1. Department of Pediatric Oncology, Hematology and Transplantology University of Medical Sciences Poznan Poland
2. Department of Pediatric Hematology and Oncology Collegium Medicum Nicolaus Copernicus University Torun Bydgoszcz Poland
3. Department of Microbiology Collegium Medicum Nicolaus Copernicus University Torun Bydgoszcz Poland
4. Department of Pediatric Hematology and Oncology Medical University Warszawa Poland
5. Division of Pediatric Hematology and Oncology Children Hospital Olsztyn Poland
6. Department of Oncology Children’s Memorial Health Institute Warszawa Poland
7. Department of Microbiology Children’s Memorial Health Institute Warszawa Poland
8. Department of Pediatrics Hemato‐Oncology and Gastroenterology Pomeranian Medical University Szczecin Poland
9. Department of Pediatric Stem Cell Transplantation, Hematology and Oncology Medical University Wroclaw Poland
10. Department of Pediatrics, Hematology and Oncology Medical University Gdansk Poland
11. Department of Pediatric Oncology and Hematology Collegium Medicum University Children’s Hospital Jagiellonian University Krakow Poland
12. Department of Microbiology Collegium Medicum University Children’s Hospital Jagiellonian University Krakow Poland
13. Department of Pediatric Oncology, Hematology and Diabetology Medical University Lodz Poland
14. Division of Pediatric Hematology and Oncology Children Hospital Kielce Poland
15. Division of Pediatric Oncology, Hematology and Chemotherapy Department of Pediatric Silesian Medical University Katowice Poland
16. Department of Pediatric Oncology and Hematology Medical University Bialystok Poland
17. Department of Pediatric Oncohematology Children Hospital Rzeszow Poland
18. Division of Pediatric Hematology and Oncology Chorzow Pediatric and Oncology Center Chorzow Poland
19. Department of Pediatric Hematology and Oncology Silesian Medical University Zabrze Poland
20. Department of Pediatric Hematology, Oncology and Stem Cell Transplantation Medical University Lublin Poland