About 75 scientists may have been exposed to live anthrax bacteria in U.S. government laboratories in Atlanta and are being treated to prevent the infection, the Centers for Disease Control and Prevention said.
The scientists at the CDC in Atlanta were working in lower-security labs not equipped to handle live anthrax and received samples of the bacteria from a higher-security lab, the agency said. The unintentional exposure was discovered June 13 when live bacteria was found on the original bacteria plates during disposal, Tom Skinner, a spokesman for the CDC, said in a statement.
"Based on most of the potential exposure scenarios, the risk of infection is very low," Skinner said.
Anthrax is a deadly infection caused by the spore-forming bacillus anthracis, more often found in cows and sheep than humans. CDC is giving potentially exposed workers protective antibiotics and doesn't believe other CDC staff, family members or the general public are at risk, Skinner said.
Anthrax was highlighted as a potential weapon of mass destruction in 2001 when mail laced with the spores was sent to media organizations and the offices of some U.S. senators. Five people died after the bioterrorism incident.
A CDC investigation found lab staff sent samples that were supposed to be inactivated to the lower-security labs. The proper procedures weren't followed and live bacteria was transfered, the agency said.
The samples were used for experimentation in three labs on the center's main Roybal campus that were studying new means of detecting dangerous pathogens, Skinner said.
Disciplinary action may be taken since protocols weren't followed, Skinner said.
"It shouldn't happen, but it is hard to keep accidents from happening," said John Keene, president of Global Biohazard Technologies Inc. and a past president of the American Biological Safety Association. "The researchers are always at risk."
Still, Keene said accidental exposures like this are "very, very rare"
While the researchers would be at risk of getting infected only if they inhaled the spores, treatment with antibiotics is extremely effective, he said. Anthrax isn't transmitted from person to person.
"Getting it out of the lab isn't necessarily going to cause a significant danger to people working there," Keene said. "Unless someone was doing something that could create an aerosol to breath it in, the probability of getting infected with it is slim to none."
Two of the labs were closed after it was determined they may have aerosolized the spores sometime from June 6 to June 13. The labs have been decontaminated and will re-open when safe to operate, Skinner said.
Steve Brozak, president of WBB Securities LLC who has researched and invested in infectious disease companies, said he would be more worried about whether other, more lethal pathogens were also improperly moved out of a high security area.
"If these haven't been killed, is it possible anything else made it through?" he said. "This will more than likely have people looking over their shoulder to make sure they are following the proper procedures."
Anthrax can also spread to farm workers or others who are exposed to diseased animals. The bacteria can infect the lungs or digestive tract, though most infections start when the bacterial spore penetrates the skin. It can also be contracted by eating diseased meat, according to the CDC.
People exposed to it are typically treated with antibiotics, including Bayer AG's Cipro, though the medicine can't disable the toxins produced by the bacteria.
GlaxoSmithKline Plc's raxibacumab was approved in 2012 to treat anthrax, in combination with antibiotics, for people with an inhaled form of the infection. The medicine can also be given as a preventive option to those who have been exposed to bacillus anthracis.
Emergent Biosolutions Inc. produces BioThrax, an anthrax vaccine held as part of the Strategic National Stockpile. It plans to file for U.S. approval by the end of the year to use the vaccine to prevent infection after people have been exposed to the bacteria. It is also developing a second vaccine called PreviThrax.