Avian influenza in Poland.

Poland has experienced four episodes of avian influenza (AI) outbreaks over the past two decades. The first epidemic was caused by a low pathogenicity (LPAIV) H7N7 subtype and occurred in fattening and breeder turkeys in 1995. Two waves of H5N1 high pathogenicity avian influenza (HPAI) took place in 2006 and 2007. In spring 2006, 64 cases of the H5N1 virus were detected, mostly in mute swans. In December 2007, ten outbreaks of H5N1 HPAI were detected in commercial poultry (n = 9) and wild birds kept in captivity (n = 1). The outbreaks in 2006 and 2007 were caused by genetically similar but clearly distinguishable viruses of the 2.2 clade. In 2013, an H9N2 avian influenza virus was detected in 4 fattening turkey holdings. The virus was low pathogenic and a phylogenetic study has shown a close relatedness to the Eurasian lineage of AIV of the wild bird origin. Neither preventive nor prophylactic vaccinations have ever been used in poultry or other birds. Emergency vaccinations using autogenous vaccine were introduced only to control the H7N7 LPAI outbreaks in 1995. The baseline surveillance for AI in live migratory birds and poultry provides a valuable insight into the ecology of AIV at the wild and domestic bird interface. Passive surveillance is in place of early detection of HPAIV infection in dead or moribund birds.