Global Health & Medicine
Online ISSN : 2434-9194
Print ISSN : 2434-9186
A single-center descriptive study of untraced sources of infection among new cases of coronavirus disease in Tokyo, Japan
Sayaka HikidaShinichiro MoriokaNaoki FujiiTaichi TajimaYuriko TerayamaYuriko SugiuraMasahiro IshikaneJin TakasakiMasayuki HojoNorio Ohmagari
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2021 Volume 3 Issue 4 Pages 236-239


We investigated possible sources of newly infected patients with coronavirus disease (COVID-19) after the fourth wave in order to explore unknown sources. Retrospective chart review on all the confirmed patients with COVID-19 admitted to the National Center for Global Health and Medicine (NCGM) in Tokyo, Japan was conducted from May 22 through June 29, 2021. Among the 22 participants, 14 (64%) had a history of known high-risk infection behaviors. Of those, 12 reported that their activities involved eating and drinking. In addition, there were 24 high-risk situations, of those, 21 (88%) were related to indoor dining, and masks were not worn in 22 situations (92%). New source of infection has not been identified. In situations with a high known risk of infection, many cases were related to eating and drinking, and insufficient use of masks was evident. Raising risk awareness on infection prevention and control of COVID-19 is urgently needed.

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© 2021 National Center for Global Health and Medicine
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