The patient is being isolated and authorities are contact tracing. PARIS, June 24 (Reuters) - A doctor returning from a humanitarian mission in Congo has tested positive for Ebola, the country’s first case of the virus during the current outbreak, the health ministry said on Wednesday. The patient is being isolated and authorities are contact tracing, the ministry said in a statement, adding that the risk for the general European population was low. Congo’s Ebola outbreak, which has infected