Investigators believed a high-security bioterrorism laboratory may not have sent out live anthrax samples by mistake, despite initial fears, Reuters reports.
Organisms removed from the laboratory earlier this month may have first been soaked in acid for 24 hours, far longer than the 10-minute exposure of a sample that showed signs of life in the secured facility days later, the news agency reported on Friday. The discovery of the live agent prompted concern that samples sent out of the laboratory may have included live bacteria, potentially exposing dozens of personnel in lower-security areas of the Centers for Disease Control and Prevention in Atlanta.
"We want to know whether or not in the 24 hours when they were waiting for that plate to grow, they were actually killing more of the anthrax, and possibly all of it," said Paul Meechan, head of the CDC Health and Safety and Environment Office.
In a new investigation, scientists placed quantities of anthrax in the acid for varying periods of up to 24 hours.
"The idea is to see how much time it takes to kill everything in that solution," Meechan said by telephone.
Agency spokesman Tom Skinner said the study's conclusions are anticipated in the near future.
Meanwhile, another internal probe is seeking to determine why anthrax removed from the bioterrorism laboratory was held in acid for no longer than 24 hours, despite a requirement that it receive the neutralization treatment for at least twice that long.
"The fact that [anthrax exposure] was even a concern or that it might have happened is unacceptable," CDC Director Thomas Frieden told Reuters. "Employees should never have to be concerned about their safety from preventable exposures."