Oct. 10 (Bloomberg) -- German authorities killed 1,400 domestic fowl after identifying the country's first case of avian influenza this year on a commercial farm in the town of Markersdorf, near the Polish border.

A duck tested positive for the H5N1 strain of bird flu, Elke Reinking, a spokeswoman for Germany's Friedrich Loeffler Institute, said in a telephone interview today. Tests confirmed that the animal was infected with the highly pathogenic form of the disease that spreads rapidly among birds, she said.

Authorities began killing poultry at 4 a.m. and have set up a three-kilometer (1.9 mile) quarantine, said Ralph Schreiber, a Health Ministry spokesman in the German state of Saxony. The sick duck was found in an area with several poultry farms, including one with 70,000 animals, Schreiber said.

``The flu can appear again at any time, but it was a bit of a surprise to see it in a commercially raised animal,'' Reinking said. The Friedrich Loeffler Institute is a center for animal health.

Avian flu was last found in Germany in December 2007 in chickens at a small hobby farm, she said. There have been no reports of the disease in neighboring countries since March, when a wild duck tested positive in Switzerland.

How the duck caught the virus remains a mystery, Reinking said. Authorities are testing all fowl in the quarantine area to see whether the disease has spread.

Pandemic

Health authorities have been monitoring the H5N1 strain of avian influenza for more than a decade for any sign that it is becoming as contagious as seasonal flu. While millions of birds have been infected, fewer than 400 people are reported to have contracted the illness, including 36 this year.

The world is closer to another influenza pandemic than at any time since 1968, when the last of the previous century's three pandemics occurred, according to the Geneva-based World Health Organization.

The H5N1 virus has spread to more than 60 countries and caused at least 6,500 poultry outbreaks since 2003. The H5N1 flu strain is known to have infected 387 people in 15 nations in the past five years, 245 of whom have died, according to the WHO.

To contact the reporter on this story: Naomi Kresge in Berlin nkresge@bloomberg.net

Last Updated: October 10, 2008 09:56 EDT