Kazan medical journalKazan medical journal0368-48142587-9359Eco-Vector5547110.17816/kazmj55471Research ArticleThe current state of the issue of the etiology of influenzaPechnikovaV. N.info@eco-vector.com1302194036284881912202019122020Copyright © 2020, Pechnikova V.N.2020<p>Influenza, or epidemic flu, usually occurs in the form of rapidly spreading epidemics, which speaks for the infectious nature of this disease.</p>Kazan Medical archiveКазанский медицинский архив