Photo credit: European Commission.

The Centers for Disease Control and Prevention in Atlanta were supposed to send a relatively mild form of avian flu to the Southeastern Poultry Research Laboratory in Athens for study.

Instead, in an incident officials disclosed Friday, what the CDC actually shipped was an H9N2 sample contaminated with the far more dangerous H5N1 virus, which has killed 375 people since 2002.

"We were the ones who identified that the sample was contaminated, and we notified the CDC accordingly," said Sandy Miller Hays, spokeswoman for the USDA's Agricultural Research Service.

The SPRL is a Bio-Safety Level 3 lab equipped to handle potentially deadly pathogens, including those that are zoonotic (able to jump from animals to humans). Pathogens studied at BSL 3 labs include the plague, SARS, rabies and West Nile. So even though the avian flu sample wasn't the strain expected, neither lab employees nor the public were in any danger.

In a more serious incident last month, "at least 62 CDC employees may have been exposed to live anthrax bacteria after potentially infectious samples were sent to laboratories unequipped to handle them," according to the New York Times. And the National Institute of Health recently discovered two 60-year-old vials of smallpox containing live viruses.

“These events revealed totally unacceptable behavior,” CDC director Thomas Frieden said. “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.”

The CDC has shuttered its anthrax and flu labs until new procedures are implemented.

Still, it kinda makes you glad we didn't get NBAF.