NEW YORK (AP) — A Doctors Without Borders physician who recently returned to the city after treating Ebola patients in West Africa has tested positive for the virus, according to preliminary test results, city officials said Thursday. A law enforcement official and a City official received notification of the preliminary test results and told The Associated Press on the condition of anonymity but weren't authorized to discuss the case publicly before a Thursday night news conference. According to a rough timeline provided by city officials, Spencer's symptoms developed Wednesday, prompting him to isolate himself in his apartment. EMTs in full Ebola gear arrived and took him to Bellevue in an ambulance surrounded by police squad cars. Health officials say the chances of the average New Yorker contracting Ebola, which is spread through direct contact with the bodily fluids of an infected person, are slim. According to his Facebook page, he left for West Africa via Brussels in mid-September. Please support organizations that are sending support or personnel to West Africa, and help combat one of the worst public health and humanitarian disasters in recent history.