Ebola Strain in New Liberia Cases Same as Virus From Last Year's Outbreak

The cases were confirmed weeks after the country was deemed Ebola-free.

Dr. Margaret Harris, a spokeswoman for WHO, said further tests are being done on people in the area to see if they had the virus in their body and didn’t know it.

"There are a considerable number of survivors. And we also know that it persists in certain bodily fluids, and that it can subsist for at least six months," Dr. Harris told the Associated Press.

She also said there’s a possibility that the transmission could have been sexual.

The Ebola outbreak was declared over by the WHO on May 9, but Liberia was under a 90 day “heightened surveillance” period when the new cases were discovered. Ebola is spread through bodily fluids between people in close contact. After patients recover they are no longer contagious, but virus particles have been found in semen months after an infection.

The Associated Press contributed to this report.