(NBC News) The Centers for Disease Control and Prevention has issued a shipping moratorium on all samples of biological materials from some of its highest security level labs until an intense safety review is conducted.
The move comes after an internal investigation at the CDC revealed several serious errors at labs historically considered world-class in their safety precautions.
"I'm disappointed by what happened and frankly, I'm angry about it," CDC Director Dr. Tom Frieden said during a press briefing Friday.
Frieden addressed recent incidents, starting with the anthrax scare that potentially exposed at least 80 CDC workers.
"The scientists failed to follow a scientifically derived and reviewed protocol that would have assured that anthrax was inactivated and that the material was confirmed to be sterile before it ever left the lab. That should have happened and it didn't," he said.
None of the workers has fallen ill, but that lab is now closed. In a separate incident, workers accidentally sent a sample of highly infectious bird flu to an outside lab.
This week another government health agency discovered decades-old vials of what we now know are viable forms of smallpox.
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