Many scientists argue any samples of smallpox pose a threat and they should be wiped off the planet altogether. (CDC)
Atlanta A government scientist cleaning out an old storage room at a research center near Washington made a startling discovery last week decades-old vials of smallpox packed away and forgotten in a cardboard box.
The six glass vials were intact and sealed, and scientists have yet to establish whether the virus is dead or alive, the Centers for Disease Control and Prevention said Tuesday.
No lab workers or members of the public were exposed to the infectious and potentially deadly virus, the CDC said.
Still, the find was disturbing because for decades after smallpox was declared eradicated in 1980, world health authorities said the only known samples left were safely stored in super-secure laboratories in Atlanta and in Russia. The most common type of smallpox is serious, contagious and frequently fatal, with about 30 percent of cases resulting in death, according to the CDC.
Officials said this is the first time in the U.S. that unaccounted-for smallpox has been discovered. At least one leading scientist raised the possibility that there are more such vials out there around the world.
The CDC and the FBI are investigating.
The last U.S. case of smallpox was in 1949, and the last naturally occurring case anywhere in the world was in Somalia in 1977, according to the CDC. Since then, according to the World Health Organization, the only known cases stemmed from a 1978 lab accident in England.
The freeze-dried smallpox samples were found in a building at the National Institutes of Health in Bethesda, Maryland, that has been used by the Food and Drug Administration since 1972, according to the CDC.
The scientist was cleaning out a cold room between two laboratories on July 1 when he made the discovery, FDA officials said.
Officials said labeling indicated the smallpox had been put in the vials in the 1950s. But they said its not clear how long the vials had been in the building, which did not open until the 1960s.
Los Angeles Times contributed.