Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Jul;20(7):715-719.
doi: 10.1111/ggi.13973.

Clusters of COVID-19 in long-term care hospitals and facilities in Japan from 16 January to 9 May 2020

Osamu Iritani  1 , Tazuo Okuno  1 , Daisuke Hama  1 , Asami Kane  1 , Kumie Kodera  1 , Kozue Morigaki  1 , Toshio Terai  1 , Norie Maeno  1 , Shigeto Morimoto  1
Affiliations

Clusters of COVID-19 in long-term care hospitals and facilities in Japan from 16 January to 9 May 2020

Osamu Iritani et al. Geriatr Gerontol Int. 2020 Jul.

Abstract

Aim: To clarify the association of cluster number and size of coronavirus disease 2019 (COVID-19) in long-term care (LTC) hospitals/facilities, general medical/welfare facilities and non-medical/welfare facilities with morbidity and mortality in 47 prefectures during 16 January to 9 May 2020 in Japan.

Methods: Information on COVID-19 clusters (n ≥2), and morbidity and mortality of COVID-19 was collected.

Results: A total of 381 clusters with 3786 infected cases were collected, accounting for 23.9% of 15 852 cumulated cases on 9 May 2020. Although the cluster number (/107 subjects) in LTC hospitals/facilities was significantly smaller compared with those in the other two groups, the cluster size in LTC hospitals/facilities was significantly larger than that in non-medical/welfare facilities. Cluster numbers in general medical/welfare facilities and in non-medical/welfare facilities were significantly positively correlated with morbidity (/105 ), indicating relatively early identification of clusters in these facilities. Unlike in these facilities, cluster size in LTC hospitals/facilities was significantly positively correlated with morbidity, indicating that clusters in LTC hospitals/facilities were finally identified after already having grown to a large size in areas where infection was prevalent. Multivariate logistic regression analysis showed that both cluster number and cluster size only in LTC hospitals/facilities were independently associated with higher mortality (≥median 0.64/105 subjects) after adjustment.

Conclusions: Preventive efforts against COVID-19 outbreaks even at the early phase of the epidemic are critically important in LTC hospitals/facilities, as both the larger number and size of clusters only in LTC hospitals/facilities were independently linked to higher mortality in prefectures in Japan. Geriatr Gerontol Int 2020; 20: 715-719.

Keywords: COVID-19; cluster; long-term care facility; morbidity; mortality.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Daily COVID‐19 cases reported in Japan from 16 January to 9 May 2020. Derived from the website of the Japan Broadcasting Corporation (NHK).
Figure 2
Figure 2
Associations of cluster number (/107 subjects) with (a) morbidity (/105 subjects) and (b) mortality (/105 subjects) in prefectures in Japan. Red circles, clusters in long‐term care hospitals/facilities; green squares, clusters in general medical/welfare facilities; blue triangles, clusters in non‐medical/welfare facilities.
Figure 3
Figure 3
Associations of cluster size with (a) morbidity (/105 subjects) and (b) mortality (/105 subjects) in prefectures in Japan. Red circles, clusters in long‐term care hospitals/facilities; green squares, clusters in general medical/welfare facilities; blue triangles, clusters in non‐medical/welfare facilities.
See this image and copyright information in PMC

References

    1. McMichael TM, Currie DW, Clark S et al. Epidemiology of Covid‐19 in a long‐term care facility in King County, Washington. N Engl J Med 2020; 382: 2005–2011. - PMC - PubMed
    1. Kamp J, Mathews AW. Coronavirus outbreaks spreading in nursing homes. Wall Street Journal. Available from: https://www.wsj.com/articles/coronavirus-outbreaks-spreading-in-nursing-...
    1. Georgia Department of Community Health . Long‐term care facility COVID‐19 report. Available from: https://dch.georgia.gov/announcemnent/2020-04-28/long-term-care-facility....
    1. Chidambaram P. State reporting of cases and deaths due to COVID‐19 in long‐term care facilities. Available from URL https://www.kff.org/medicaid/issue-brief/state-reporting-of-cases-and-de...
    1. Bensadoun, E (2020). “Nearly half of Canada's COVID‐19 deaths linked to long‐term care facilities: Tam”. Available from URL https://globalnews.ca/news/6811726/coronavirus-long-term-care-deaths-can...

MeSH terms