Experience to date in the US seems to indicate that the CDC and MSF (Doctors Without Borders) has been right all along. You are highly unlikely to get Ebola from someone who is in the early, pre-symptomatic stages of infection. So far the only people who been infected with ebola from another, were the two nurses in Dallas who were treating Mr. Duncan, when he was in an advanced stage of the disease. Even those who lived in the same apartment with him when he was starting to get sick have not become infected.