What don't we know about the Anthrax attack (but think we know)?


1. We do not know when the first Anthrax attack was launched. Nor do we know its where it was launched. Robert Stevens, the first known victim (and fatality), was admitted to a Florida Hospital on Oct 2, 2001. Since the incubation period can be up to six weeks, he could have been exposed either before or after the September 11th attack. Anthrax spores were found in the mail room of his employer, American Media, and microscopic traces at a local post office, so it is assumed the anthrax that infected him came by mail. But no letter was ever found containing traces of anthrax at American Media, so it is not known when it was sent.

2. We do not know how Anthrax got to the many places, including CBS, Governor George Pataki's secure office, the skin of a child of an ABC producer or the longs of the NY hospital worker fatality. No letter was ever found that related to any of these cases.

3. Although we know the date and proximate origin of the mailing of 3 anthrax-laden letters— the ones to NBC, the NY Post, and Senator Tom Daschle— which were all mailed from the same mail box in Trenton, NJ, over a one week period— we do not know whether or not the person who mailed these letters prepared or even injected the anthrax in them himself or received them in ziplock sealed bags from another source. So they could have been prepared, and even addressed, anywhere in the world.

4. We do not know the precise kind of the anthrax used in the attacks. All the tested anthrax spores are consistent with the virulent Ames strain, but there are many sub-varieties. Homeland Security director Tom Ridge said that the strains used in the Florida, New York and Washington attacks, while "indistinguishable," were not identical. And Anthony Fauci, head of the National Institute of Allergy and Infectious Disease, described the strains as "Ames-like." The problem here is the variations. Each time a bacterium divides, it makes a new copy of its DNA, but with a chance for error in the replication. These cloning errors occur with different frequency in different parts of the DNA, ranging between one per thousand replications to one per 100,000 replications. These samples have not, as yet, been DNA sequenced. If they had been DNA sequenced, the variations could indicate whether they came from a small batch (in which case there would be few changes) or a gigantic batch consistent with a state-run military program (in which case there would be many more changes.) But without such DNA sequencing, we do not have any idea of the size of the batch.

5. We do not know how far the Trenton-NY-Florida variants deviates from the "family tree" of the original Ames strain. As incredible as it sounds, Iowa State University, which was the custodian of the Ames Collection, destroyed its samples right after the Anthrax attack. Neither the FBI or CDC objected to this destruction of this vital evidence (since this lab might have been the source). As a result, it is no longer possible to thoroughly trace the origin of the anthrax in the attack, or determine how many approximate variations occurred in it.

6. Without the Ames Collection, possible sources cannot be excluded:

a) It could have been taken from the Ames strain of anthrax from a US lab, such as Iowa State. In addition to Iowa State only four other labs in America are known to have the infectious Ames strain— the CDC in Atlanta, the US Army Medical Research Institute at Fort Detrick in Maryland, and the labs at Louisiana State University and Northern Arizona University.

b) It could have been a foreign military anthrax program, either known (Britain) or unknown.

c) It could have been taken a dead deer or other animal anywhere in the world.

7. We do not know how the anthrax, was milled fine enough— one 20th of a human hair— to create an aerosol in at least one letter. We therefore don't know what equipment, including separating, freezing, drying, cutting and filtering apparatus, might be needed for the process.

8. We do not know how the anthrax, once milled, was injected into the envelopes.

9. We do not know how many people, if more than one, are involved in the attack

10. We don't know the actual purpose of the anthrax attack. It could be

a) to inflict physical or psychic damage on America.

b) to probe our bio-terrorism defenses in preparation for a larger-scale attack.

c) or, like a kidnapping, to set the stage for a future ultimatum or ransom demand.