Isolation and characterization of an H10N7 avian influenza virus from poultry carcasses smuggled from China into Italy

Abstract

Intensified official veterinary controls on warehouses supplying Chinese retailers resulted in the seizure of smuggled poultry products. Frozen and vacuum-packed frozen raw duck and chicken carcasses, and anatomic parts (legs) of these species, were collected and processed for laboratory investigations aiming at the detection of avian influenza virus. Real-time reverse transcription-polymerase chain reaction (RRT-PCR) targeting the M gene, performed on the lung and trachea from duck and chicken carcasses, yielded positive results. Virus isolation attempts in specific pathogen free embryonated eggs yielded an H10N7 virus from the duck carcass. The isolate had an intravenous pathogenicity index of 0.0, and phylogenetic analysis revealed a nucleotide homology of 97 and 96% with virus A/duck/Zhejiang/52/2000 (H5N1) for the PB2 and NS genes, respectively. The results of this study indicate that low-pathogenicity avian influenza viruses may be introduced into a country through trade of carcasses regardless of the non-systemic nature of this disease. The export ban applied to countries affected by the H5N1 epidemic may result in increased smuggling of poultry products, which remains one of the means by which influenza viruses can cross-national boundaries. Increased surveillance at borders and at a national level is recommended.