Up to 75 scientists working for the US government’s Centers for Disease Control and Prevention (CDC) in Atlanta may have been exposed to potentially deadly live anthrax, the state health agency said on Thursday.
The potential exposure occurred after researchers working in a high-level bio-security laboratory at the agency’s Atlanta campus failed to inactivate the bacteria properly.
Scientists at the Bioterror Rapid Response units had been preparing an especially dangerous strain of the bacteria for use in tests at two lower-security CDC labs, said Dr Paul Meechan, director of the CDC’s environmental health and safety compliance office, in comments to Reuters.
Those teams were experimenting with methods to more quickly identify anthrax in substances and powders.
Meechan said the team had used a new process to purify the anthrax samples. To check their work, they took a sample of what they thought was dead bacteria and put it on a nutrient-rich lab dish called an agar plate to see if the bacteria would grow.
“They waited 24 hours. They took a look at the plate and they didn’t see any new growth,” Meechan said. “At that point they assumed the material was safe.”
Researchers took the slides to the two lower-security CDC labs that were trying to develop the new tests. Their experiments did not work and a week later, one of the labs asked for additional inactivated samples.
Researchers in the bioterror lab then discovered that they had left the agar plates in an incubator for an additional week, Meechan said. As they were about to dispose of them, they noticed growth on one of the plates.
“The growth turned out to be anthrax, he said.
A CDC spokesman said the risk of infection was "very low".
"Workers, believing the samples were inactivated, were not wearing adequate personal protective equipment while handling the material," spokesman Tom Skinner said in a statement.
“Out of an abundance of caution, CDC is taking aggressive steps to protect the health of all involved, including protective courses of antibiotics for potentially exposed staff," Skinner said. "Based on most of the potential exposure scenarios, the risk of infection is very low."
"Based on the investigation to date, CDC believes that other CDC staff, family members, and the general public are not at risk of exposure and do not need to take any protective action," the center said.
Anthrax is a disease caused by a germ that lives in soil, and gained notoriety after a spate of US mail attacks in 2001 killed five people.
(FRANCE 24 with REUTERS and AFP)
Date created : 2014-06-19