DAKAR, Senegal (AP) _ The World Health Organization says tests on samples from the 17-year-old boy who died from Ebola nearly two weeks ago in Liberia show the virus is genetically similar to viruses that infected many people in the area more than six months ago.

The organization said Friday that genetic sequencing suggests it is unlikely the virus was caught from travel to infected areas of Guinea or Sierra Leone, or from an animal.

Dr. Margaret Harris, WHO spokeswoman, said 149 people have been identified as having contact with the teen. She said one possible mode of transmission could have been sexual and tests will help track the possible cause.

The total number of new confirmed cases in Liberia is now five, including the teen who died on June 28.