Authorities in Vietnam have culled more than 100,000 chickens and ducks over the past two months.  Both H5N1 and H5N6 have been diagnosed in 14 provinces with the potential to extend to the national poultry flock of approximately 460 million birds.  Avian influenza can be regarded as endemic in the nation and persists in small family operated subsistence and semi-commercial units. These distribute birds through a live marketing system to be sold in wet markets in urban areas.