* Partner laboratory
Influenza A viruses belong to the family Orthomyxoviridae and are mostly found in humans, pig, poultry and horses, but also in many others such as birds or dogs.
Equine influenza is caused by the subtypes influenza A equi 1 (H7N7) and A equi 2 (H3N8), although H7N7 has not been very present anymore over the past 30 years. In susceptible Equidae, an infection causes fever and a rough, dry cough. In unvaccinated populations, the virus spreads quickly. Secondary bacterial infections with mucopurulent nasal discharge are frequent and mask the clinical picture, especially in partially immune populations.
Pig may not only become infected with porcine, but also with human and avian influenza viruses and thus contribute to the creation of reassortant influenza viruses. The influenza pandemics in humans in 1918/19 and in 2009 were caused by porcine influenza viruses. In swine, primary infections are usually linked to livestock transport. The infection spreads explosively in the population.