1. Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland
2. Swiss Tropical and Public Health Institute, Basel, Switzerland
3. University of Basel, Basel, Switzerland
4. Department of Oncology, University Children’s Hospital Zurich, Zurich, Switzerland
5. Department of Oncology/Hematology, Children’s Hospital, Cantonal Hospital Lucerne, Lucerne, Switzerland