Worst outbreak of avian influenza on record

In Asia, poultry farmers are on high alert as avian influenza forces a record number cullings.

So far, South Korea has culled 5.5 million birds and Japan has culled 3 million. Just this week, a farm in Japan had to cull 30,000 birds.

The two nations say that this is the worst outbreak on record.

In Europe, another strain is spreading through its flocks. Poultry farmers blame wild birds for spreading the virus.