H5 bird flu virus in Toyama found to be highly lethal

Monday 20th December, 08:31 AM JST

TOTTORI —

The highly infectious H5 avian flu virus found in a dead swan in Toyama Prefecture is highly lethal and extremely close to the strains that infected birds in Shimane Prefecture and Hokkaido, the National Institute of Animal Health said late Sunday.

Following the announcement, the Environment Ministry upgraded its alert level against avian influenza to the highest rank of 3 from 2 for areas within a radius of 10 kilometers from a park in the Toyama city of Takaoka where the infected bird—a mute swan—was found dead.

In Shimane Prefecture, the highly lethal H5N1 virus was confirmed in chickens that were found infected with flu last month at a poultry farm in the city of Yasugi, after the same virus was detected in October in the waste of a wild duck in Wakkanai, Hokkaido.

The DNA sequence of the virus found in Toyama was 99.7% identical to that of the H5N1 strain seen in Yasugi, and the national institute in Tsukuba, Ibaraki Prefecture is expected to clarify its type on Tuesday, prefectural officials said.

After two dead swans were found Thursday in Takaoka, the Toyama government has culled 10 birds found in the same moat and inspected local poultry farms, and is due to start distributing to all 28 poultry farms in the prefecture Monday lime hydrate as a disinfectant.

Both the highly lethal or virulent and the attenuated viruses of the H5 and H7 bird flu strains are defined as highly infectious under Japan’s Domestic Animal Infectious Disease Control Law.