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Stray vials of the deadly smallpox virus from the 1950s have been discovered at a federal lab near Washington, US health officials say, marking the second major lapse in a month in the way the United States handles deadly pathogens.
The U.S. Centers for Disease Control and Prevention said that workers discovered the vials in a cardboard box on July 1 while clearing out an old lab on the National Institutes of Health campus in Bethesda, Maryland.
The six glass vials contained freeze-dried smallpox virus and were sealed with melted glass. The vials appeared intact and there is no evidence that lab workers or the general public are at risk, said CDC spokesman Tom Skinner.
The mishandling of smallpox follows the CDC's recent mishap in which the agency believed it may have transferred live anthrax samples to a CDC lab that was not equipped to handle them, potentially exposing dozens of employees to the pathogen.
The CDC is testing the vials to see if the smallpox is viable and could make someone sick, said Skinner. After those tests, the samples will be destroyed, Skinner said.
Smallpox was eradicated worldwide in 1977, but samples of the pathogen are kept in two repositories for research purposes: the CDC's facility in Atlanta and the State Research Centre of Virology and Biotechnology in Novosibirsk, Russia. The two repositories are monitored by the World Health Organization.
The CDC said it has notified WHO about the discovery. If the specimens turn out to be viable, the CDC said it will invite the WHO to witness the destruction of the smallpox samples.
Although there have been concerns smallpox could be used in bioterrorism, the CDC says the chances of that occurring are very low. Currently, the government has a stockpile containing enough vaccine for every U.S. citizen.