基本再生産数R0は、初期に2.2から2.7と推定されていたが、より多くのデータから4.7から6.6と推定、感染数は2.4日で倍増する
症状があるものだけの隔離とその接触者の追跡だけでは、効果的ではない可能性がある
ウイルスの感染阻止には初期の強力な管理手段が必要である
The novel coronavirus (2019-nCoV) is a recently emerged human pathogen that has spread widely since January 2020. Initially, the basic reproductive number, R0, was estimated to be 2.2 to 2.7. Here we provide a new estimate of this quantity. We collected extensive individual case reports and estimated key epidemiology parameters, including the incubation period. Integrating these estimates and high-resolution real-timehuman travel and infection data with mathematical models, we estimatedthat the number of infected individuals during early epidemic double every2.4days, and the R0 value is likely to be between 4.7 and 6.6. We further show that quarantine and contact tracing of symptomatic individuals alone may not be effective and early, strong control measures are needed to stop transmission of the virus.