While it is difficult to turn anthrax into a weapon of mass destruction, it is quite easy to grow the bacteria in a lab and distribute small quantities piecemeal, even through the mail, experts said Saturday.
"Growing this organism is no problem," said Norman Cheville, dean of the Iowa State University's School of Veterinary Medicine. "It grows readily. It grows overnight."
Until last week, the threat of anthrax had been couched largely in terms of its use as a weapon of mass destruction and how difficult that would be. But the death of a man in Florida and the infection of an NBC News employee in New York have shed light on the ease of using anthrax for individual criminal acts.
New York officials confirmed Saturday that an envelope opened by an NBC staff member tested positive for anthrax. Another letter sent to a Microsoft office in Reno, Nev., also tested positive, Nevada officials said.
Postal Service action sought
Bioterrorism experts say the use of the U.S. Postal Service to transmit lethal bacteria is significant and should trigger changes in how mail is handled.
"After hundreds of threats and hoaxes in the last few years, somebody has finally been able to do it," said David Siegrist, director of studies for Countering Biological Terrorism at the Potomac Institute for Policy Studies in Virginia. "That has to guide our judgment going forward on how we treat some of these threats."
In the short term, Siegrist said, company mailroom employees should use rubber gloves and be vigilant for suspicious packages with no return addresses, block lettering and excessive tape. Going forward, though, he said, the post office must develop and use new technologies that protect against the spread of biological agents.
Postal officials say there's no way to inspect personally the hundreds of millions of letters and packages delivered every day. They have urged the public to be cautious and to report suspicious activity.
Small quantities; big problems
A few milligrams of anthrax, which would not be visible to the naked eye, contain millions of anthrax spores, enough to infect thousands of people if dispersed properly, experts said. More than likely, most people would only be able to produce a small fraction of that.
"This is what you can do with any germ," said Philip Hanna, a professor of microbiology and immunology at the University of Michigan. "Anthrax is just new to the United States' perspective. What's scarier is the intent, not the technologies.
"Fertilizer isn't particularly scary, but if you put it into a van with gasoline and drive it to a federal building, you can blow it up." That's what happened in 1995 at the Alfred P. Murrah federal building in Oklahoma City.
Fortunately, Hanna said, the human body is somewhat resilient to anthrax, and it takes thousands of spores to cause infection. "Anthrax is a very inefficient sort of murder weapon," he said. "If you send out thousands of anthrax letters, even if they're all opened, very few people are going to contract the disease. For once with anthrax, nature cuts us a break."
For instance, in Florida, only one person died of inhalation anthrax; at least seven others tested positive for exposure but did not become ill.
Until the mid-1990s, the government kept few tabs on who shared and sold samples of anthrax and other dangerous bacteria. In the mid-1980s, before the Persian Gulf War, the not-for-profit biological supply company American Type Culture Collection sold three strains of anthrax to Iraq, which reportedly used the bacteria to create biological weapons.
Then, in 1995, a laboratory worker at Ohio State University obtained three vials of bubonic plague from American Type by falsifying university letterhead.
The man, Larry Wayne Harris, pleaded guilty to one count of wire fraud. Harris, a member of the white supremacist group Aryan Nations, also claimed that he cultivated anthrax by taking samples from a 20-year-old burial site for cattle that had died of the disease.
After realizing lax lab controls, Congress passed a 1996 law that severely limits the interstate shipment of anthrax and other pathogenic strains, such as plague.
Researchers wishing to obtain anthrax today must first receive a license from the Centers from Disease Control and Prevention. In addition, shippers must inform the government when they send an anthrax sample, and researchers must then acknowledge receipt.
Labs are not the only place to obtain anthrax, though. The bacterium can be obtained from contaminated animals or from soil near where the animals are buried, experts said.
In addition, labs and some foreign governments have samples of anthrax.
Of the 472 cell culture collections registered with the World Federation of Culture Collections, 46 contain virulent strains of Bacillus anthracis. Those strains can be purchased by scientists, and the rules vary depending on the country of origin.