A.V. ANDREEV1, M.V. KRASNOV1, L.P. NIKITINA2  1I.N. Ulyanov Chuvash State University, Cheboksary 2Republican Children’s Clinical Hospital, Cheboksary  Contact details: Andreev A.V. — Assistant Lecturer of the Department of Children’s Diseases Address: 15 Moskovsky prospekt, Cheboksary, Russian Federation, 428000, tel.: +7-903-322-49-16, e-mail: 484916@mail.ru  The purpose — to analyze the Russian and foreign scientific literature on the […]