During the past week, the Czech Republic confirmed the presence of a highly pathogenic strain of  H5N8 avian influenza in a backyard flock in Vysocina.  This follows recent diagnoses in Poland, Slovakia, Hungary, Romania and possibly Bulgaria.

The strain involved is 99 percent homologous with H5N8 strain clade 2.3.4.4b prevalent in Northern Africa during 2018 and 2019.

Strain H5N8 HPAI first appeared in Europe in 2016 and within a few months, infections occurred in 30 out of 43 nations on the continent. Migratory waterfowl were apparently responsible for introduction and spread of the causal virus. The role of migratory birds in dissemination of HPAI is confirmed by seasonality and isolations from both dead and live- sampled geese and ducks.  Federal officials in Germany confirmed H5N8 in a wild goose in Brandenburg close to the border with Poland during the past week.  In early January 2020, an H5 strain was isolated from hens in Northern Ireland although at this time, the neuraminidase component has not been revealed but is presumed to be N8.

Based on experience in 2016/2017 it appears that 2020 will be a replay of previous seasons.  Clearly free-range egg-production flocks are at high risk especially if located on farms in the vicinity of expanses of water that attract migratory waterfowl.