Up to 75 scientists who work at a US Centers for Disease Control and Prevention biosecurity lab in Atlanta may have been exposed to anthrax, because researchers there did not follow procedures for inactivating the deadly and highly contagious bacteria.
None of the scientists at the federal lab have symptoms, but some are being treated with antibiotics "out of an abundance of caution," a CDC spokesperson told Reuters.
From the New York Times:
The lapse occurred sometime from June 6 to June 13. Workers who were not wearing appropriate protective gear moved samples of the highly infectious bacteria that they believed had been deactivated. The agency said in a statement that procedures used in two laboratories in Atlanta, where the C.D.C. is based, may have "aerosolized the spores," essentially pushing active parts of the bacteria into the air. The exposure was discovered June 13, when the bacterial plates were to be disposed of, and live B. anthrasis colonies, or anthrax bacteria, were found on them, the agency said. The plates had tested negative for the bacteria at the time they were distributed to the labs, the agency said.
Reuters has a related early report with additional details.