Avian influenza
Avian influenza is a contagious infection of birds caused by influenza A viruses. Some strains also infect mammals, including humans.
Influenza A virus: A group of influenza viruses classified by their surface proteins and capable of infecting birds and mammals. Avian influenza is caused by influenza A viruses, whose subtypes shape host range and disease.
Avian influenza surveillance: The systematic detection and monitoring of avian influenza viruses in birds, mammals, and environments. Surveillance identifies circulating strains and outbreaks before or during spread.
Highly pathogenic avian influenza: A classification for avian influenza viruses that cause severe disease in chickens or turkeys under defined criteria. These strains can cause high poultry mortality and trigger large control responses.
Seasonal influenza: Recurring human influenza epidemics caused mainly by influenza A and B viruses adapted to people. It spreads routinely among humans, unlike most avian influenza strains.
Hemagglutinin: An influenza virus surface protein that binds host-cell receptors and helps the virus enter cells. Its subtype, such as H5 or H7, helps name avian influenza viruses.
Poultry vaccination: The use of vaccines to reduce disease or virus transmission in domestic poultry. Vaccination can limit losses and viral spread, though it does not replace monitoring.
Low pathogenic avian influenza: A classification for avian influenza viruses that cause limited disease in chickens or turkeys under defined criteria. Low pathogenic strains can circulate unnoticed and, in some lineages, evolve into highly pathogenic forms.
Swine influenza: Influenza infection in pigs caused by viruses that circulate in swine populations. Swine influenza is another animal-associated influenza, with distinct host ecology and transmission patterns.
Neuraminidase: An influenza virus surface enzyme that helps newly formed virus particles leave infected cells. Its subtype supplies the N in avian influenza designations such as H5N1.
Biosecurity: Practices that prevent infectious agents from entering, spreading within, or leaving a population or facility. Farm biosecurity reduces contact between poultry, wild birds, and contaminated materials.