Bird flu spreads in South Korea

Ducks on four more South Korean farms have been found to be positive for the H7N7 sub-type of low pathogenic avian influenza (LPAI).

The veterinary authority has sent Follow Up Report No. 1 dated June 4 to the World Organisation for Animal Health (OIE).

The report describes the discovery of four new farms affected by LPAI between May 18-25. Ducks on all farms were found to be positive for the H7N7 strain of the avian influenza A virus. They were in the two southern provinces of Chulla namdo (where the previous virus-positive birds were found) and in neighbouring Chulla bukdo.

In total, 32,882 were affected and all have been destroyed.

According tot he report, after the previous LPAI outbreaks in Cholla-namdo on May 13, 2010, the local veterinary authorities have been tracing the epidemiologically linked farms and conducting tests for avian influenza.

During the testing for avian influenza, two duck farms in Cholla-namdo and two duck farms in Cholla-bukdo were found to be positive by haemagglutination tests on May 26 and June 2, respectively.

The National Veterinary Research and Quarantine Service (NVRQS) found avian influenza antigen (H7) by PCR on May 26 and June 2. The NVRQS then confirmed it as low pathogenic avian influenza virus (H7N7) by gene sequencing on May 27 and June 3.

The poultry in the farms were culled as a precautionary measure and disinfection and other control measures were implemented. Currently, clinical surveillance and laboratory testing are underway for these epidemiologically linked farms.