(Reuters) -New testing has found no evidence that the woman in Ivory Coast who tested positive earlier this month for Ebola actually had the virus, the World Health Organization (WHO) said on Tuesday.

“WHO considers that the patient did not have Ebola virus disease and further analysis on the cause of her illness is ongoing,” it said in a statement.

The positive result was found by a lab in Ivory Coast but subsequent testing in France came back negative, WHO said.

The initial test led Ivory Coast on Aug. 14 to declare its first Ebola outbreak in over 25 years. The woman had travelled to Ivory Coast’s commercial capital Abidjan from northern Guinea, hundreds of kilometers (miles) away.

More than 140 of the woman’s contact were listed in Guinea and Ivory Coast but none of them developed symptoms or tested positive, WHO said.

Ebola typically kills about half of those it infects, although vaccines and new treatments have proven highly effective in reducing fatality rates.

(Reporting by Aaron Ross; Editing by Leslie Adler and Sandra Maler)