1. Voivodeship Sanitary-Epidemiological Station in Olsztyn, Laboratory of Epidemiological and Clinical Research, Department of Virology and Serology, Zolnierska Str. 16, 10-561 Olsztyn, Poland
2. Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego Str. 1A, 10-719 Olsztyn, Poland