Twitter exploded with questions about the deadly virus, which according to the World Health Organization is believed to have killed hundreds in four West African nations. And with reaction to news that two infected Americans would soon be on their way back to the United States.
"Why are they doing this?" Robin Hunter asked in a post on Twitter.
While U.S. officials have remained mum on the issue, a source told CNN that a medical charter flight left from Cartersville, Georgia, on Thursday evening.
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A CNN crew saw the plane depart shortly after 5 p.m. ET. The plane matched the description provided by the source, who spoke on condition of anonymity.
It was not immediately known when the two Americans -- identified by the source as Dr. Kent Brantly and Nancy Writebol -- would arrive in the United States, or where the plane would land.
At least one of the two will be taken to a hospital at Emory University, near the headquarters of the U.S. Centers for Disease Control and Prevention in Atlanta, hospital officials told CNN's Dr. Sanjay Gupta.