Senior Pentagon officials expect the numbers to increase as additional testing of anthrax lots continues and stress that there is no risk to the general public because the concentrations of anthrax involved are too low to affect an average person.
“We expect this number may rise because the scope of the investigation is going on and we will update these numbers daily until all of the investigation is complete,” Deputy Defense Secretary Robert Work said at a Pentagon briefing.
Work said 400 lots of irradiated anthrax stored at four U.S. military facilities are being tested to see whether they contain any live anthrax. Four of those lots, from the Army’s Dugway Proving Ground in Utah, have been found to contain a mix of live and inactivated anthrax.
Investigators have pieced together that samples from those lots have been sent to 51 laboratories in 17 states, the District of Columbia, South Korea, Australia and Canada.
The states are California, Delaware, Maryland, Massachusetts, New Jersey, New York, Tennessee, Texas, Utah, Virginia, Washington, Wisconsin, Arizona, Florida, Illinois, Ohio and North Carolina.
Testing by the Centers for Disease Control and Prevention testing has found live anthrax in 10 samples that had been sent to laboratories. While the tests can detect live anthrax within a 24- to 48-hour span, conclusively proving that a sample contains fully inactivated spores cannot be determined for 10 days.
“There are no suspected or confirmed cases of anthrax infection among any workers in any of the labs that have received these samples for the last 10 years,” Work stressed.
“We know of no risk to the general public. To provide context, the concentrations in these samples are too low to affect the average healthy individual.”
Though at a low risk of infection from potential exposure, the number of lab personnel now on protective antibiotics has risen to 31. The number had been at 25 last week.
Work explained that for the past decade the Pentagon has shipped samples of inactivated anthrax to commercial and academic laboratories in the United States and abroad to help develop better field detection technologies.
Since 2005, live anthrax strains have been irradiated at the military laboratories to render them inactive and tested for up to 10 days after to ensure they contained no live anthrax. Samples from these supposedly inactivated lots have been sent regularly to the 300 labs in the United States authorized to work with anthrax.
No questions had been raised about the procedures and testing until May 22 when a lab in Maryland notified the CDC that it had found live anthrax in a sample it had received from the Dugway facility.
Today’s briefing included an in-depth demonstration of the shipping and packing procedures for samples of live and dead anthrax intending to ease concerns that anthrax samples had routinely been shipped by FedEx.
Anthrax samples are shipped in a vial containing spores suspended in a milliliter of frozen liquid. The vial is placed in a plastic sealed sandwich bag that is wrapped in absorptive material. This goes into a hard plastic container that is placed into a cardboard box containing dry ice to keep the liquid in the vial frozen.
The only difference between the packaging for live and inactive anthrax is that a label marked “infections substance” is placed on boxes containing live anthrax, said Commander Franca Jones, the director of Medical Programs for the DOD’s chemical and biological programs.
“When we talk about risk to the public and what’s happening with this box, and workers who might have handled this box in the transportation chain, we believe that the risk is zero for the general public as well as the people who’ve handled this box,” Jones said. “One milliliter of liquid is not going to come out of this box. ”
Jones said laboratory workers have an “extremely low risk” for exposure when the samples are initially packed or opened.