SARS-CoV-2/COVID-19 watcher

3) Control measures could be extremely effective in locations that have had time to prepare. Maybe in a few, but seems unlikely that is the case in all, especially countries with stretched health systems.

4) Seasonal factors could be much more powerful at reducing transmission than we currently expect. That doesn't help the Southern hemisphere, and is not consistent with behavior in China (preprint in queue from @MauSantillana et al.)

So that's my reasoning. It is as tight as I can make it and is an effort to use the science as we have it to make our best estimate about the future. Predictions can be wrong and I very much hope this is, but better to be prepared.

Next question is what to do. While we have countable numbers of cases outside China, tracing, counting, trying to stop onward transmission one case at a time will help to buy time for those populations and on the hope that mitigating factors above hold, could maybe buy a lot

Buying time matters in order to get supplies, test treatments, progress on vaccine development, and learn from the experiences of those who are currently battling this virus. This may include travel restrictons and efforts to make sure returnees don't transmit

at which point will have to shift to mitigation rather than containment, and we must make sure that restrictions on travel, quarantine, and the like do not outlast their usefulness -- they are costly to individuals, families and economies and shd only be used as long as justified

If there is widespread community transmission driven importantly by mild or asymptomatic cases -- still a big if -- then it will be like flu and control measures targeting cases should be relaxed in favor of general social distancing to reduce contacts in general.