But even then, she said, the U.S. would still have a handle on the outbreak, as "people are aggressively looking for this," and the disease makes someone so sick that they would be unlikely to avoid medical care.
The major tool in the public health arsenal for controlling an outbreak is contact tracing, experts said. This involves interviewing those with infections to ascertain with whom they have had close interactions, and then monitoring those people for 21 days. For a disease like Ebola, Spicehandler said, this process is relatively easy given that it cannot be transmitted just from proximity. The CDC has a helpful infographic on contact tracing here.
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The number of people that the CDC and local officials will consider significantly at risk of having contracted the disease is relatively small, as it would require bodily fluid contact during the few days that the patient was symptomatic and not yet hospitalized, said JoEllen Harris, director of the Johns Hopkins Health System's Epidemiology and Infection Prevention Program.
This would include, for example, someone who had drawn blood from the man without wearing protective gloves, she said.
"Sneezing doesn't count, this is not a respiratory infection," Shaffner explained.