About 75 workers at the Centers for Disease Control and Prevention may have been accidentally exposed to dangerous anthrax bacteria this month because of a safety problem at some of its labs in Atlanta, the federal agency revealed Thursday.
An independent expert said it appears to be the largest case involving anthrax, a potential bioterrorism agent, in a U.S. lab in at least a decade. CDC officials say the risk of infection seems very low, but the employees were being monitored or given antibiotics as a precaution.
The safety lapse occurred when a high level biosecurity lab was preparing anthrax samples.
The samples were to be used at lower security labs researching new ways to detect the germs in environmental samples. The higher security lab used a procedure that did not completely inactivate the bacteria.
Workers in three labs who later came into contact with these potentially infectious samples were not wearing adequate protective gear because they believed the samples had been inactivated.
Procedures in two of the labs may have spread anthrax spores in the air.
Live bacteria were discovered last Friday on materials gathered for disposal. Labs and halls have been tested and decontaminated and will reopen when safe to operate, the CDC statement says.
Because proper procedures were not followed, the agency said workers will be disciplined as necessary.
Anthrax created fear in 2001, when five people died and 17 others were sickened from letters containing anthrax spores sent through the mail. The FBI blames the attacks on a lone government scientist, Bruce Ivins, who committed suicide.
Scott J. Becker, executive director of the Association of Public Health Laboratories, said this appears to be the largest potential anthrax exposure in a lab since then.