In a follow-up to the Thursday story of Centers for Disease Control and Prevention (CDC) staffers potentially exposed to the dangerous bacterium, Bacillus anthracis, the federal health agency will cede the investigation to the U.S. Department of Agriculture “to avoid potential conflicts of interest.”


When originally reported in a CDC press release Thursday, officials noted approximately 75 staff may have been exposed to the lethal organism; however, that number increased on Friday when CDC spokesman Benjamin Haynes said in an email that the number has increased to 84 potential exposures.

Haynes went on to say it was “simply a breach of protocol”. “The protocol calls for inactive anthrax to be slided and observed after 48 hours to see if spores develop. This particular sample was checked and sent to lower-level labs after 24 hours.”

The lower-security clearance labs are not equipped to handle the live anthrax virus. And employees, believing the samples to be harmless, were not wearing the proper protective gear for handling the active virus, the CDC said. The two staff members most closely involved with the incident received immediate medical attention on 13 June, when the exposure was discovered, Haynes said. The CDC experiments used the more lethal Ames strain instead of the Sterne strain, which can infect but can’t keep reproducing, CIDRAP reported Friday.

As of Friday, 52 staffers were given prophylactic antibiotics (ciprofloxacin or doxycycline), while another 27 received the anthrax vaccination.

The incident is drawing scrutiny from Congress about whether the CDC has the appropriate safety procedures in place to protect federal employees from contamination. This is not the first time a breach occurred at a high level biosafety laboratory, including the CDC. Here are a few examples:

In 2008, a backup generator at the CDC failed after a power outage leaving high containment facilities without power for negative air pressure, freezers, etc.  CDC ignored warnings from engineers.

Then there was the situation at Texas A&M University (TAMU) in College Station in 2006. By human error and faulty equipment, university researchers infected themselves with brucella and Q fever (C. burnetii). The infections were not promptly diagnosed. Senior officials at this major research university then decided to ignore the law requiring the incidents to be reported, ultimately resulting in a research shutdown and large fine. For more infectious disease news and informationvisit and “like” the Infectious Disease News Facebook page

Then there was the 1978 incident at Plum Island Animal Disease Center when the very dangerous animal disease, Foot-and-mouth disease (FMD) was found in cattle outside the facility in holding pens. Author Michael Carroll documents many more in his book, Lab 257.  Did Lyme disease originate out of Plum Island?