Avian influenza, a virus that made headlines last week after outbreaks occurred in Asia, Romania and Greece, should not be a large threat to the United States, officials say.
The virus, which is carried by migratory birds like geese and waterfowl, rarely passes to humans, but some human cases have been reported throughout Asia.
Chickens in countries like Indonesia and Thailand contract the virus from other birds, and then the disease can be transmitted to humans through direct physical contact. No human-to-human transmission has been reported yet.
“In Asia their chickens are grown outside, and lots of them are grown on duck ponds, so they are exposed to wild birds more,” MSU professor of poultry science Yvonne Thaxton said. “In the U.S., our birds are grown inside.”
The indoor breeding of chickens should prevent most U.S. birds from contracting the disease. Keeping the animals inside prevents them from coming into contact with migratory birds that carry the disease.
“I don’t think we have to worry about our chickens,” Sanderson Farms veterinarian Marty Ewing said. “We keep our chickens in very secure conditions.”
Also, within the system of chicken farming in the United States, there is very little direct human contact with the animals, Thaxton said. “Very few people actually work with live birds, and those who do take proper precautions to protect themselves. It is very rare that, when somebody’s gotten it, they can’t show a direct association with the birds.”
Most cases of bird flu appear in native birds, chickens more commonly referred to as backyard flocks, Thaxton said. Those chickens bred outdoors often come into contact with feces, blood and other wastes produced by infected birds.
The threat of travelers contracting the disease while in other countries and introducing the virus to the United States remains a worry of most officials.
“We’re more concerned with people going to Asia and bringing the disease back,” Ewing said.
Although chickens are the main sources of disease for humans, Thaxton said it is important to understand that one cannot contract the disease by eating chicken. “You have to be dealing with a wild animal to be at risk,” she said.
Governmental attention, as well as increased cases overseas, stirred up the bird flu scare over the past few weeks.
“We’re watching it, we’re careful, we’re in communications with the world,” President Bush stated in a press conference. “I’m not predicting an outbreak; I’m just suggesting to you that we better be thinking about it.”
The interest the government has in preventing wide-scale deaths brought national attention to the possibilities for a pandemic, Thaxton said. “The potential has existed for years, but once the government got on the bandwagon, it brought national attention,” she said.
However, in spite of the minimal threat to U.S. citizens, the virus can cause major damage, Thaxton said. “The reason it is such a big deal is its potential to become a human virus.”
In order for bird flu to become a human-to-human transmittable virus, the disease would have to combine with another human virus while developing in the chicken. If this happens, humans can transmit the disease to others without knowing it, possibly creating a pandemic situation. The risk is very minimal but still exists, Thaxton said. Precautions can be taken against an epidemic. “We must know where the infected birds are in order to vaccinate, stockpile human and animal vaccines, and have a method of disposing of infected birds.”
“Obviously, the best way to deal with a pandemic is to isolate it and keep it isolated in the region in which it begins,” Bush said.
Vaccination is also a major governmental concern. “It would be helpful if we had a breakthrough in the capacity to develop a vaccine so that not only would first responders be able to be vaccinated but as many Americans as possible and people around the world,” Bush said.
“But, unfortunately, we’re just not that far down the manufacturing process. And there’s a spray that can maybe help arrest the spread of the disease, which is in relatively limited supply,” he added.
Those vulnerable to the virus include the elderly, children and anyone with immune-weakening conditions, Thaxton said. Those who are well nourished, get plenty of sleep and are in generally good health should not fret about contracting the virus, she said.
The most important thing to remember, Thaxton said, is not to worry. “Worrying is stressful. If it comes time to worry, you’ll know.”