Koch’s time for COVID-19 and the other major epidemics of the 21st century

Koch’s postulates are classical medical standard followed by researchers all over the world to identify a new pathogen for an emerging infectious disease (EID). In this article, we put forward a new concept of Koch’s time for a new pathogen (KTNP), which stands for the time from the first case of attention of an EID to the first complete genome of the new pathogen in a public domain, to quantify the response of EIDs. Shortening KTNP expedites development of detection kits and/or devices world-wide. The KTNP of five EIDs occurred in this century are calculated respectively. The results demonstrated that KTNP is continuously shortening and Koch’s time for COVID-19 is 15 days.