Familial Clusters of Coronavirus Disease in 10 Prefectures, Japan, February-May 2020

Reiko Miyahara; Naho Tsuchiya; Ikkoh Yasuda; Yura K Ko; Yuki Furuse; Eiichiro Sando; Shohei Nagata; Tadatsugu Imamura; Mayuko Saito; Konosuke Morimoto; Takeaki Imamura; Yugo Shobugawa; Hiroshi Nishiura; Motoi Suzuki; Hitoshi Oshitani

doi:10.3201/eid2703.203882

Familial Clusters of Coronavirus Disease in 10 Prefectures, Japan, February-May 2020

Emerg Infect Dis. 2021 Mar;27(3):915-918. doi: 10.3201/eid2703.203882.

Authors

Reiko Miyahara, Naho Tsuchiya, Ikkoh Yasuda, Yura K Ko, Yuki Furuse, Eiichiro Sando, Shohei Nagata, Tadatsugu Imamura, Mayuko Saito, Konosuke Morimoto, Takeaki Imamura, Yugo Shobugawa, Hiroshi Nishiura, Motoi Suzuki, Hitoshi Oshitani

Abstract

The overall coronavirus disease secondary attack rate (SAR) in family members was 19.0% in 10 prefectures of Japan during February 22-May 31, 2020. The SAR was lower for primary cases diagnosed early, within 2 days after symptom onset. The SAR of asymptomatic primary cases was 11.8%.

Keywords: COVID-19; Japan; SARS-CoV-2; coronavirus disease; familial clusters; prefectures; respiratory infections; severe acute respiratory syndrome coronavirus 2; viruses.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Asymptomatic Infections / epidemiology
COVID-19 / diagnosis
COVID-19 / epidemiology*
COVID-19 / transmission
Contact Tracing / statistics & numerical data
Family*
Female
Humans
Incidence
Japan / epidemiology
Male
SARS-CoV-2 / isolation & purification
Time Factors