Are they contagious even when asymptomatic? That would be truly frightening.
Yes, it’s contagious when asymptomatic. That’s been known since early January. Meanwhile, non-Chinese were debating whether SARS2 spreads person-to-person as late as last week.
China is underreporting deaths by 10-100x, and cases by 5-25 times. Notice that the number of countries reporting at least one death has doubled this week.
If you naively divide reported deaths by confirmed cases in China, that number has been 2.1% every day for a month. If new cases were slowing down, that number would rise to 4-12%. But Chinese reporting makes analysis of the daily numbers a case of GIGO (garbage in, garbage out).
U.S. numbers of cases are also underreported, because we are not testing cases unless there is an established Chinese connection. By the time U.S. authorities get on this, these united states numbers will be almost as bad as China’s true numbers, and definitely worse than China’s reported numbers.
Worst for last: this was not designed as a bio-weapon. But anyone with access to CRSP technology can do this. And SARS2 now has Cas9 in its genome.
“Are they contagious even when asymptomatic?”
Yes. (Chinese gal infecting Germans is one example)
So having 50% of the folks as “Typhoid Mary” is not a good thing.