2022-08-29 Press Release

Professor Shingo Iwami (Graduate School of Science, Nagoya University / Visiting Scientist, iTHEMS), in collaboration with Assistant Professor Keisuke Ejima (Indiana University, USA), has developed a new simulator (computer simulation) to verify when to end isolation of persons infected with a novel coronavirus (COVID-19) through antigen testing.

This will allow us to propose a flexible and safe isolation strategy that can terminate isolation of COVID-19-infected patients as early as possible with negative results of a predetermined number of antigen tests.

Isolation of infected patients is an important means of preventing the spread of infection. While prolonged isolation reduces the risk of secondary infection, it also places various burdens on the person being isolated and the society that supports them.

Using the simulator they have developed, the research group has successfully calculated "the risk of (prematurely) terminating isolation of infectious patients" and "the duration of unnecessary isolation of patients who are no longer infectious (the burden associated with isolation)." As a result, we are now able to propose an appropriate isolation strategy that takes into account individual differences and uses antigen testing to simultaneously reduce risk and burden. As we enter the era of with-colonization, in which social activities are resumed and maintained while infection prevention measures are thoroughly implemented, the successful use of antigen testing will allow for the safe implementation of educational and social activities.

In contrast to the current situation where different isolation standards based on clinical and epidemiological data and empirical rules are adopted in different countries, this study is expected to contribute to the establishment of flexible isolation guidelines based on mathematical models, which are required not only in Japan but also worldwide.

For more details, please visit the Nagoya University research results dissemination site from the related link.


  1. Yong Dam Jeong, Keisuke Ejima, Kwang Su Kim, Woo Joohyeon, Shoya Iwanami, Yasuhisa Fujita, Il Hyo Jung, Kazuyuki Aihara, Kenji Shibuya, Shingo Iwami, Ana I. Bento and Marco Ajelli, Designing isolation guidelines for COVID-19 patients with rapid antigen tests, Nature Communications 13, 4910 (2022), doi: 10.1038/s41467-022-32663-9

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