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CDC Director Thomas Frieden

CDC Director Thomas Frieden

Center for Disease Control/Wikimedia Commons

Lab incidents lead to safety crackdown at CDC

The U.S. Centers for Disease Control and Prevention (CDC) has closed two labs and halted some biological shipments in the wake of several recent incidents in which highly pathogenic microbes were mishandled by federal laboratories. The cases include an accidental shipment of live anthrax; the discovery of forgotten, live smallpox samples; and a newly revealed incident in which a dangerous influenza strain was accidentally shipped from CDC to another lab.

The two cases involving CDC mistakes reveal “totally unacceptable behavior” by staff, said CDC chief Thomas Frieden at a press conference today at CDC headquarters in Atlanta. He announced several actions that CDC is taking to step up safety and security, including a moratorium on shipping highly risky pathogens. “I’m disappointed by what happened and frankly I’m angry about it,” he added.

Frieden also revealed that two of six vials of smallpox discovered last week in a cold storage room in a Food and Drug Administration lab at the National Institutes of Health (NIH) in Bethesda, Maryland, have tested positive for live virus when grown in culture. Some smallpox experts had predicted that the 1950s-era samples would no longer be viable. Four samples have yet to be tested; all will then be destroyed, Frieden said.

CDC’s actions follow an incident last month in which up to 75 CDC workers were potentially exposed to anthrax when samples thought to be dead proved to be live. A CDC internal report released today describes how scientists failed to follow proper procedures to ensure samples were inactivated before they left the lab. The investigation also found “multiple other problems” with operating procedures in the anthrax lab, Frieden said. 

The report also describes a second incident that occurred 6 weeks ago but came to Frieden’s attention “less than 48 hours ago,” he said. In mid-March, a CDC influenza laboratory sent a shipment of a low-pathogenic strain of H9N2 avian influenza to a U.S. Department of Agriculture (USDA) poultry lab. Tests there revealed it was contaminated with the highly virulent H5N1 avian influenza strain, which can infect and sicken humans. Although USDA notified the CDC lab on 23 May, senior leadership at CDC was not informed until 7 July, Frieden said. His concerns are that the lab’s “superb laboratory” could make such a mistake and that higher-ups weren’t notified sooner. “That kind of delay is very troubling,” he said.

Meanwhile, FDA and NIH are “scouring” their labs to make sure they have no more forgotten smallpox samples, Frieden said.

In response to the incidents, which so far have resulted in no known exposures to workers or the public, CDC has temporarily closed both the anthrax lab and the influenza lab that shipped the H5N1 samples. The agency is also the halting all shipments of pathogens from its highest security laboratories (known as biosafety level 3 and biosafety level 4) until safety procedures have been improved.

Frieden has appointed Michael Bell, a CDC deputy director, to oversee all lab safety at CDC and asked him to report on ways to improve procedures in consultation with an internal working group and outside advisers. In addition, personnel who violated protocols or reporting rules will be disciplined, Frieden said.

The lapses at the world-renowned infectious disease research agency are sure to raise questions about safety at other labs studying highly pathogenic agents, including university labs that are modifying influenza strains to make them more virulent. Frieden said that “whatever you think about” such so-called gain-of-function studies, “I think it’s clearly the case that these incidents indicate that we need to really ensure that whatever work is done needs to be done safely and securely.”

*Update, 13 July, 10:26 a.m.: The item was updated to clarify that H5N1 is an avian virus and to correct a typographic error.