The guy in Dallas - apparently the woman he helped (the pregnant woman in Liberia) whom spread it to a larger number of people was believed to be sick *with pregnancy related complications*
They didn't think she was sick with Ebola.
They didn't think the guy was sick with it, either.
Detection is the essential and missing element as is adequate purging (like the whole 'we bleached' fiasco - where the CDC said they weren't adequately prepared for the cleanup).
So what is it that will tip healthcare provides off to someone *having Ebola* and not just a stomach bug?