The incubation period of an infectious disease is very important for control of the disease but estimating the period is not easy because the date of infection is not easy to identify. We report accurate incubation period distributions by examining cases in the cluster generated in live-houses in Osaka, Japan with known infection events. The distribution of the latent period was also estimated. The modes of incubation and latent periods of COVID-19 in Japan were 4.1 days and 3.3 days, respectively. The mode of the delay time from the onset to reporting was estimated to be 4.7 days, telling that the effects of interventions show up in the number of infections two weeks later after the measures.
Incubation period of COVID-19 in the live-house cluster of accurately known infection events and delay time from symptom onset of public reporting observed in cases in Osaka, Japan