1. Department of Pediatrics Yamaguchi University Graduate School of Medicine Ube Japan
2. Department of Pathology Yamaguchi University Graduate School of Medicine Ube Japan
3. Department of Pathology National Institute of Infectious Diseases Shinjuku‐ku Japan
4. Yamaguchi Prefectural Institute of Public Health and Environment Yamaguchi Japan
5. Akihabara Atsuta Clinic Chiyoda‐ku Japan