Last Updated

14 Jun 2003

Source: Baltimore Sun, December 21, 2001.

Anthrax genetic trail may be a dead end

Ames strain was shared widely, researcher says; ABC suspect story denied

By Scott Shane, Sun Staff

The scientist who 20 years ago obtained for the Army the virulent Ames strain of anthrax used in the recent mail attacks said yesterday that he doubts it is possible to identify all of the laboratories that shared the strain.

Gregory B. Knudson, who worked at the U.S. Army Medical Research Institute of Infectious Diseases from 1978 to 1988, said he received the Ames strain in the early 1980s from a U.S. Department of Agriculture veterinary laboratory in Ames, Iowa. Ames was one of many strains he collected at the time from around the world to test the efficacy of vaccines, he said.

But Knudson said his experience at Fort Detrick in Frederick demonstrated the informality that governed the exchange of anthrax at a time when few researchers thought of bacteria as a potential terrorist weapon.

"In those days, people would share strains," said Knudson, who now works at another government lab. "There wasn't necessarily any documentation."

Also yesterday, officials said there was no basis for an ABC News report Wednesday night that said the FBI's anthrax investigation was focusing on a scientist fired by Battelle Memorial Institute, a defense and Central Intelligence Agency contractor based in Ohio. One person familiar with Battelle's government contract work said ABC's assertion that Battelle has used dry, powder anthrax is also wrong.

Knudson's point about past sharing of anthrax samples is a critical one in the 10-week-old anthrax investigation because the FBI hopes that sophisticated genetic testing will help identify the source of the mailed anthrax.

Researchers at Northern Arizona University have found that the anthrax in the letter mailed to Senate Majority Leader Tom Daschle of South Dakota is an exact genetic match for the Ames "reference" strain - the strain received by Knudson 20 years ago.

News reports have suggested that the number of laboratories that might have been the source of the anthrax used in the attacks is slowly being narrowed, possibly to fewer than a dozen. But if the Ames strain was widely and informally shared among researchers, as Knudson and other scientists say, there may be no way today to identify with certainty all the possible sources.

If a researcher sent a sample of the Ames strain to another scientist in the 1980s without recording the transfer, a sample could have sat forgotten for years in a freezer at a university lab in the United States or even overseas, Knudson said. A terrorist could have used such a sample to produce the anthrax used in the letters, which have killed five people and sickened 13 others.

To further confuse matters, he said, there may be other sources of anthrax that are not labeled "Ames" but are genetically identical. The cow that died of anthrax near Ames in 1980 or 1981 and from whom the Ames reference strain was cultured might have been infected by anthrax spores that had lain dormant in the ground for years after previous outbreaks. Samples taken from the previous outbreaks might have a different strain name but still match Ames exactly.

For example, in 1983, about the same time as he received the Ames sample from the USDA's National Veterinary Services Laboratories, he got five other strains of anthrax from a different facility also located in Ames, Iowa - Iowa State University.

Those five strains were identified as "1928," an Iowa sample named for the year it was labeled; "NEBR," for Nebraska; "Buffalo," for a strain isolated from a dead buffalo in Ohio; "Albia," for a strain found in Albia, Iowa; and "3515," a strain received from the USDA 20 years earlier. Their documentation was sketchy. The technology of the time did not allow for genetic fingerprinting to determine whether they matched one another or the Ames strain, Knudson said.

Despite what would appear to be his unique knowledge of the early history of the Ames strain, Knudson said he has never been contacted by the FBI.

A more promising clue in hunting the perpetrator than the genetic analysis of the powder in the letters may be its physical state: extraordinarily fine particles of the size necessary to be inhaled into the lungs.

Most experts on biological weapons say the production of the fine, concentrated anthrax powder in the Daschle letter is a demanding technical task that points to a government weapons program. Other experts, however, contend that it is not beyond the capabilities of a determined terrorist working in a well-equipped home lab.

In this country, only the Army's Dugway Proving Ground in Utah is known to have made finely milled, weapons-grade anthrax in recent years. Small quantities of the powder, including some of the Ames strain, are used to test detection equipment and decontamination techniques, according to people familiar with the work.

Battelle, the Ohio defense and CIA contractor, has used wet anthrax aerosol to test vaccines in animals, as has Fort Detrick. But officials familiar with the work at both places insist that no dry anthrax has been used.

The CIA said yesterday that some of its contractors have conducted anthrax research, but never with "dried or powdered" bacteria. The agency does not have anthrax at its own facilities, the statement said.

If the Ames strain was shared informally, as Knudson says, it may have been produced as a fine, dry powder by a secret weapons program of another country. While the FBI is focusing on the possibility of a domestic source for the mailed anthrax, investigators have not ruled out a foreign source, officials say.