Hsu Tien-lai, director-general of the Bureau of Animal and Plant Health Inspection and Quarantine under the Cabinet-level Council of Agriculture (COA), said the no H1N1 cases were found in the second and third round of H1N1 tests conducted by the bureau on a farm in Kuanshan township that was infected or on seven others within a three-kilometer radius.

The H1N1 virus was discovered among hundreds of hogs on the Kuanshan township farm Nov. 5, in what was said to be a possible jump of the new flu strain from humans to pigs. However, Hsu said that it is still not clear how the pigs on the farm contracted the virus.

The farm is an enclosed facility and is wired to keep out birds, he noted, adding that the possibility of infection from other farm animals or people in passing vehicles was quite low.

According to Hsu, the results Monday showed that the samples from all the farms in question tested negative for the virus strain, which indicates that the outbreak has been contained after close monitoring.