Earlier quoted context omitted.
Have you got a link for the 24 days? The best I could find is that we're totally guessing things at this point. CDC says: > CDC believes at this time that symptoms of 2019-nCoV may appear in as few as 2 days or as long as 14 after exposure. This is based on what has been seen previously as the incubation period of MERS viruses.
Apologies, I'm not sure if I misremembered, misattributed, or if that was an actual previous estimate from WHO. Everything I can find now seems to be around 14 days, with the Japanese govt using 16 as a lower bound for the cruise ship. I swear WHO was publishing 24 in a sitrep last week, maybe I just haven't found it yet. From the WHO Q&A page, > Current estimates of the incubation period range from 1-12.5 days with…
There was a paper that talked about 24 days but that was a single patient and the more likely scenario is that the person was wrong about the timing or got infected at a later time period.