Akita, Japan - Following the confirmation that the deadly H5N1 strain of avian influenza was detected in dead and dying swans near Lake Towada in Akita Prefecture, local governments and residents have been working to prevent the infection from spreading.

Three dead ohakucho swans, or whooper swans, and a dying swan were found in an area with a 500-meter radius south of the lake on April 21.

The Akita prefectural government is especially concerned that the deadly bird flu virus outbreak may affect sales of Hinai-jidori chicken, a nationally known delicacy, and other local products.

The Akita prefectural government started inspecting 15 poultry houses belonging to 14 chicken farmers and one egg collector within a 30-kilometer radius of the lake, which includes Odate, Kazuno and Kosakamachi in the prefecture, on Wednesday and Thursday.

Officials are checking whether the poultry houses have taken measures to prevent possible bird flu infection. The moves include setting up guard nets to prevent wild birds from entering the facilities and tanks containing disinfectant to sterilize shoes at farm entrances.

The prefectural government also is providing health consultation services to the public during the Golden Week holidays, while local health care centers are fielding public inquiries related to the discovery of dead birds.

In Aomori Prefecture, where many chicken farmers operate, the prefectural government on Monday started inspecting 39 poultry farmers located within a 30-kilometer radius of the lake.

However, following Tuesday's confirmation that the virus was the deadly H5N1 strain, inspections were expanded to include all 163 chicken farms in the prefecture.

Hotels near the lake are worried about the spread of incorrect information that may harm their business.

An official of the Kosakamachi municipal government's industries division said, "We'll make a flyer to tell people that they don't have to be worried about getting infected with the virus, and distribute it in the town."

According to the Akita prefectural government and others, most of the about 300 swans that spent the winter at the lake have already departed the area, flying back on their northbound migratory route in mid-April.

The prefectural government believes the infected swans passed the winter in an area south of the lake, stopping there while en route to Siberia.

Prof. Koichi Otsuki, who heads Kyoto Sangyo University's Avian Influenza Research Center, said, "It's possible that the birds were infected with the virus through droppings and saliva attached to feed in areas to the south of Lake Towada."

Meanwhile, inspectors from the Environment Ministry's natural conservation office for Lake Towada on Wednesday examined whether the H5N1 virus has spread to wild birds in the area. The inspection has been conducted daily since the infected birds were discovered.

According to the World Health Organization, as of April 17, 381 people in 14 countries have been infected with H5N1 since 2003. Of them, 240 have died.

However, experts believe the Akita Prefecture outbreak poses little immediate threat to humans.