![Swine Influenza Viruses detected in European pigs in 2014](https://www.pig333.com/3tres3_common/art/pig333/8748/swine-influenza-viruses-detected-in-european-pigs-in-2014_68285.jpg?w=650&h=366&ho=1&ts=1653979446)
Swine influenza viruses: mechanisms of evolution and current diversity in European pigs
Four virus lineages, having clearly distinguishable HA, are currently co-circulating in European pigs and can be considered as enzootic viruses, even if their relative prevalence and level of incidence vary from one country to another.