Low-risk H5N1 bird flu found in Pennsylvania ducks

WASHINGTON (Reuters) – Mallard ducks in Pennsylvania have
tested positive for a low-pathogenic strain of the H5N1 bird
flu virus, the U.S. Agriculture and Interior departments said
on Saturday, adding to cases detected recently in Maryland and
Michigan.

A strain of the H5N1 avian influenza virus was found in
wild ducks sampled August 28 in Crawford County in northwestern
Pennsylvania.

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

The government said it was conducting additional tests to
determine, in part, if the ducks had H5N1 or two separate
strains with one virus contributing H5 and the other N1. A
second round of tests could take five to 10 more days to
confirm whether it was the low-pathogenic H5N1 bird flu.

The virus also has been found during the last month in
Michigan and on Friday in Maryland. 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 U.S. departments of Agriculture and Interior are
working with states to collect between 75,000 and 100,000 wild
bird samples in addition to more than 50,000 environmental
tests throughout the United States.

A low-pathogenic strain, which produces less disease and
mortality in birds than does a high-pathogenic version, poses
no threat to humans. It is common for mild and low pathogenic
strains of bird flu to appear in the United States and other
countries.

The latest H5N1 bird flu strain in Asia, Europe and Africa
is known to have killed at least 141 people and forced hundreds
of millions of birds to be destroyed.

(Additional reporting by Christopher Doering)