January 30, 2002
Geographic Gaffe Misguides Anthrax Inquiry
By WILLIAM J. BROAD
he postmarks on the deadly letters laced with anthrax made clear from the start that they came from Trenton. But tracing the origin of the strain of anthrax that killed five people last fall has been a far murkier venture. And it now turns out that scientists and investigators have been on the wrong trail all along.
Federal investigators have found in recent weeks that the so-called Ames strain was first identified not in Ames, Iowa, its reputed home, but a thousand miles south, in Texas. The strain of the bacteria was found on a dead cow near the Mexican border in 1981, and the geographic gaffe was the result of a clerical error by a scientific researcher.
It was of little consequence until last October, when investigators determined that the anthrax in the nation's first major bioterrorism attack matched the "Ames strain." Then the clerical error wound up taking the investigation on several wrong turns.
Investigators spent considerable effort trying to find the genesis of the strain in Iowa, issuing a subpoena to Iowa State University, which was known to have a sizable library of anthrax samples. Investigators persisted, even though Iowa state officials said they could find no evidence of the Ames strain.
The discovery of the true origin of Ames "looks like it gets Iowa off the hook," a senior law enforcement official said yesterday.
The criminal investigation also focused on the possibility that the anthrax used in the attacks was left over from the nation's bioweapons program, which was shut down in 1969. A scientific paper published in 2000 said Ames anthrax was a strain used in the program. But now, with the discovery that Ames emerged from Texas in 1981, that part of the investigation has also lost steam.
The discovery of the error also sheds a disturbing light on the prevalence of the virulent Ames strain. Until recently, Ames was seen as a germ that had an uncertain origin in nature and was locked away in several laboratories around the country. But now scientists and veterinary doctors say they believe that Ames is common throughout Texas.
This raises a possible public health concern and increases the possibility that last fall's bioterrorist could have simply dug anthrax out of the dirt in Texas.
"We isolate a lot of anthrax here," said Lelve G. Gayle, director of the Texas Veterinary Medical Diagnostic Laboratory in College Station. He said the Ames strain now appeared to be widely scattered in natural settings. It was found in a dead goat on a Texas ranch in 1997.
The new history of Ames, some of which was reported yesterday in The Washington Post, is being investigated by the F.B.I. along with the National Intelligence Council, which does federal threat assessments, and the Central Intelligence Agency.
"This one is the true Ames," a C.I.A. analyst said of the Texas germ. He added that the anthrax that panicked the nation last fall "all came from Texas."
That history starts in late 1980 when Gregory B. Knudson, a biologist working at the Army's biodefense laboratory at Fort Detrick, Md., was searching for new anthrax strains to use in tests of the military's vaccine. In December 1980, he wrote Texas A&M veterinary officials, according to documents obtained from Dr. Knudson.
"Unfortunately, I have discarded all my pathogenic cultures," Howard W. Whitford replied in January 1981. But he said warmer weather would probably bring new outbreaks.
Indeed, in May 1981, the disease struck a herd of 900 cows at a ranch near the Mexican border.
"This heifer in excellent flesh was found in the morning unable to rise," Michael L. Vickers, a veterinarian in Falfurrias, Tex., wrote in his case report. "By noon she was dead."
In an interview, Dr. Vickers said: "This is a very lethal strain of anthrax we have down here. It's nothing to play with. I've seen as many as 30 head of cattle die a day until they're inoculated."
Dr. Vickers sent anthrax specimens to the Texas Veterinary Medical Diagnostics Laboratory, an arm of Texas A&M. The Texas laboratory, remembering Dr. Knudson's request, sent a sample along to Fort Detrick.
That is where the mix-up began. The Texas lab sent the iced specimens to Fort Detrick with a prepaid mailing label that Dr. Knudson has carefully preserved among his papers. Its return address is not Texas A&M at College Station but rather the National Veterinary Services Laboratories, in Ames, Iowa, an arm of the federal Agriculture Department that does diagnostic tests for state and foreign veterinary labs.
The Texas laboratory frequently sent shipments to Ames using prelabeled boxes with prepaid postage. In this case, it put on an additional label to redirect the box to Fort Detrick, with the national laboratory in Ames as the return address.
The return address blur soon became a scientific muddle.
At Fort Detrick, Dr. Knudson had gathered 27 anthrax strains. "I called this `Ames' since it came from Ames," he recalled in an interview.
In May 1986, his vaccine study and the Ames strain made their public debut. Dr. Knudson and Stephen F. Little of Fort Detrick reported in a science paper that the highly lethal strain, which killed six out of six vaccinated guinea pigs, had come from an Iowa cow.
Biologists recycled the mistake. The issue grew muddier in May 2000 when a scientific paper claimed incorrectly that Ames had been used in the American germ weapons program that was shut down in 1969.
The academic confusion became a public drama last fall. After federal experts identified the strain in the bioattacks as Ames, reporters and investigators descended on the city in Iowa.
Gov. Tom Vilsack of Iowa sent armed troopers and Iowa National Guard soldiers to safeguard Iowa State University's cache of anthrax microbes, which were kept in more than 100 vials. Some news reports said the attack germs had been stolen.
Officials in the College of Veterinary Medicine tore through old files and read cryptic labels on vials but could find no documentation that any of their germs were the Ames strain. They could find nothing to support Dr. Knudson's 1986 paper that said Ames had originated in an Iowa cow.
"We figured it had to have come through here, but we couldn't prove it," recalled James A. Roth, an assistant dean.
In early October, the college destroyed its anthrax collection after deciding that the germs were not worth the trouble of the new high security. In an Oct. 12 statement, the college pointed a finger at its neighbor, the National Veterinary Services Laboratories, saying it "appears" to have shipped the Ames strain to Fort Detrick.
But officials there could also find no evidence of Ames. "The Army said they got it from us," recalled Tom Bunn, head of diagnostic bacteriology there. "But we have no records of this being in our laboratory."
Still, most federal and private analysts concluded that the germ had arisen in Iowa, been isolated at Iowa State, shared with the agriculture lab and from there shipped to Fort Detrick.
By December, analysts were speculating that since Iowa State had destroyed anthrax cultures dating to 1925, perhaps one of those early strains was the true Ames.
Based on that interpretation, Barbara Hatch Rosenberg, a private expert in biological weapons at the State University of New York at Purchase, concluded in widely cited December report that the powdered anthrax in the attack letters "may be a remnant of the U.S. biological weapons program."
But in December, based on interviews and a review of documents, some from Dr. Knudson's file, investigators began to unravel the true Ames story.
Dr. Knudson acknowledges his mistake, saying, "It's good to get this clarified."
Officials at Iowa State could not agree more. Critics had widely faulted the university for destroying its anthrax collection, saying important evidence in the attacks might have gone up in smoke.
"My life would have been a lot easier if it was known as the College Station strain rather than the Ames strain," Dr. Roth said.
Questions linger. An official of Iowa State's veterinary school has been subpoenaed to testify in early February before a federal grand jury in Washington about the school's handling of anthrax germs.
But the discovery of the true history of Ames has raised new concerns in Texas, where the soils appear to be widely contaminated with the lethal strain. In 1997, a goat on a Texas ranch hundreds of miles from the original site of the Ames discovery died from a type of anthrax that turned out to be genetically identical to Ames.
Ames contamination could become a safety issue if would-be terrorists hunt for lethal germs in Texas soils, experts say.
Timothy W. Tobiason, a self-taught scientist who sells germ-weapon cookbooks at gun shows across the West, has suggested that old cattle trails in Texas and Oklahoma are ideal places to dig for anthrax microbes, and scientists say his logic is accurate enough to be dangerous.
"A lot of big cattle drives originated in this area," said Dr. Vickers, the Texas veterinarian who first isolated Ames. "It could be quite simple" for a terrorist to acquire the lethal spores.