H7N7 Highly Pathogenic Avian Influenza in Poultry Farms in Italy in 2016

After the H7N7 highly pathogenic (HP) avian influenza (AI) outbreak in 2013, and a single case of H5N8 HPAI in 2014, in April 2016, a H7N7 HPAI virus was detected in northeastern Italy. The case occurred in an organic free-range laying hen farm located in proximity with one of the highest densely populated poultry areas (DPPAs) in Italy. Control measures provided by the Council of the European Union in directive 2005/94/CE were promptly applied, and enhanced surveillance activities were implemented in the DPPAs. On May 16, 2016, a second case was confirmed in a fattening turkey farm within the protection zone of the previous outbreak. Following an epidemiologic inquiry, another turkey farm was considered at risk of transmission and was subjected to preemptive culling. Epidemiologic data and phylogenetic analyses indicated that the virus was likely introduced from wild birds as a low pathogenicity AI strain, through direct contact. The rapid containment of the outbreak proves the level of preparedness of the veterinary public health sector in Italy. Nevertheless, the recurrent introductions from wild birds indicate the need of improving both the biosecurity levels in the DPPA and the surveillance activities in wild birds to quickly detect the presence of AI in the territory.