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.
Independent experts
say it appears to be the largest incident 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.
"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," a statement from the agency says.
The
problem was discovered last Friday, and some of the anthrax may have
become airborne in two labs the previous week, the statement says.
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."
"It’s really
unfortunate that this happened. It’s unacceptable and we’re going to do
everything we can to understand why it happened and what we need to do
differently to make sure it doesn’t happen again," said CDC spokesman
Tom Skinner.
He said the incident was revealed on Thursday, nearly
a week after it was discovered, because the first priority was
investigating the extent of the problem and notifying workers.
"When we learned what had happened we moved as swiftly as possible to contact anyone who was
possibly exposed," he said.
Skinner said he did not know how many employees were taking antibiotics or how they were exposed.
Anthrax
infections can occur through skin contact but "if you inhale it and you
get it in the lungs, that’s a lot more dangerous," said Paul Roepe, an
infectious disease specialist at Georgetown University Medical Center.
The ability of antibiotics to prevent infection depends on how quickly
they are started, he said.
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, and he urged the CDC to fully disclose the
results of its investigation.
"It’s important to learn what
happened there so we can ensure it doesn’t happen again," he said. Labs
"work on anthrax all the time," and the CDC’s statement seems to suggest
human error, "not a system failure."
"They’re taking all the necessary steps" for potentially exposed workers, he added.
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Online:
CDC anthrax: http://www.cdc.gov/anthrax/