According to a ProMED Post on July 6th, authorities in Denmark confirmed an outbreak of H5N8 strain highly pathogenic avian influenza on July 5th.  The outbreak occurred in Iller, Syddanmark in Southern Denmark.  The affected farm comprised a 38,000 flock producing table-egg that demonstrated clinical signs consistent with avian influenza on July 4th with confirmation of the diagnoses the following day by RT-PCR assay at the Statens Serum Institute National Reference Laboratory. This event casts doubt on the efficacy of the so-called ‘Danish entry’ system as a substitute for shower-in-shower-out biosecurity.  

The flock was culled on July 7th and carcasses were disposed of by rendering.  Appropriate 1.8 mile and 6 mile zones were established around the index farm in accordance with EU Council Directive 2005/94/EC.  The affected farm was located adjacent to the north bank of the Flensburg Firth presuming proximity to free-living waterfowl.

The outbreak confirms that wild birds in Western Europe are still caring the virus that can be transmitted to commercial flocks as a result of deficiencies in biosecurity.  Continual outbreaks of H5N8 avian influenza have long since passed the usual April cutoff for infectivity. This indicates a change in the epidemiology of the virus in free-living birds since by early July, they are breeding and in a post-migration period.