Influenza, commonly shortened to "flu" is an extremely contagious respiratory illness caused by influenza A or B viruses. Flu appears most frequently in winter and early spring.
A virus affecting garden birds is spreading to new parts of the UK, researchers are warning. This form of avian pox causes lesions, often around the eyes and beak. The virus, affecting great tits, is believed to be a new and more severe strain of a disease that has affected other bird species for several decades.