U.S. finds low-risk H5N1 bird flu strain in ducks

By Charles Abbott

WASHINGTON (Reuters) – Mallard ducks in Maryland have
tested positive for bird flu, apparently a common, less
pathogenic strain that poses no risk to humans, the U.S.
Agriculture and Interior departments said on Friday.

The H5N1 avian influenza virus was found in fecal samples
from “resident wild” mallards in Queen Anne’s County in
Maryland, on the U.S. central Atlantic coast.

“Testing has ruled out the possibility of this being the
highly pathogenic H5N1 strain that has spread through birds in
Asia, Europe and Africa,” said USDA in a statement. “Test
results thus far indicate this is low pathogenic avian
influenza, which poses no risk to human health.”

Five to 10 more days will be needed for definitive tests to
confirm whether low-pathogenic H5N1 bird flu was found in the
United States for the second time this year. On August 14, the
virus was found in two mute swans in Michigan. Scientists say
low pathogenic avian influenza commonly occurs in wild fowl.

The Maryland mallards did not appear sick so the samples,
collected on August 2 as part of a research project, were not
given high priority when sent to USDA labs for testing.

“The birds are alive and well,” said a USDA spokeswoman.

The low-pathogenic strain of H5N1 has been found six other
times in the United States since 1975. Mild and low pathogenic
strains of bird flu are common in the United States and other
countries.

The H5N1 bird flu strain has killed an estimated 141 people
and forced hundreds of millions of birds to be destroyed,
mostly in Asia. As a precaution, the U.S. government stepped up
testing of wild birds for avian influenza in the continental
United States this year.