Nevertheless, the implementation of surveillance programs in wild birds aiming the risk assessment of LPAI or HPAI introduction into domestic poultry, is of utmost importance, since both LPAI viruses of H5 and H7 subtypes circulating in wild waterfowl in the vicinity of poultry farms represent a serious threat for the industry (Henriques et al., 2011) as they can easily revert to high virulence. In many countries an “Avian Influenza Surveillance Plan” is in action envisaging the safeguard
of public and animal health through the early detection of circulating viruses.