American Anthrax Outbreak 2001
FOUR LETTERS FOUND
Four letters laden with Anthrax spores were discovered, all dated by an unknown author as "09-11-01," and all
sent from Trenton, New Jersey. The Federal Bureau of Investigation (FBI) believes all four of the anthrax letters came from
a single individual and were of the "Ames" strain. Two of the letters were postmarked September 18, 2001 in Trenton,
one of which was sent to the New York Post (shown below) where it was handled by several staff members, and the other to Tom
Brokaw of NBC, opened September 19-25 but not found until October 12, 2001 in case 2's file drawer (shown below). The New
York Post letter, handled but not opened, was found on October 19, 2001. It was dampened before being discovered, turning
the spore contents into a granular or clumped state.
The second two letters were postmarked on October 9, 2001 and mailed to the Washington DC offices of Senator Tom Daschle
of North Carolina, Majority Leader (route shown at left, letter shown below) and Senator Patrick Leahy of Vermont, Chair of
the Judiciary Committee (shown below, envelope only). Both letters went though Washington DC's Brentwood mail processing facility,
which handles all incoming federal government mail (see map, 2). Both letters contained the same anthrax strain and were of
the same potency.
The Daschle letter was opened in the sixth floor office at 9:45 am by an aide in the Senator's Hart Senate Office Building
suite on October 15, 2001. It was believed to contain about 2 grams of powder comprised of 200 billion to 2 trillion spores.
Based on nasal swabs, all 18 persons who were in the area of Daschle's sixth floor office tested positive for anthrax exposure,
as did 7 of 25 (i.e, 28%) in the area of the Senator's fifth floor office (an open staircase connected the two offices).
The Leahy letter never arrived at his office.
Instead an optical reader misread the hand-written 20510 ZIP code for the Capitol as 20520, which serves the State Department.
As a result, the letter was routed to the State Department, where it arrived on October 15, infecting a State Department postal
worker (case 20). Shortly thereafter, all mail was isolated and sealed in plastic bags for a latter search.
On November 16, 2001, the Leahy letter was found, then after special preparation, was opened on December 6 in a laboratory
setting (see photo). It contained about about one gram of anthrax, made fresh no more than two years before it was sent. The
contents of the enclosed letter were identical to the wording of the Daschle letter. The anthrax spores in the Daschle and
Leahy envelopes were uniformly between 1 and 3 microns in size, and were coated with fine particles of frothy silica glass.
More investigation is underway.
Also processed at the Trenton, New Jersey postal facility was a small number of letters sent to the Southern Connecticut
Processing and Distribution Center in Wallingford, Connecticut (see map). Here letters arrived on October 11 that had been
cross-contaminated with anthrax spores from the October 9 Daschle or Leahy envelops.
Anthrax spores were found on mail-sorting equipment (see photo) in Wallingford. One letter that went through the Wallingford
distribution center was found in Seymour (see map), nearby to Oxford (see map) where case 23 resided. Likely case 23 was infected
via a similar cross-contaminated letter that came in contact with mail in the distribution center in Wallingford (not discovered).
Most uncertain is the origin of case 22, although there is a connection between case 22's neighborhood and the Trenton,
N.J. post office. A printout from the post office showed that an unrelated letter went to a shop around the corner from case
22's home. This unrelated letter was processed two minutes after the Leahy letter and 18 minutes before the Daschle letter.
Thus the mail sent to case 22 might also have been cross-contaminated with spores from the Leahy or Daschle envelops. Alternatively,
case 22 might have had contact with one or more of the unrecovered September 18th letters following their disposal in Manhattan,
similar to case 19 and case 21. Click here for a graph of possible exposure sources for case 22.
Many months later on March 1, 2002, a final case of cutaneous anthrax arose in Texas in one of several private laboratories
contracted by CDC to analyzed the multitude of environmental samples that emanated from the contaminated letters (addenda).
The lab worker cut himself while shaving, the next day handled an anthrax specimen without gloves, and touched the anthrax
spores to his chin.
SEVEN LETTERS SENT
The person(s) who caused the outbreak probably mailed seven letters containing anthrax spores and similar written messages
from Trenton, New Jersey. Five of the letters were sent on September 18 (postal facilities, cases 3, 4 [probable cross-contamination]),
one going to American Media in Boca Raton, Florida (cases 5 and 7) (not recovered); a second to the New York Post (cases 1,
19, 21) (recovered); a third to Tom Brokaw of NBC News (cases 2, 6) (recovered); a fourth to ABC News (case 8) (not recovered);
and a fifth to Dan Rather of CBS News (case 9) (not recovered). On October 9, two more letters were sent from Trenton, N.J.
(cases 10, 11, 12, 13, 18 [probably cross-contamination]) via Brentwood mail processing facility (cases 14, 15, 16, 17), one
to Senator Tom Daschle (recovered) and the other to Senator Patrick Leahy (case 20) (recovered). Letter(s) cross-contaminated
with the Daschle and Leahy letters were sent from Trenton, N.J. to Wallingford, CT, with at least one letter probably going
to Oxford, CT (case 23). The final anthrax case in the outbreak remains a mystery, but possibly arose from contact with the
September 18 letters or cross-contamination with the October 9 Leahy letter in Trenton, New Jersey. To do so, spores from
the Leahy letter would need to have adhered to an envelop of another letter destined for the Bronx, New York City (case 22).
In summary, the 22 cases (one was removed by CDC) that comprised the American Anthrax Outbreak of 2001 likely had contact
with one or more of seven spore-laden envelopes. A final case, bringing the total to 23 but not considered by Professor Frerichs
to be part of the initial outbreak (see addenda), occurred months later in a Texas laboratory worker following direct contact
with a vial of anthrax spores.
Details on exposure to the letters is included with information on each case.
PERPETRATOR(S) WHO SENT ENVELOPES
While CDC epidemiologists have been able to solve the biological aspects of the detective drama, the person(s) who mailed
the anthrax-containing envelopes remain free. The FBI and detective colleagues have published description information and
theories, and perhaps are closing in on the guilty parties, but so far the criminal agents remains undetected. The focus of
the FBI investigation appears to be on: 1) laboratories that may have supplied the anthrax spores, 2) the Leahy letter which
was preserved in an unopened state, and 3) a profile of the likely suspect(s), based on behavior patterns, intended to stimulate