The New York Times – At least 18 cases have been treated in Europe and the United States. Many involved health and aid workers who contracted Ebola in West Africa and were transported back to their home country for treatment. A doctor in New York City, who had recently been working with Doctors Without Borders in Guinea, tested positive for the Ebola virus on Oct. 23. Cases shown below are compiled from reports by the C.D.C., the World Health Organization, Doctors Without Borders and other official agencies.