CDC investigates pathogens found in Department of Defense labs

The CDC confirms it is investigating possible mishandling of several samples of pathogens associated with bioterrorism -- including plague, possible live strains of anthrax and two kinds of equine encephalitis, a virus derived from horses that causes swelling of the brain -- that were discovered during routine inspections on August 17.

They were found at four labs -- three in Maryland and one in Utah -- that are part of the Department of Defense's "Critical Reagents Program." The potential issues involved transfers that may have been improperly documented between DoD facilities.

"The CDC investigation is trying to determine whether there are record-keeping discrepancies and quality management issues or violations in the unapproved shipment of select agents," the CDC said in a email statement to CBS News. "CDC is working to track shipments and confirm the safety of those working with these materials. At this time, there is nothing to suggest risk to the health of workers or the general public."

On September 2, the Secretary of the Army issued a memo directing a safety review of all DoD labs involved in the production, shipment or handling of materials in the Biological Select Agent Toxin (BSAT) Biosafety Program.

According to the memo, a moratorium put in place on July 23 halting any handling of inactivated anthrax continues.

The moratorium has also been expanded to include a halt to any activity with substances in the BSAT program, at all four facilities: Dugway Proving Ground in Utah; and Maryland's Edgewood Chemical and Biological Center, U.S. Army Medical Research Institute of Infectious Diseases, and the Naval Medical Research Center Biological Defense Research Directorate.

According to the CDC, the plague bacteria (Yersinia Pestis) discovered was tested, but investigators now believe it was properly packaged and labeled that the bacteria was not live.

These inspections are part of ongoing investigations into the handling of bioterrorism agents since a mishap in May in which anthrax that was supposed to have been deactivated, but remained live, was accidentally shipped to 17 states over a two-month period from Dugway Proving Ground.

Scientists conducting ongoing research using these pathogens can receive waivers to continue.