Estimating SARS-CoV-2 reproduction number by infection location in Japan

Background: Infectiousness of COVID-19 by infected place might be different. However, studies of such infectiousness have not been reported. Object: The object of this study was estimation of reproduction numbers by infected place. Method: We ignore patients who infected no one because their reliability might be lower than that of patients who infected more than one person. We estimated the reproduction number from the histogram of the number of the infected people by the same patient, assuming that the histogram follows an exponential distribution. Results: Entertainment at night was the highest and facility for elderly people and hospital followed. Home was the lowest and nursery school and workplace followed. Discussion and Conclusion: The counter measure under the second emergency status declaration targeted restaurant. However, infectiousness at restaurant was not so high and comparable as university or karaoke and not significantly difference from at home which is the lowest infectiousness place.