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View Full Version : More Anthrax Contaminated Letters, And Updated Research



Reasonable Rascal
05-09-02, 23:10
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BBC World News tonight, 9 May 2002, reports that several letters contaminated with anthrax have been detected in recent mail in the Federal Reserve building in Washington, DC. However, these letters have no other suspicious characteristics, & it is thought they may have suffered cross-contamination in a mail sorting location which had not been sufficiently cleaned following the October 2002 episode. - Mod.JW]
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From: ProMEDmail
Date: 8 May 2002
Source: NY Times [edited]
<http://www.nytimes.com/2002/05/07/national/07ANTH.html>


Anthrax Sent Through Mail Gained Potency by the Letter
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Deepening the mystery of the biological attacks that terrified the nation last fall, federal investigators have discovered that the anthrax sent through the mail, in general, grew more potent from one letter to the next, with the spores in the final letter to be opened (the one sent to Senator Patrick J. Leahy of Vermont) the deadliest of all. The finding has surprised and worried investigators, who say it poses a new riddle: was the culprit an amateur making gradual improvements through experimentation, a malevolent professional intentionally ratcheting up the potency of the germ powder, or someone else entirely?

With 5 anthrax deaths linked to the contaminated mailings, the FBI inquiry has consumed millions of hours of interviews, neighborhood sweeps and other detective work. For example, FBI laboratory analysts matched the serrated ends of the strips of cellophane tape used to seal the anthrax letters. That meant that whoever sealed the letters, without leaving any fingerprints, tore off successive strips of tape from the same roll, officials said.

But investigators acknowledge that they still have no idea who is behind the tainted letters. So they are increasingly turning to science to unravel the mystery. Tests being conducted at several private laboratories may reveal the precise biological signature of the anthrax used in the mailings, helping to narrow the search for the laboratory from which it came. Analyses of the anthrax sample and the chemicals used to coat it could yield clues to the techniques and equipment used to manufacture the germ material.

Investigators previously believed that the anthrax sent to Mr. Leahy, the Democrat who is chairman of the Senate Judiciary Committee, and Tom Daschle, the Senate majority leader, were identical in strength. Each letter was mailed from Trenton on 9 Oct 2001. Each had the same photocopied message inside.

But it turns out that the Leahy anthrax is finer, its spores having a smaller range of particle sizes, officials familiar with the federal investigation said. "It could be that the final steps of the processing were done in steps," a senior government official said. "You take it so far, and take off a bunch. You go further, and take off another bunch."

Despite the increasing sophistication of the anthrax, investigators say they still judge that the deadly powder could have been made in any of thousands of biological laboratories, though getting the right starter germs would have been difficult.

An aide to Senator Daschle opened the letter on 15 Oct 2001, and officials quickly warned that its anthrax was of high quality compared with earlier mailings, to news media offices in New York. The Leahy letter was impounded, along with all other Congressional mail, and was not discovered until 16 Nov 2001. Investigators made painstaking safety and forensic preparations before opening it in early December 2001.

The analysis of the contents of the Leahy letter is proceeding slowly, the investigators say, because they are learning the science as they go along and want to make sure that none of the scarce, lightweight, but extremely valuable evidence is lost, corrupted, or misinterpreted. They are getting help, they say, from scores of scientists across the nation. "We'll have to take this into court," the law enforcement official said of the evidence. "We had to assure ourselves that we had a quality program."

A senior Bush administration official expressed sympathy for the FBI because the inquiry had grown so scientifically complex and knowledgeable advisers are so few. "They're having to review a lot of the initial takes on things," the official said. "There's an evolving picture. The bureau has gone back to scratch to invent the science."

It is sometimes hard even to do reappraisals. In the Florida case, no letter or residual powder was ever recovered, leaving many questions about the anthrax there.

Federal officials said the first wave of well-documented attacks with mailed anthrax - in letters from Trenton postmarked 18 Sep 2001 to NBC News and The New York Post - was relatively crude. The powder was heavily contaminated, they said, with what biologists call vegetative cells - anthrax bacteria before processing in the laboratory turns them into hardened spores. Vegetative cells in dry anthrax powder are generally dead and therefore harmless, experts said. By contrast, the tiny spores live in a dormant state. Individual ones are light enough to float easily in the air and, if inhaled, small enough to reach deep into human lungs, eventually germinating into bacteria and causing the respiratory form of the disease, which can be fatal. They can also cause the less dangerous cutaneous form if rubbed into the skin.

In October 2001, alarm bells rang when the Daschle powder was found to be nearly pure spores. The danger was driven home when nasal swabs came back positive for 28 people in the Senate Hart building, where the letter was opened. The FBI in early November 2001 characterized the Daschle powder as "much more refined, more potent, and more easily dispersed" than the New York media anthrax. The mailer's letters hinted at the danger. The media ones warned the openers to take penicillin. But the Daschle letter said flatly, "You Die Now."

As federal experts investigated the residual Daschle sample, they found the picture becoming fuzzier. On one hand, the concentration of the anthrax was extraordinarily high - roughly equal to that made in the abandoned American germ weapons program, a trillion spores per gram. But federal experts now say the particles turned out to have a large size range. While single spores predominated, the experts said, some Daschle clusters ranged up to 40 microns wide - far too big to penetrate human lungs. A micron is one-millionth of a meter, and a human hair is 75 to 100 microns wide. The big clusters suggested the powder was far less than weapons grade.

Private experts disagree on just how much less. Ken Alibek, a former Soviet germ official who is now president of Advanced Biosystems, a consulting company in Manassas, Va., called the Daschle anthrax mediocre. "It was not done with a regular industrial process," Dr. Alibek said in an interview. "Maybe it's homemade." Recipes that antigovernment militia groups circulate at gun shows might suffice to make the deadly powder, he said.

But William C. Patrick III, a scientist who made germ weapons for the American military and is now a private consultant on biological defense, rated the Daschle anthrax as 7 on a scale of 10. "It's relatively high grade," Mr. Patrick said, "but not weapons grade."

In addition to particle size, federal experts are investigating whether the anthrax powders have electrostatic charges that affect dispersal and chemical coatings meant to increase potency and shelf life.

Federal investigators saw the Leahy anthrax as an opportunity to clear up ambiguities and deepen the analysis. Since no powder had been lost in the letter's opening, they had more to work with. Still, the amount, typical of the tainted letters, was remarkably small - just 0.871 grams. A pat of butter weighs 10 grams.

Last week, government officials said the most recent analyses showed that the Daschle and Leahy powders were quite different, the latter finer and more uniform. "You can characterize the Leahy as having a smaller particle range," one official said.

A biologist aiding in the investigation said the increasing potency of anthrax in the letters might suggest that the attacker was a thief who stole several samples. "Maybe he didn't pocket one vial but 2 or 3, if
we're assuming this was an opportunist," this scientist said.

Dr. Alibek raised another possible factor. The FBI, he said, needed to weigh the possibility that Post Office sorting machinery might have had an effect. "It could be an additional process of milling," he said, "like a mortar and pestle." Experts said the Daschle and Leahy letters, starting at the same place in New Jersey on the same date and ending up at the same destination in Washington, appear to have taken similar if not identical postal routes. Dr. Alibek agreed but said the same sorter could apply more pressure to one letter than another. He added that the overall grade contrasts were probably caused by "different batches of the product, one more sophisticated than the other."

Investigators have also been studying the envelopes, officials say, and have found that the paper had very large pores - up to 50 microns wide. That is bigger than the largest Daschle anthrax clusters and suggests how the powder could easily escape individual letters to contaminate the general mails. "It had to be one of the most porous materials," an official said of the attack envelopes compared with standard ones. "Whether that was by chance or design, I have no idea."

[Byline: William J. Broad and David Johnston]
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Posted under Fair Use for Education doctrine

Reasonable Rascal
05-09-02, 23:24
This latest report just invites discussion. It seems that all we know about anthrax - how it works, what the biological mechanism is whereby it causes death, how easily it may or may not be spread - is changing every day.

Within the medical/scientific community there is much disagreement as well as wonderment at how little we actually knew about this disease. With every report on the investigation into the anthrax letters we seem to find more puzzles than answers. It was better than weapons grade, it was less than. It takes fewer spores to cause the disease than we thought, it doesn't take fewer, just smaller. It was extremely sophisticated, it could have been home-grown.

One observation from all of this thus far: if this illustrates how capable we are of determining pathogenicity and appropriate counter-measures for one bio-agent alone, and one which we had previously thought we understood relatively well, how much worse might we be if in the future lesser known bio-agents are used maliciously?

This new era of bio-terrorism crosses all the boundaries of specialism. From EMS to nursing to physicians of various and widely divergent specialties we will all have to change our way of thinking in the future. We may have (infectious) disease, criminal evidence preservation, public health issues and national security issues all combined in each and every case, meanwhile facing widespread panic and shortages of antibiotics, vaccines, and just basic hospital isolation beds in a true widespread attack. And for once, the at-risk factors may change at a whim.

RR

Reasonable Rascal
05-18-02, 17:01
From: ProMED-mail <promed@promedmail.org>
Source: ABC / reuters (edited)
http://abcnews.go.com/wire/US/reuters20020513_427.html


Study: Cross-Contamination Explains Anthrax Deaths
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WASHINGTON (Reuters) - As many as 5,000 letters may have been cross-contaminated with spores from anthrax-laced letters sent in attacks in the United States late last year, experts said on Monday. That cross-contamination can explain the deaths of 2 women, they said in releasing a mathematical model showing how spores from letters sent to news organizations and U.S. senators last year may have transferred onto other pieces of mail and infected the pair. "If there were ever another outbreak this could help us more rapidly control it and maybe more quickly identify where it is coming from," Dr. Martin Blaser, a professor of medicine and microbiology at the New York University School of Medicine who helped write the study.

The letters are believed to have infected at least 18 people and to have killed 5 of them. Another 4 cases of suspected skin, or cutaneous, anthrax infection have not been confirmed. More than 10,000 people including postal workers and Capitol Hill staffers took antibiotics to prevent infection in case they were exposed, and this step saved lives. The greatest danger from the attacks was probably not to the people the letters were addressed to, but to postal workers who handled the mail and to people who got cross-contaminated mail, Blaser said in a study published in the Proceedings of the National Academy of Sciences.

Blaser and Glenn Webb, a professor of mathematics at Vanderbilt University in Nashville, Tennessee, came up with the model after the letter attacks in October. The U.S. Centers for Disease Control and Prevention has assumed that mail cross-contamination was to blame for the deaths of the 2 women, but Blaser, an adviser to former New York mayor Rudolph Giuliani on bioterrorism even before the attacks, said it was not clear at first. He said he figured it out when the second woman died in November.

Blaser and Webb developed a mathematical model based on the number of anthrax letters and how many "nodes" -- such as a mailbox or a sorting center -- they passed through. "As the contaminated letters travel through the nodes, there is a probability that they may transfer spores to other letters, and thus proliferate the number of contaminated letters in successive generations," they wrote. For instance, letters addressed to U.S. senators contaminated a post office in New Jersey, affecting postal workers there.

"In a less than one-minute period, 300 letters passed through the same sorting machines as each of those two original contaminated letters. These 600 letters (and more) were most likely first-generation cross-contaminated letters," they wrote. "One was found to have gone to a recipient in Seymour, Connecticut, who lived about a mile from the 94-year-old woman in Oxford, Connecticut who died of inhalational anthrax on November 21." She was probably infected by a "second-generation" cross-contaminated letter, they said.

"There was also an issue early on about how many spores did it take to infect a person," Blaser said. "Our model presumes that there is no one magic number." Noting the 2 women who died were elderly, Blaser said older people in general have weaker immune systems and are probably more susceptible to inhaled anthrax.

"The rapid and widespread usage of antibiotics among postal workers and persons in the immediate environment if the received original letters probably averted a substantial number of cases," they wrote. It may be worth vaccinating postal workers, they added.

"If there were another outbreak and cases started turning up in different localities, the model could be used to work backward to identify the groups of people who need to receive antibiotics or vaccine," Blaser said.

Last March a team at the Johns Hopkins University School of Public Health in Baltimore did calculations that showed at least nine more cases of inhaled anthrax infection would have occurred if people had not been given antibiotics.

[Byline: Maggie Fox]
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Reproduced under under Fair Use for Education doctrine.