1. Department of Inspection, Infectious Diseases Hospital of Jinan, Jinan, Shandong 250021, P.R. China
2. Department of Pediatrics, Tianjin Nankai Hospital, Tianjin Medical University, Tianjin 300100, P.R. China
3. Department of Inspection, Jinan Blood Center, Jinan, Shandong 250001, P.R. China