Duck hunter exposed to type of bird flu

By Maggie Fox, Health and Science Correspondent

WASHINGTON (Reuters) – A U.S. duck hunter and two state
wildlife employees had evidence of an uncommon type of bird flu
virus in their blood, researchers reported on Monday in one of
the first studies to show that hunters might be at risk.

The virus was H11N9, not known to be dangerous to humans
and not related to the feared H5N1 virus circulating in wild
and domestic birds and among some people, the researchers said.

But their study, published in the journal Emerging
Infectious Diseases, shows that people who work with wildlife
should take care.

“To our knowledge, this study is the first to show direct
transmission of influenza A viruses from wild birds to humans,”
Dr. James Gill of the University of Iowa and colleagues wrote
in their report.

The H5N1 avian influenza virus has not yet caused a human
pandemic, but it has killed 132 people out of the 230 infected.
It has infected birds in about 50 countries and is spreading
faster than any other avian influenza ever has.

Many experts believe it may pose the worst threat of an
influenza pandemic in 30 years.

The natural host is ducks, and migrating waterfowl have
been shown to spread the disease. Most ducks do not become sick
from avian influenza, but some strains can kill chickens in a
day.

NO PROTECTIVE GEAR

The researchers studied 39 duck hunters who were hunting in
southeastern Iowa at Lake Odessa Wildlife Management Area, and
68 Iowa Department of Natural Resources employees who either
hunted or help band wild ducks.

Three of the men had antibodies against H11N9, suggesting
they had either been infected in the past or had fought off an
infection.

All three “had substantial lifetime exposures to wild
waterfowl,” the researchers wrote.

None of the other hunters or wildlife workers had evidence
of H11N9 virus in their blood, the researchers said.

In addition, the two wildlife employees had antibodies
against a mallard duck strain of H2N2 influenza, which caused
human epidemics in the 1950s and 1960s.

“Even though the H11-positive study participants had
several years of exposure to wild birds infected with avian
influenza virus through hunting and duck banding, they did not
wear personal protective equipment, such as gloves, masks, or
eye protection,” the researchers wrote.

They did not ask the three men if they had flu-like
symptoms.

“Although the sample size of our study was relatively
small, our results suggest that handling wild waterfowl,
especially ducks, is a risk factor for direct transmission of
avian influenza virus to humans,” they wrote.

The U.S. Fish and Wildlife Service and the U.S. Geological
Survey are testing wild birds for H5N1 flu, which has not been
seen in the Americas yet.

“Many species that breed in Alaska migrate and winter
throughout parts of Russia and Asia,” the USGS says in a
statement on its Internet Web site at http://alaska.usgs.gov/.

“Birds could be exposed to H5N1 in Asia or Russia during
winter or on migration and carry the virus to Alaska in spring
along migratory corridors.”