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

ABSTRACT

BackgroundCOVID-19 infectiousness might differ by infection location. Nevertheless, no such study of infectiousness has been reported. ObjectThe study objective was estimation of the reproduction number by infection location. MethodPatients who infected no one were ignored because their reliability might be lower than that of patients who infected more than one person. On the assumption that the histogram follows an exponential distribution, we estimated the reproduction number from the histogram of the number of people infected by the same patient. ResultsNight entertainment venues showed the greatest infectiousness, followed by facilities for elderly people and hospitals. Nursery schools and workplaces were followed by homes, with the lowest infectiousness. Discussion and ConclusionCountermeasures under the second declaration of emergency status targeted restaurants. However, infectiousness at restaurants was not high. Comparable to those of universities and karaoke, and not significantly different from homes the least infectious location studied.