AlHijjah 23, 1435, Oct 17, 2014, SPA -- First tests on a passenger who landed in Madrid with suspected Ebola symptoms found no trace of the virus Friday, a government source said. A second test within three days is required to confirm an Ebola-free status. Spanish authorities isolated the Air France plane at Madrid airport for more than two hours Thursday amid concerns over the symptoms of one of the passengers who had travelled from Nigeria to Paris and later took the connecting flight to Madrid. He was brought to an isolation ward at Madrid's Carlos III hospital, dpa reported. In another suspected case on the Spanish island of Tenerife, hospital authorities quarantined a health worker who developed symptoms after returning from Sierra Leone. The tests on the man were pending. The World Health Organization (WHO) said Thursday it was reviewing Ebola preparedness in 15 African countries considered particularly vulnerable to the spread of the disease.