The Center for Disease Control has closed its influenza and anthrax labs and halted sample shipments after two incidents in which avian flu virus was cross-contaminated and a number of researchers were exposed to anthrax. Today, the agency released the results of an investigation into a June anthrax scare, in which over 75 employees were accidentally exposed to live bacteria. While finalizing the report, it made an even more worrying finding: months before, in March, a sample of low-pathogenic avian flu virus had been accidentally contaminated with the highly pathogenic H5N1 virus and shipped to another lab. The contamination was confirmed in May, but news didn't make it up the CDC's chain of command until July 9th.

Neither incident, according to the report, appears to have caused lasting damage. No employees have been found infected with anthrax, and the avian flu sample was handled carefully enough before the discovery that it did not pose a safety risk. The samples of contaminated avian flu, meanwhile, have either been destroyed or are slated to be destroyed. But CDC director Thomas Frieden called the incidents "totally unacceptable." The anthrax laboratory has been closed since June 16th, and now, the influenza lab has followed; neither will reopen until the procedural problems have been solved. Moreover, it is immediately halting all movement of biological materials in laboratories that handle the most dangerous categories of samples.

The anthrax sample was meant to be sterilized before being sent to a lower-security poultry lab. But according to the report, it was only observed for half the recommended time before being declared safe, and there was no adequate standard operating procedure for sterilization or transfer. The CDC says that employees who were involved in the incident or should have stopped it will be disciplined, and it will establish both an advisory board and a central point of accountability for lab safety. It's started a fuller investigation into the avian flu incident and established review groups to examine the safety procedures. The CDC will also examine whether it should make larger changes in how it treats samples. In statements published by The New York Times, Frieden says that dangerous materials around the world should to be restricted to fewer labs where fewer people have access to them.

And if you needed more bad news, he also confirmed that two of the the forgotten vials of smallpox found in an FDA storage room last week contained live and potentially infectious virus samples.