He was able to get so sick because his first Ebola screen cleared him.
Apparently, getting cleared means they don’t bother to screen you again for, like, a week. Even if you continue to show symptoms.
The radio reports I have heard today make no mention of the false positive that killed him.
I wrote “false positive” above, but I meant “false negative”, I think.
Salia, a Sierra Leone citizen who was a permanent resident of the U.S. and lived in Maryland, first showed Ebola symptoms on Nov. 6 but tested negative for the virus. He eventually tested positive on Monday. Smith called the initial test results "not unusual."
http://www.foxnews.com/health/2014/11/17/surgeon-who-contracted-ebola-virus-in-sierra-leone-dies-at-nebraska-hospital/
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This was the whole point with quarantining nurse Kaci Hickox.
Even though no virus showed up in Hickox's initial blood work, the Maine CDC official felt that she had been tested for Ebola too early......that it was possible the virus could still show up during the period of incubation. The Maine CDC official was especially concerned after learning that Hickox's room mate tested positive for Ebola.