|
 Officials with the U.S. Department of Agriculture's Animal and Plant
Health Inspection Service (APHIS) told Reuters the H5N2 virus –
along with two other highly pathogenic strains of bird flu - will
likely be passed among birds at breeding grounds in the northern
United States and Canada through the summer.
When the weather turns cool in the fall, higher numbers of infected
wild birds are expected to move the viruses south again. The strains
are difficult to control, say scientists, in part because wild birds
– especially ducks – can carry the viruses without appearing to be
sick.
The USDA statement marks a shift in tone in the agency's assessment
of the likelihood for a renewed outbreak tied to fall migration.
More than 15 million commercial birds nationwide have died or are
expected to be killed in the current outbreak, and exports of U.S.
poultry and eggs have slowed sharply.
A key concern has been whether the viruses will become endemic in
the nation’s wild bird population, eventually spreading them to the
East Coast and down into the heart of the nation’s chicken broiler
production states in the South and Southeast.
Less than a week ago, USDA’s Chief Veterinary Officer John Clifford
told reporters he wasn’t “forecasting anything for the fall.” If the
virus were to reappear then, Clifford said it would likely be found
along migratory paths that cross over top-producing chicken
productions states such as Georgia, Alabama and Mississippi.
What impact the virus might have on chicken farms in the South is
not known. But the nation’s poultry industry, which is taking an
economic hit from the rapidly escalating outbreak, is extremely
alarmed at the prospect of wider exposure.
One turkey processing plant in Willmar, Minnesota, has reduced its
operations to four days a week because “they don’t have enough
birds,” U.S. Rep Collin Peterson, a Democrat from Minnesota, told
reporters on Tuesday. Other Midwestern poultry producers are
uncertain whether their farms will survive outbreaks of the flu
because of production losses, Peterson said.
“Folks on the East Coast better be paying attention,” said Peterson,
whose state has seen more farms infected with avian flu than any
other.
FEAR OF VIRUS BECOMING ENDEMIC
The outbreak’s reach expanded to 14 states on Tuesday, when APHIS
reported that highly pathogenic H5N2 was identified in two wild
birds in Kentucky.
The avian flu viruses currently killing U.S. poultry first
originated as a single H5N8 virus in Asia, and quickly spread among
wild birds along migratory pathways.
[to top of second column] |
This virus swapped genes with North American influenza viruses to
create the new H5N2 virus, which has been responsible for the
slaughter of millions of chickens and turkeys in the Midwest. It
also spawned a new version of H5N1, a distant cousin of the deadly
Asian bird flu virus.
Based on evidence gathered so far from tracking wild and domestic
birds between December and April, "it is highly probable" that the
viruses will be maintained in some of the North American wild duck
populations through the summer breeding season, APHIS officials said
in an email.
Young birds will be at the highest risk of infection.
“Usually these young birds are the most susceptible ones. They have
no immunity. They are loaded with influenza viruses,” said Dr. Rubin
Donis, an associate director for policy and preparedness in the
Centers for Disease Control and Prevention's influenza division.
If the viruses becomes part of that breeding reservoir, “then we may
be doing control and eradication for years to come,” Donis said.
“The problem is with wildlife, there is no way to control their
movements or their methods.”
As young, infected “hatch-year” birds mingle with other hatch-year
birds and adults during the migration season, “we anticipate higher
numbers of infected birds next fall to move these viruses south
again, into areas in which they are currently being detected and
potentially areas where we have yet to detect them,” APHIS said in
the statement sent to Reuters.
The USDA said a team of state and federal veterinarians, wildlife
biologists and other scientists have developed a plan to track
highly pathogenic avian flu among migratory birds. A draft of the
plan is due to be released to the public on June 1.
(Reporting By Julie Steenhuysen and P.J. Huffstutter in Chicago.
Additional reporting by Tom Polansek in Washington D.C. Editing by
Michele Gershberg and Sue Horton.)
[© 2015 Thomson Reuters. All rights
reserved.] Copyright 2015 Reuters. All rights reserved. This material may not be published,
broadcast, rewritten or redistributed. |
