After a series of laboratory blunders involving a number of deadly biological agents, the US Centers for Disease Control and Prevention (CDC) has temporarily suspended activity of its anthrax and flu labs.

On July 11, federal health officials revealed details of another health and safety breach at a government laboratory involving smallpox.

In March, scientists operating within a high-security influenza laboratory had allegedly dispatched samples of a harmful strain of bird flu to workers at the U.S. Department of Agriculture. The incident occurred after scientists contaminated a common and benign flu strain (H9N2) with a deadly form of bird flu (H5N1). Realizing the sample was harmful, USDA workers took the appropriate precautions and informed the CDC of the error.

In light of recent safety concerns, the CDC has introduced a moratorium on the transportation of hazardous, biological samples and inactivated specimens within and around the agency’s high security laboratories. According to CDC Director Tom Frieden, those individuals failing to comply with safety protocols, or who do not report serious errors, will face disciplinary action.

The anthrax and flu laboratories will be shut down until new health and safety policies are introduced.

Frieden recently indicated he was “astonished” and angered by the breaches. “They should never have happened. I’m upset, I’m angry, I’ve lost sleep over this, and I’m working on it until the issue is resolved,” explained Frieden.