학술논문
Impact of COVID-19 and Closed Transmission of SARS-CoV-2 during the First Wave in Toyama Prefecture, Japan, March 30 to May 18, 2020.
Document Type
Academic Journal
Author
Tamura K; Department of Research Planning, Toyama Institute of Health, Japan.; Inasaki N; Department of Virology, Toyama Institute of Health, Japan.; Itamochi M; Department of Virology, Toyama Institute of Health, Japan.; Saga Y; Department of Virology, Toyama Institute of Health, Japan.; Shimada T; Department of Virology, Toyama Institute of Health, Japan.; Yazawa S; Department of Virology, Toyama Institute of Health, Japan.; Sasajima H; Toyama Institute of Health, Japan.; Kawashiri C; Toyama Institute of Health, Japan.; Yamazaki E; Osaka Institute of Public Health, Japan.; Ichikawa T; Toyama Red Cross Hospital, Japan.; Kaya H; Department of Infectious Disease, Toyama Prefectural Central Hospital, Japan.; Yamamoto Y; Department of Clinical Infectious Diseases, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan.; Morinaga Y; Department of Microbiology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan.; Yamashiro S; Department of Internal Medicine, Asahi General Hospital, Japan.; Nomura S; Toyama City Hospital, Japan.; Takeda S; Kurobe City Hospital, Japan.; Ito H; Takaoka City Hospital, Japan.; Hirota K; Tonami General Hospital, Japan.; Horie Y; Saiseikai Toyama Hospital, Japan.; Hirano N; Toyama Rosai Hospital, Japan.; Sekizuka T; Pathogen Genomics Center, National Institute of Infectious Diseases, Japan.; Kuroda M; Pathogen Genomics Center, National Institute of Infectious Diseases, Japan.; Tani H; Department of Virology, Toyama Institute of Health, Japan.; Oishi K; Toyama Institute of Health, Japan.
Source
Publisher: National Institute of Infectious Diseases Country of Publication: Japan NLM ID: 100893704 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1884-2836 (Electronic) Linking ISSN: 13446304 NLM ISO Abbreviation: Jpn J Infect Dis Subsets: MEDLINE
Subject
Language
English
Abstract
We studied 226 patients in Toyama Prefecture who were notified of COVID-19 during the first wave between March 30 and May 18, 2020. Of the 226 patients, 22 (9.7%) died, most (95%) of whom were aged ≥65 years. A large cluster comprising 59 patients (41 residents and 18 staff members) was identified in a nursing home on April 17. No deaths occurred among staff members; however, 12 of the 41 residents (29%) died. Although the threshold cycle (Ct) values were significantly lower in the 20-64 and ≥65 years age groups than in the <20 years age group, no correlation was found between the Ct values and severity, fatal outcome, or secondary infection. The haplotype network of 145 SARS-CoV-2 isolates (64%) from 226 patients was analyzed. The viral genomes of the case groups differed by less than five nucleotide bases. These data suggest that the SARS-CoV-2 strains, which were initially introduced into Toyama Prefecture in late March and early April 2020, and their closely related strains, identified as lineage B.1.1, circulated during the first wave. The reduced inter-prefectural mobility of local residents may support the lack of strain diversity in SARS-CoV-2 during the first wave of the state of emergency.