A patient who was being tested Wednesday for Ebola while at the Hospital of the University of Pennsylvania in Philadelphia does not have the virus, officials said.

Preliminary testing initially ruled out Ebola, but an evaluation was done out of "an abundance of caution," said Dr. P.J. Brennan, Penn Medicine's chief medical officer.

The hospital did not provide more information about the patient or the circumstances for their treatment, but said that testing is needed when symptoms "suggest a serious disease, particularly involving patients who have traveled overseas."

The scare follows 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.

Ebola is an extremely deadly virus that causes a hemorrhagic fever and has no specific proven cure. It is named after a river in the Democratic Republic of Congo, where it was first discovered in 1976.

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.

A major Ebola epidemic that began in 2014 and lasted through 2016 affected the western African nations of Sierra Leone, Liberia and Guinea, and led to the deaths of more than 11,300 people.