I fear that if it is the flu virus, we are already doomed - because they showed symtoms only a day or two after arriving - and the flu generally takes 14-21 days to really get going - meaning they were already infected when they left.
So if I lived in Texas...
From my extensive flu readings some years ago, after contracting flu symptoms generally show up in 24-48 hours, and that is my experience as well.
How many people does the. Flu kill a year?