WASHINGTON, July 8 (Xinhua) -- The U.S. Centers for Disease Control and Prevention (CDC) said Tuesday they have found vials containing smallpox that appear to date from the 1950s in a government lab's storage room, a startling discovery because an international agreement says smallpox is only permitted in two labs in the world: a different lab in the U.S., and another in Russia.
The vials labeled "variola," commonly known as smallpox, was discovered on July 1 in an unused portion of the storage room in a lab that belonged to the U.S. Food and Drug Administration (FDA), the CDC said. The FDA lab was located on the campus of the National Institutes of Health (NIH) in Bethesda and among those transferred from NIH to FDA in 1972, along with the responsibility for regulating biologic products.
Employees discovered the vials while preparing for the laboratory's move to the FDA's main campus, the CDC said.
"Upon discovery, the vials were immediately secured in a CDC- registered select agent containment laboratory in Bethesda," the U. S. agency said in a statement.
"There is no evidence that any of the vials labeled variola has been breached, and onsite biosafety personnel have not identified any infectious exposure risk to lab workers or the public," it said.
According to the CDC, the vials were transported late Monday night to the agency's facility in Atlanta, Georgia, where testing confirmed the presence of smallpox virus DNA.
Additional testing is still under way to determine if the smallpox is viable, after which the samples will be destroyed, it said.
The CDC's Division of Select Agents and Toxins (DSAT), in collaboration with the Federal Bureau of Investigation, is investigating the history of how these samples were originally prepared and subsequently stored in the FDA lab.
Smallpox, an acute contagious disease caused by the variola virus, was one of the world's most devastating diseases known to humanity. It was declared eradicated in 1980 following a global immunization campaign led by the World Health Organization (WHO).
Under an international agreement, there are currently two official WHO-designated places for smallpox: the CDC in Atlanta and the State Research Center of Virology and Biotechnology ( VECTOR) in Novosibirsk, Russia.
The CDC said that it has notified the WHO about the discovery and invited the WHO to participate in the relevant investigation.
"If viable smallpox is present, WHO will be invited to witness the destruction of these smallpox materials, as has been the precedent for other cases where smallpox samples have been found outside of the two official repositories," it added.