food. “We’re killing about 5 million turkeys every week,” he said, so “it’s not a very big hole.”