Emerging Infectious Diseases (Mar 2021)

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
https://doi.org/10.3201/eid2703.203882
Journal volume & issue
Vol. 27, no. 3
pp. 915 – 918

Abstract

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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%.

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