Avian influenza is an infectious disease that mostly affects wild birds . Aquatic birds - in particular, anseriforms (ducks, geese, swans and mallards), gulls, cormorants, herons and storks - serve as reservoirs of infection .
Under certain conditions, when contact is easier, the viral infection is transmitted from wild birds to domestic ones (such as turkeys, laying hens and chickens ), in which it can also cause epidemics with high mortality (up to 90-100%) . Contagion among susceptible birds occurs most commonly via the fecal-oral route, through ingestion and / or inhalation of infected material. In farms along the natural migratory routes of wild birds cyclical foci of avian influenza are observed.
Type A influenza viruses, responsible for avian influenza, can infect sporadically some mammals (pigs, horses, etc.), as well as humans, following contact with infected animals (living or dead) or surfaces contaminated with faecal material infected avian, urine, saliva and respiratory secretions. There is no scientific evidence of transmission, instead, through the consumption of poultry meats or eggs properly cooked (> 70 ° C). The safe handling of raw meat and other food ingredients, good cooking and careful kitchen hygiene can still prevent or reduce the risks posed by contaminated foods.
So far, outbreaks of avian influenza in Italian poultry have proven to be relatively safe for humans. In countries where serious cases of human disease have occurred, the transmission of the disease occurred due to prolonged and close contact between humans and infected domestic birds . The risk is considered higher during slaughter, plucking, meat processing and poultry preparation for the kitchen. In Asian countries, for example, the virus often spreads in markets where live poultry is sold or is transmitted from one farm to another through contaminated tools, cages and feed.
