Very serious consequences
It is a scientific certainty that aquatic birds are carriers of the virus.bird flu, but it has never been proven that these are the ones who transported the virus into the farms, with the known serious economic consequences on the poultry sector, which is so important in many areas of Northern Italy. Live calls of anseriformes and chadriforms are also considered a possible vehicle for transporting the virus in farms, but this too is not experimentally proven.
New light on the issue
There is a scientific article that shines a spotlight on the topic, the study of the interface between wild bird populations and poultry and their potential role in the spread of avian influenza. In practice, it is research conducted by Luca Martelli, Diletta Fornasiero, Francesco Scarton, Arianna Spada, Francesca Scolamacchia, Grazia Manca and Paolo Mulatti, and was published in "Microorganisms".
The ways in which the virus enters
This study demonstrates that the possible animal vectors of the virus on farms are to be found in a wider range of species, other than aquatic birds, which live and frequent environments close to these structures, much more than aquatic birds. It seems clear that the ways in which the virus enters farms are diverse and cannot be traced back to aquatic birds alone. In these terms, the role of man/farmer and the correct application of biosecurity measures is the main and most significant tool for preventing the introduction of influenza viruses into farms. In this scenario, the risk attributed over the years to live calls of anseriformes and chaadriiformes as potential causes of the virus entering poultry farms appears to be greatly overestimated (source: FIDC).