The US Army lab that sent samples of live anthrax to sites around the globe followed proper procedures, but those procedures weren't sufficient to ensure dead samples, the New York Times reports.
"Obviously, when over half of anthrax batches presumed to be inactivated instead prove to contain live anthrax spores, we have a major problem, and the numbers confirm this judgment," Deputy Defense Secretary Bob Work says in a statement.
Back in May, federal agencies said they were investigating shipments of live anthrax from the Dugway Proving Ground, an Army facility, to other locations in the US, Australia, Canada, and South Korea.
An initial Pentagon review has now found that the procedures in place at the facility weren't sufficient to kill anthrax, the Times says. Only about 5 percent of irradiated anthrax samples were checked to be sure it was inactivated, the Times notes, adding that such a low testing rate enabled live ones to slip through.
"This represents an institutional problem," the Pentagon review says, "and does not necessarily reflect on any one individual."
The Times notes that this is the latest in a rash of incidents involving the improper handling of infectious agents by federal agencies. Last summer, unsecured smallpox was uncovered at the National Institutes of Health, while anthrax and influenza samples were mishandled at the Centers for Disease Control and Prevention.