A laboratory operated by the Centers for Disease Control and Prevention (CDC) had its permit suspended for three years for violating federal safety rules in its handling of bioterror pathogens, according to a report published Tuesday.

In addition, USA Today reported that the CDC's own labs have been referred for federal action six times because of serious or repeated lapses in their handling of viruses, bacteria and toxins that are heavily regulated due to their potential use as bioweapons.

The CDC and U.S. Department of Agriculture (USDA) co-run the Federal Select Agent Program, which regulates labs working with bioterror pathogens, such as anthrax, smallpox and plague. Only five labs have been suspended from the program since 2003, while just five others have faced repeated referrals for federal enforcement actions, USA Today reported.

The identities of the suspended labs have been kept secret by the CDC and the USDA.

In a statement to USA Today, the CDC confirmed that its own labs had been referred to the Department of Health and Human Services' Inspector General six times since 2003. The agency said three of the referrals involved sending improperly killed pathogens to entities not approved to receive them. Two others related to the discovery of select agent pathogens in un-registered spaces, while the other referral involved inventory and oversight concerns.

"None of these violations resulted in a risk to the public or illness in laboratory workers," the CDC said. The statement added that one referred case remains open, though it did not specify what that was. The other cases were closed after the agency "demonstrated enhanced procedures to prevent future occurrence." The CDC did not say when the referral cases were opened or closed.

The CDC also said the permit suspension took place in 2007 and involved a lead scientist and the labs associated with that scientist's research into the Japanese encephalitis virus at the agency complex in Fort Collins, Colo. The USDA found that the scientist's research was not in compliance with the Federal Select Agent program's requirements.

The virus samples were either destroyed or transferred to another facility that was licensed to receive them and the permit was restored in 2010.

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