Frightening as it was, it was not a full-scale catastrophe with a large death toll. But it killed five people and forced the nation to confront a microscopic and unfamiliar foe: anthrax.
Instead of being spread through the air with sophisticated equipment as bioterrorism dooms-dayers might predict, the lethal white powder was delivered in the mail, postmarked Sept. 18 from Trenton, N.J. The letters were addressed to prominent politicians and journalists.
None of the sinister letters written in crude block lettering harmed the intended targets. The victims were postal workers, administrative assistants, congressional staffers and innocent bystanders. Thirteen people who were infected, including a baby, recovered.
The FBI and other agencies have assigned as many as 1 of every 4 investigators to the case. Theories abound about whether the terrorist is domestic or foreign, but there are few clues and, officially, no suspects.
Nor is the crisis over. Traces of the bacteria were discovered as recently as Dec. 6 in a mail bin at the U.S. Federal Reserve in Washington.
Anthrax may not be the weapon of mass destruction as originally feared. But it certainly has proved to be a weapon of mass disruption.
It briefly shut down Congress, sowed panic and has forced security steps costing billions. The crisis has exposed critical gaps in the nation's disease surveillance and emergency management systems that still are being debated.
A vulnerable America finds itself considering a host of previously unimaginable threats.
We're preparing enough smallpox vaccine to inoculate every American against a disease that has been naturally eradicated, but could become the most fearsome biological weapon of all.
Crop dusters were grounded temporarily to prevent terrorists from spraying biological or chemical agents over cities, and poisoning crops. Armed guards were posted at many drinking water reservoirs.
We're irradiating federal mail to kill lingering anthrax spores and prevent more cross-contamination. Many Americans wear gloves when they check the mailbox. Some are avoiding Christmas cards, just to be safe.
Is it sufficient? Necessary? Nobody's sure.
Since early October, each day's headlines have defied what security and public health advisers presumed to know about bioterorrism. Much of what they had practiced in war games and computer simulations turned out to be wrong.
In one week in October, Washington officials went from describing the anthrax in the letters as "garden variety" to "professionally done."
"Experts really have been groping in the dark," said Jonathan B. Tucker, a biowarfare expert at the Monterey Institute of International Studies in Washington, D.C. "Conventional wisdom has been repeatedly challenged."
Assumption: Spreading weapons-grade germs requires sophisticated engineering that only state governments can provide, and the U.S. biologica weapons program is secure.
Fact: Investigators have not found a credible link to any foreign government.
The anthrax in the letters was derived from the Ames strain, a common, very virulent form used in American biological weapons research and in vaccine testing. The anthrax spores themselves were very pure and they were refined to be more effective.
Former Soviet biological weapons designer Ken Alibek told Congress the anthrax letters could have been generated by a Ph.D. microbiologist.
Now the FBI is looking for a "standoffish loner" and a "controlling male" with a scientific background, not unlike Theodore Kaczynski, who was a math whiz before he became the Unabomber. FBI behavior analyst Jim Fitzgerald describes the letters' author as a "biobomber."
Assumption: A victim must inhale at least 8,000 anthrax spores to be infected.
Fact: Not necessarily. In many anthrax cases, the actual circumstances of exposure are unclear, but at least two of the victims had no known direct connection to the dangerous germ-laden letters.
Everyday citizens, 94-year-old Ottilie Lundgren of Oxford, Conn., and 61-year-old Kathy T. Nguyen of New York City, died of inhaled anthrax. Yet, investigators have found no anthrax at their homes or Nguyen's workplace, a storeroom in a Manhattan hospital. Cross-contaminated mail is suspected, but none has been found.
Assumption: Anthrax spores don't scatter without help from an explosion or a sprayer.
Fact: Finely milled spores - treated with an electrostatic charge and chemicals - migrate through the woven fibers of envelopes. The stray spores contaminated sorting machinery at post offices as well as other mail.
In the Hart Senate Office Building, lethal powder in the letter to Majority Leader Tom Daschle spread next-door to the office of Sen. Russell Feingold, D-Wisconsin. Their offices were sealed and fumigated with a chlorine gas as part of a broader cleanup that lasted weeks.
When technicians at the Army biodefense lab in Fort Detrick, Md., tried to examine a sample from the Daschle letter under a microscope, it floated off the glass slide and was lost.
To prevent further leakage, tests on the anthrax letter sent to Sen. Patrick Leahy, D-Vermont, were conducted in a protected glove box under negative air pressure.
Assumption: Inhaled anthrax is a death sentence unless treatment begins before symptoms appear.
Fact: Until Florida tabloid photo editor Bob Stevens fell ill, American doctors hadn't seen a case of inhaled anthrax in 25 years. They discovered that aggressive treatment with a combination of powerful new antibiotics, as well as blood filtering and other techniques, can save some patients.
Time is precious. Washington postal workers Joseph Curseen and Thomas Morris Jr. initially were sent home from hospital emergency rooms. Both died within hours.
Stevens, 63, died three days after going to the hospital.
But his co-worker Ernie Blanco reported similar symptoms ad was immediately treated with antibiotics to prevent pneumonia. Blanco, 73, is a decade older than Stevens, but he recovered.
Congress is considering bioterrorism measures that would authorize up to $3.2 billion to better prepare the nation for future attacks.
Rep. Billy Tauzin, R-La., chairman of the Energy and Commerce Committee, describes it as "a down payment on what we think is necessary to protect this country."
In addition to funding smallpox vaccines, lawmakers are discussing up to $1 billion for states and health care facilities to improve preparedness and train workers; $450 million for the Centers for Disease Control and Prevention to upgrade their labs; $1 billion for the Health and Human Services secretary to expand national stockpiles of medicine and vaccine; $100 million to protect imported food; and $100 million to develop emergency response plans for drinking-water systems.
"We've had 30-plus years of neglect of the public health system and underinvestment in it," said CDC director, Dr. Jeffery Koplan. "If we want to be as effective as we can be, whether it's a bioterrorist threat or an infectious disease, we've got to make that investment."
By Joseph B. Verrengia
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