1. Department of Environmental Medicine, Poznan University of Medical Sciences, 60-806 Poznań, Poland
2. Department of Children’s Infectious Diseases, Medical University of Warsaw, 02-091 Warsaw, Poland
3. Department of Pediatrics, Centre for Postgraduate Medical Education, 01-813 Warsaw, Poland
4. Department of Pediatrics with Clinical Assessment Unit, Medical University of Warsaw, 02-091 Warsaw, Poland
5. Department of Social Medicine and Public Health, Medical University of Warsaw, 02-007 Warsaw, Poland
6. Department of Infectious Diseases and Hepatology, Faculty of Medicine, Collegium Medicum, Nicolaus Copernicus University, 85-067 Bydgoszcz, Poland
7. Department of Family Medicine, Wroclaw Medical University, 51-141 Wroclaw, Poland
8. Department of Infectious Diseases and Hepatology, Medical University of Silesia, 41-902 Bytom, Poland
9. Department of Pediatric Infectious Diseases, Wrocław Medical University, 50-367 Wroclaw, Poland
10. Department of Preventive Medicine, Poznan University of Medical Sciences, 61-701 Poznań, Poland
11. Department of Infectious Diseases and Hepatology, Medical University of Białystok, 15-089 Bialystok, Poland