The first case of Ebola has been confirmed in Senegal, according to news reports, making it the fifth West African nation to be affected by the current outbreak.
The country's health minister said the infected person is a university student from Guinea who sought treatment at a hospital in Senegal's capital of Dakar, The Associated Press reported.
Senegal had earlier closed its border with Guinea in an attempt to stop the spread.
The WHO estimates the outbreak could reach 20,000 cases of the virus. The organization's roadmap, released Thursday, calls for stopping Ebola transmission within six to nine months through a series of measures, such as screening at airports and stopping nonessential travel to hard-hit areas.
The U.S. National Institutes of Health announced on Thursday it will start testing a vaccine on humans next week. It says it does not know when the vaccine will be available, though, and that prevention measures are the best solution to the outbreak in Africa this year.