US lab worker possibly exposed to Ebola showing no symptoms, says CDC

A scientist who may have accidentally been exposed to the deadly Ebola virus last month while working in a lab at the US Centers for Disease Control and Prevention in Atlanta is showing no signs of the illness, the agency's director said on Friday.

CDC Director Dr. Thomas Frieden said in a conference call that the agency is still investigating the apparent mix-up that occurred Dec. 22 in which a scientist in a high-level biosafety lab mistakenly sent a sample of live virus to a less secure lab in which scientists were not wearing proper protection.

The technician is being monitored for signs of infection for a total of 21 days, the disease's incubation period. Frieden said the CDC will issue a report on the incident by the end of the month.

The error follows two high-profile cases of mishandled samples of anthrax and avian influenza at the CDC earlier this year that called into question safety practices at the agency.