1. Hiroshima City Medical Association-administered Hiroshima City Aki Hospital
2. Department of Infection Control and Nursing, Graduate School of Health Care and Nursing, Juntendo University
3. Nanki Shirahama Onsen Rehabilitation Center, Shirahama Hamayu Hospital
4. Department of Infectious Diseases, The University of Tokyo Hospital
5. Department of Infectious Diseases, Department of Pediatrics, NHO Shimoshizu National Hospital
6. Department of Emergency and Critical Care Medicine, St. Marianna University Yokohama Seibu Hospital