The U.S. Centers For Disease Control and Prevention said on Thursday it was investigating how one of its lab workers, recently diagnosed with salmonella infection, may have acquired the disease while working at a pathogen lab.
The agency said initial tests indicated the worker was infected with a strain of salmonella that matched the strain being worked on in the lab.
"The worker is well and back at the CDC and, based on what we know now, no other staff were exposed ... there was no release outside the laboratory," the agency said.
The CDC will investigate to see if additional safeguards were needed to prevent exposures when performing such procedures in the future.
The CDC has been at the center of a series of lab mishaps in the last couple of years despite taking stringent measures to enhance safety.
One lab worker inadvertently risked contracting Ebola in 2014 while working with the live virus that was supposed to have been inactivated, or killed.
In another incident, scientists unknowingly sent potentially live anthrax to a lower-security laboratory and in still another, a deadly form of bird flu was sent to an external agency's lab. (https://reut.rs/1VbQLJV)