(AP) An American doctor exposed to the Ebola virus after a needle stick in Sierra Leone has been released from isolation and sent home. The doctor had been kept in isolation at the National Institutes of Health in Bethesda since Sept. 28 out of an abundance of caution. The NIH said Tuesday the aid worker briefly had a fever, but it was not connected to Ebola. He has no fever. The NIH says the doctor will remain in his home to complete a 21-day period of observation, and check his temperature twice a day.