The Cruise Ship is the most bizarre (I mean that in the truest sense of the word) but also complex conundrum in modern infectious diseases I've come across from a public health perspective.

It is NOT analogous to the Wuhan evacuees. The maximum "point prevalence" from the evacuees anywhere was about 2%, and was typically less than 0.5%. That would translate to about 15-75 of the pax on the ship having the infection...strict isolation of those individuals is manageable in a healthcare setting. But now, they have about 5% point prevalence, and rising. Because of the way this has been handled (hindsight and all), it's now becoming impossible to get the people off, because you have extreme risk of cross-infection. BUT, having said that, I would say it's highly unlikely that all 175 pax were already infected a week ago...that just doesn't seem right given as already pointed out, the majority show symptoms within a few days, and all symptomatic pax were tested a week ago.

At some point, Japan has to bite the bullet: perhaps evac to the US military base in Okinawa (do they still have a presence there), cohort as best they can the confirmed/ probable/ probably not. It's clear the infection control procedures on board the ship have completely failed at this point...unless they act in the next day or two, this may become a humanitarian disaster...there's already one in Hubei, but most Western folks don't care about that...these are moneyed westerners, and that becomes a political liability.

Re: the new clinical case definition...at some point, it becomes pointless to try and diagnose everyone by RT-PCR: that happened in 2009 with H1N1 way before we had reached this point. But the only concern I have is that with the Draconian cohorting policies in place, this may actually cause people with bacterial or influenza-caused pneumonia to be newly infected by SARS-CoV-2 (!!!), which would probably tip them into a pre-morbid state.

tb

ETA: As also already mentioned, even with the revised clinical definition, what's happening in Hubei is clearly very different to what's happening outside Hubei. And clearly what's happening in Hubei is not good...We know from Singapore that up to 15% of infected people can have severe disease, so this is a serious infection, but the mortality rate in Hubei is just plain worrisome, and seems to be out of whack with anything we're seeing elsewhere. There's also the hint of containment in non-Hubei China (although internationally it's mostly a black hole), but although the RT-PCR confirmed case numbers are still declining in Hubei, it's still way off-trend compared with anywhere except Diamond Princess, which is clearly the biggest hotspot on the planet right now (but with a fixed upper bound until they let people off the ship).