21 February 2004
An outbreak of avian influenza in several eastern U.S. states in the last few weeks is threatening the region's huge poultry industry, and raising fears of a public health crisis similar to the one now sweeping across Asia. Mary Saner reports on how farmers and health officials are moving to contain the outbreak.
At Alvin Callahan's farm on the Delmarva Peninsula, three chicken houses, each the length of a football field, dominate the landscape. They hold 80,000 chickens being raised for sale to a nearby poultry processor. Mr. Callahan is very nervous these days. His farm is in Maryland, just across the border from a Delaware farm where thousands of chickens have been destroyed to try to control an outbreak of avian flu. The virus spreads easily through bird waste that is tracked on shoes and vehicles moving from farm to farm.
"You've got to be very cautious who comes and who goes and where they go," he explains.
Mr. Callahan stresses that local agriculture officials are doing all they can to stop the spread by urging farmers to stay home. "They don't want anybody to go to any auctions and they've more or less cancelled all the meeting for any farmers to go to. And the waste people, they've taken a lot of those off the farms, picking up trash."
There are different strains of avian flu. The one discovered in this area is a mild one, unlike the bird flu now spreading in Asia, where it has killed at least 22 people.
"This one - there is no history of it actually jumping species and affecting humans - the H7N2. And we feel fortunate that at the first site we have determined that it has low pathogenicity," says Anne Fitzgerald, an official with the Delaware Department of Agriculture. She notes her office has not yet determined how avian flu got onto the two farms here, but suspects it may have been through live bird markets - noisy, crowded bazaars where farmers from many areas come to sell their chickens.
"The first infected farm site is run by a gentleman who does raise birds for sale in the live bird markets in both New York and New Jersey and this particular strain of the virus, H7N2, has been a problem up there and they've had difficulty eradicating this virus. And it does reappear periodically, explains Anne Fitzgerald.
Another possible infection pathway is wild birds. They can carry the disease without symptoms. The Delmarva Peninsula is a major migratory flyway and wintering ground. Alvin Callahan says a lot of his neighbors believe those flocks are responsible for the outbreak.
"They seem to think it might have come from geese, he says. "They can fly over and drop a litter and you walk in it and you won't even know it. And you can carry it into your chicken house."
Since the virus was first detected here earlier this month, 85,000 chickens have been destroyed and composted. Scientists believe heat from the decay kills the virus. Farms within a 10-kilometer radius have been quarantined, and officials continue to test birds throughout the area.
According to Anne Fitzgerald, the longer avian flu virus is out there, the more chance there is for it to mutate into a more deadly strain. "One of the fears is if you have a low pathogenic virus - and it's left untended, it could become highly pathogenic," she says. "What we're trying to do is nip it in the bud."
The U.S. poultry industry is now urging the government to create a strong national system to monitor and track chickens sold at live markets. Meanwhile, more Asian countries are banning imports of Delmarva poultry. But Ms. Fitzgerald hasn't stopped eating the local chicken. "I've been eating it every night almost since this problem began," she says. "I have no problem with eating it, because this does not affect the safety."
Despite the massive effort to contain the spread on the Delmarva Peninsula, new outbreaks of avian flu have been reported recently in neighboring New Jersey and Pennsylvania. Similar control measures are being taken there.