So far, the only two cases of Ebola being contracted in the United States occurred when two nurses cared for a patient in Dallas. That patient later died. All other cases, so far, in the United States originated outside the country, most often in people coming from countries in West Africa.
Please note that the single patient who died, Thomas Eric Duncan, went to a hospital on September 25th, the day after he started running a fever. Duncan was sent home the same day. On September 28th, three days later, Duncan returned to the hospital when his fever did not break. It was not until September 30th that tests proved Duncan had the disease. Duncan was already at high risk of transmission when he checked into hospital. On October 8th, nine days after being diagnosed, Duncan died.
Note that Duncan was infectious from the time he began running a fever until the day he died. None of the forty-three other persons Duncan had contact with, other than the two nurses mentioned below, have contracted Ebola.
Protective gear was not worn by health workers until Duncan's diagnosis was made. This means Duncan was infectious and interacting with unprotected hospital personnel for two and a half days.
Nina Pham, one of the nurses who treated Duncan, tested positive for EVD* eleven days after Duncan was diagnosed. Amber Vinson, another nurse who cared for Duncan, was diagnosed with EVD sixteen days after Duncan was diagnosed.
Both nurses have now been declared virus free.
Dr. Martin Salia was admitted to the Nebraska Medical Center on the 15th of November 2014 and died on the 17th of November that same year. Hospital reports indicate that Dr. Salia was already in critical condition upon admission to the hospital.
This means, so far, that the mortality rate of EVD in the U.S. is near 20%, with eight survivors out of ten infections.