A patient who was being tested for Ebola while at the Hospital of the University of Pennsylvania in Philadelphia does not have the virus, according to an article on the NBC New website.
The situation came after another case in Nebraska last month, when an American man was monitored for possible exposure to Ebola following a trip to Africa.
He was released after the required 21-day monitoring period when it was determined he didn't have any symptoms.
Since August, the Congo has been gripped by an Ebola outbreak that has killed at least 430 people and been confirmed in more than 730 cases, according to figures released this week by the World Health Organization.