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15 Nov 2002

Source: New York Times, December 26, 2001.

Tracking Bioterror's Tangled Course

There was no commotion, no outcry. Except for the blond woman in the black dress sitting by herself in a back pew, no one knew that anything unusual had happened.

Johanna C. Huden, a 31-year-old editorial assistant at The New York Post, had first noticed the strange blister on her right middle finger the day before, Sept. 21. She had not thought too much about it; surely it was just a bug bite or a cat scratch.

Now, though, as she sat in the Long Island church, half-distractedly watching the wedding ceremony, the finger began to itch. She reached down and rubbed it gently against the coarse linen of her dress. Suddenly, a watery white liquid bubbled out across the cloth.

"Ee-yew," Ms. Huden recalls saying to herself. "That is just really bizarre."

The conventional understanding of America's first-ever anthrax attack says Ms. Huden was a bit player -- a victim of skin, or cutaneous, anthrax who fully recovered and got on with her life. As anthrax spores spread through the mail, and events blurred across six states and the District of Columbia, hers became no more than a name in the middle of a long list of victims.

Yet the conventional understanding is wrong. In the light of hindsight, scientists can now see that the outbreak actually began that September afternoon.

Ms. Huden was the anthrax index patient -- the pivot point upon which every outbreak investigation is based, the crucial clue that every medical investigator hopes can be found, and fast. But on that muggy day at Mary Immaculate Church, she suffered her mysterious wound very much alone.

No one knew.

Those words have become the theme of the medical investigation of the anthrax attacks, a refrain of epidemiological regret.

Certainly, the medical investigators have done much to contain the outbreak and save lives. Yet the inside story of that inquiry -- pieced together from interviews with many of the lead investigators and other health-care officials -- is also a tale of missed cues, misread evidence and erroneous assumptions that led scientists and decision makers to misjudge the threat to postal workers and, through the mail system, to the American public.

For weeks, primary-care doctors individually struggled to diagnose a disease they had never seen and never imagined they would see. In that uncertainty, medical investigators could never quite discern the sequence of infection that began with Johanna Huden. And only through the bitter experience of 5 deaths and 18 other confirmed or suspected cases did they learn how much they did not know about how anthrax spores traveled and infected their victims.

Of course, the medical inquiry is just one of several intertwined strands of the government's still unresolved investigation of the attacks. In recent weeks, in fact, the other aspects have taken center stage, as microbiologists try to pinpoint the nature and source of the mailed anthrax and criminal investigators search for a suspect.

But underpinning those efforts, at every point, are the epidemiologists, the medical detectives on the ground, tracing how the infection spread and whether the underlying pattern of cases can offer up some revelatory clue from the haze.

They can see now that Johanna Huden arrived first in that place of fear and fog. For weeks after the wedding, despite repeated visits to doctors and emergency rooms, her infection worsened and the cause of her illness was missed. And no one knew.

Florida: A First Case To Investigate

Every disease outbreak tells a detective story. The epidemiologist's job is to piece together the narrative threads -- to work back to the beginning and so hasten the end.

Assume nothing; let the evidence speak for itself. That gumshoe credo was very much on Dr. Bradley A. Perkins's mind as the chartered jet roared toward South Florida on the afternoon of Oct. 4, carrying his 12- member team from the Centers for Disease Control and Prevention in Atlanta.

Dr. Perkins, a boyish-looking 42, chief of the centers' special pathogens branch, sat at a small conference table, chatting with the adrenaline-pumped scientists and passing around the latest papers on anthrax. But mostly he tried to concentrate on telling himself not to think about terrorists.

Everyone at the centers, of course, had been worrying about just that since Sept. 11 -- planning for attacks of everything from sarin gas to smallpox to anthrax, perhaps the most widely developed bioweapon in history. But at that moment, all anyone knew was that a tabloid newspaper editor named Robert Stevens was dying of inhalation anthrax in a Palm Beach County hospital.

Perhaps Mr. Stevens had been infected deliberately -- the first periscope glimpse into a mass bioterror attack. Perhaps. It was also possible that the bacteria had been picked up naturally, from a sick cow, even one long dead; anthrax spores could lie dormant in the ground for decades.

For now, this was just a medical case, though Dr. Perkins knew well that on his word a huge criminal investigation would be unleashed. The fear of being wrong was intense. "You don't pull the bioterrorism trigger lightly," he would say later.

Let the evidence speak for itself. That's how epidemiology had always worked. It was a rhythm of science, intuition and observation -- an art essentially unchanged since the 1850's, when a doctor named John Snow stunned the medical world with the insight that every family with cholera in his London neighborhood drew water from the same pestilential well.

Dr. Snow took off the well's pump handle and became a legend. His cholera-cluster maps became the motif of a new science, premised on the belief that disease, in the dawning age of the germ theory, could be chased from the shadows of superstition and hunted to the ground.

Now, flying to Palm Beach, Dr. Perkins and his team planned the hunt for the handle of this latest pump. They would meet with county health officials, then fan out, testing as they went -- Mr. Stevens's home, office, whatever made sense -- with swabs that would pick up any errant anthrax spores.

By the time they landed, Dr. Perkins felt satisfied that he had pushed as hard as he should the admonition to leave no stone, quite literally, unturned.

But then, leaving the airport, he saw something that tested his assumptions all over again. Flight Safety International, the pilot school where some of the Sept. 11 hijackers were thought to have trained, had a flight simulator right at the airport. Could it be coincidence that here, of all places, and now, of all times, anthrax would just happen?

As he drove his rental car past the building, he had more or less the same thought that had flickered across Johanna Huden's mind two weeks before.

"This is weird," he said to himself.

The Northeast: Though Unreported, Patients Accumulate

Actually, up North, seven people were already mysteriously ill.

Teresa Heller, a letter carrier assigned to West Trenton, N.J., had checked into a hospital with an infection on her arm.

Richard Morgano, a maintenance worker at the mail distribution center in nearby Hamilton Township, had a similar lesion on his arm.

In Manhattan, the infant son of an ABC news producer was in a hospital, gravely ill with a high fever and an ulcerated arm.

Erin M. O'Connor and Casey Chamberlain, assistants to the NBC News anchorman Tom Brokaw, had skin lesions -- Ms. O'Connor on her collarbone, Ms. Chamberlain on her leg.

Claire Fletcher, a CBS News aide, had two small infected pimples on her face.

And Johanna Huden had been to two emergency rooms and seen more than half a dozen doctors. Ultimately, on Oct. 1, a surgeon at New York University Medical Center had cut the dead skin out of her finger. Ms. Huden left the hospital with a large bandage on her hand but no better idea of what had made her sick.

None of those cases -- misdiagnosed and misunderstood -- were reported into the medical surveillance system on which epidemiology depends.

Without realizing it, Dr. Perkins and his team were starting in the middle. The Stevens case, they believed, was the index case. And that misperception was the first of many to guide the investigation -- in Florida and then up North -- in the coming days.

The next morning, Oct. 5, the scientists fanned out, checking things out, including the vacuum-cleaner bags in Mr. Stevens's house and the ventilation system on the roof of the American Media International building, where he worked.

They went to a store where he bought spices in bulk; the store kept live animals, they had been told, and had to be checked as a possible source of natural contagion. They visited his favorite fishing hole and traced his Sunday bicycle route. A separate team went to North Carolina, where Mr. Stevens had first felt ill while visiting his daughter.

All trails led nowhere. The dead-cow vector, even as a remote hypothesis, faded. Mr. Stevens died that day, unable to help them.

Various pieces of evidence, though, eventually pointed toward the company's mailroom. Tests of a mailroom worker, Ernesto Blanco, hospitalized with a still-undiagnosed illness, turned up an anthrax spore in his nasal passage. Spores were also found on Mr. Stevens's computer keyboard.

But when the investigators first arrived in the mailroom late on the afternoon of Oct. 5, they realized to their horror that, in their exuberance or thoroughness, they had used up all but one of their cotton swabs.

One small swab to test the whole room -- it seemed like the wildest shot in the dark.

So the scientists stood amid the postage meters and scales and argued the point: Though they could get more swabs, this was it for the day, and at a time when every hour felt laden with portents and pressures, the decision seemed enormous. Finally, they decided to use the last swab on a bin holding letters and packages for the photo department, where Mr. Stevens had worked.

The results came back the next day with a direct bull's-eye. The mail bin was heavily contaminated, and the conclusion, Dr. Perkins said, was unmistakable: Mr. Stevens had been the victim of a criminal act.

The finding sent a shock wave through the nation and changed everything about the case. This was not simply a medical investigation anymore. The F.B.I., which, like the disease control centers, had been preparing for bioterror attacks since Sept. 11, took over.

For the epidemiologists, the discovery was as if a fog had lifted just long enough to see that they were headed out into uncharted, and uncomfortable, territory. They were not just hunting an organism with genes and biological logic that could be tracked the traditional way. This was a weapon, deliberately wielded, with an exponentially increasing number of possible sources. That mixture --- the biological and the psychological, the genetic and the perversely pathological -- fundamentally altered the task at hand.

"Usually we're talking about trying to define normal biologic transmission," Dr. Perkins said. "This is a terrorist transmission route."

Investigators followed that route from the mailroom to the delivery truck, to the Boca Raton post office and through the county's mail system, finding spores all along the way.

What they did not find were any sick postal workers. They had no reason to connect Mr. Stevens to Teresa Heller and Richard Morgano and the others up in New York, because they did not yet know they existed.

The postal system, they now knew, had been used as an instrument of attack, an important finding. But it went only so far. Since no postal workers seemed even remotely affected, the postal connection was treated as one clue among many, not the sure, single pathway suffused with risk.

On Oct. 9, President Bush told an edgy nation that the Florida case appeared to be "an isolated incident."

But Dr. Perkins, the epidemiologist, recalls feeling "extremely uncomfortable."

"We know someone is out there with the ability to cause disease, but we don't know how much mail is out there or whether the mode of delivery is going to change," he recounted. "We're operating on data that are inadequate for the situation."

New Jersey: Delayed Recognitions Of Cases Missed

"You heard about Hamilton?"

That was the question Dr. Michael Dash's wife yelled out as he arrived home Saturday afternoon, Oct. 13, on what was to have been a quiet weekend with the family.

She had been checking the headlines on the Internet that afternoon when she happened upon a news bulletin: an anthrax-laced letter had been found in New York that had been postmarked at the Hamilton Township mail- sorting center near Trenton.

"Oh no," Dr. Dash thought after reading the story. "That is what that man had."

That man was Richard Morgano, 39, a barrel-chested maintenance worker at the Hamilton postal center, who had come into Dr. Dash's New Jersey office on Oct. 1 with a strange infection.

Mr. Morgano had scratched his arm on Sept. 20 while reaching into a Hamilton mail-sorting machine. A blistered wound had formed, oozing a yellowish liquid around back spots of dead skin. His arm was twice its normal size, his lymph nodes swollen and his hand unbendable.

At that first meeting, Dr. Dash put Mr. Morgano on a strong dose of antibiotics and, after checking a reference book, asked Mr. Morgano a line of questions fearing he was facing a condition he had never before seen.

"You doing any hunting recently? You've been working with pelts? Been around goats or any farms?" Dr. Dash asked, checking possible natural causes of anthrax.

But Dr. Dash had never imagined that a postal worker in central New Jersey would be the victim of a terrorist attack. So when Mr. Morgano answered "no" to each of the questions about natural sources of anthrax, Dr. Dash had ruled it out.

Dr. Dash was far from the only physician who had a sudden and disturbing realization that weekend. The discovery in New York of the anthrax-contaminated letter, which had infected an NBC News employee, evoked a series of calls to local and federal authorities in New York and New Jersey.

In fact, on the same day Mr. Morgano was at Dr. Dash's office, Ms. Huden and the ABC producer's baby were just eight floors apart at the New York University Medical Center.

"I kick myself when I think about it now," Dr. Douglas Yoshia, the attending physician on duty when Ms. Huden showed up at the emergency room.

Like Dr. Dash, upon hearing about the NBC case and the Hamilton letter, Dr. Yoshia immediately realized Ms. Huden had had anthrax. But he had one more complication to overcome: He could not remember her name. It took a few days of searching through hospital records to track it down and by the time he reached Ms. Huden, her case was already being investigated.

It was only once these cases bubbled to the surface that the true pattern of the outbreak started to become apparent. And, perhaps most important, health officials now had hard evidence that postal workers were, at a minimum, at risk of cutaneous anthrax.

Even so, the full significance of this discovery was not initially recognized. It took five days to confirm that Mr. Morgano and Ms. Heller, the West Trenton letter carrier, had anthrax.

By Oct. 18, when these cases were confirmed, seven other postal workers -- three in New Jersey and four in Washington -- had begun to feel sick, most with the more serious version of inhalation anthrax. The second wave was under way, this time from poisoned letters postmarked at Hamilton on Oct. 9 on their way to Capitol Hill.

In this wave, a few of the cases would be identified quickly, and the postal employees would recover. But again, some doctors who encountered these sick postal workers would not make the anthrax connection. And this time, the implications would be fatal.

District of Columbia: The Medical Becomes Political

It was still dark and silent that Saturday morning, Oct. 20, when Dr. Michael S. A. Richardson picked up the telephone in the hallway of his Washington townhouse to call the office. During the night, he had received a message on his new cellphone -- issued to go with his new job as an acting senior deputy director at the District of Columbia Department of Health -- but no one had taught him how to retrieve messages.

Now, as he realized what he had missed during the night, he stretched the phone cord into the living room, perched on the arm of a chair and scribbled notes as fast as he could.

A worker at the Brentwood Road postal center in Washington, Leroy Richmond, had been tentatively diagnosed with inhalation anthrax. The implication was staggering.

"We are in the middle of this," Dr. Richardson recalled thinking. "And it's a huge deal."

Washington is where the anthrax story became political, social, even racial, theater. And it is where the assumptions of the investigation -- woven from decades of conventional scientific wisdom and weeks of evidence and missed cues -- all unraveled.

When he picked up the phone that morning, Dr. Richardson did not know about the second wave. What he -- and the rest of the nation -- did know was that just five days earlier, on Oct. 15, an anthrax-laced letter had been opened in the Capitol office of Tom Daschle, the Senate majority leader. And though reports conflicted, suspicions ran deep -- and had been played in banner headlines -- that the material in this letter was dangerously different. Many of the government's bioweapons experts were saying that the anthrax spores seemed much smaller, perhaps capable of staying airborne longer, and thus far more likely to penetrate deep into the lungs.

Even so, Dr. Richardson knew of no postal worker who had developed the life-threatening inhaled form of the disease, despite the trail of spores across the postal system. And the disease control agency had said that only people in the immediate vicinity when a poisoned letter was opened were at risk.

Dr. Richardson also knew that an initial test at Brentwood Road, where the Daschle letter had been processed, had turned up no evidence of contamination. And there was the curious case of the worker at the P Street station, who had tested positive for inhalation-anthrax exposure immediately after the Daschle letter, but then, after retesting, was put back on the negative list. Both those results seemed to reinforce the conventional wisdom.

Now it was all dreadfully wrong. Postal workers were in direct and dire danger. Sealed envelopes could leak. The inhalation case at Brentwood had presented, literally overnight, a new signature of threat.

What was clear, too, was that the full implication of tinier, airborne spores had not been thought through; early hints, like the P Street worker, had become missed opportunities rather than signal flares suggesting that more testing might be needed. In Atlanta, it would be another week and a half before the C.D.C. opened what turned out to be a very prescient e-mail -- a warning from Canadian researchers, sent Oct. 4, that tests had shown that anthrax spores could leak through envelopes.

Dr. Richardson has no illusions that an earlier grasp of the dangers of the Daschle anthrax could have kept Mr. Richmond or the three other infected Brentwood workers from getting sick; they had already been exposed. But it might have meant faster diagnosis and faster treatment. With physicians on the alert, the words "I work for the postal service" would have opened doors and minds in doctors' offices everywhere.

"Everybody and their mother would have known that a postal worker is potentially at risk," Dr. Richardson said. "And so that famous tape of this man Morris, saying that he went to his doctor and the doctor told him don't worry, would probably not have happened." Thomas Morris Jr., a Brentwood worker, died on Oct. 21; Mr. Richmond recovered.

The flawed assumptions had other consequences. Because postal workers had not been considered at risk, only people at the Capitol were tested and given the anthrax antibiotic Cipro after the Daschle letter was opened. Now, Dr. Richardson saw, a huge intervention -- running late and behind the curve -- would have to begin.

And in Washington, where conflicts of race and class simmer even in the best of times, a late start would have its own costs and consequences.

The city's health commissioner, Dr. Ivan C. A. Walks, faced it first-hand when the congregation at an African-American church peppered him with questions about why postal workers, many of them black, were being treated differently than people at the Capitol. While some postal workers ultimately were tested with nasal swabs, the process was stopped, epidemiologists said, because the technique was unreliable.

" 'The folks on the Hill got swabbed, now you're not swabbing us,' " said Dr. Walks, who is black, recalling the uncomfortable questioning in the church. " 'White people got swabs, black people didn't get swabs.' "

People also questioned the switch from Cipro to doxycycline -- a far less expensive, but equally effective, antibiotic.

"The white folks got Cipro -- we're getting doxy," Dr. Walks said, replaying the exchange. "They got the expensive drug -- you're trying to save money with us."

It was not just a matter of anger. The shifting understanding of anthrax also created doubt about just how much the epidemiologists should be trusted or believed.

Dr. Richardson saw the doubt that Sunday night, as health officials distributed antibiotics to postal workers downtown. Around 10 p.m., Dr. Richardson was approached by a distraught man who said the disease agency was wrong to believe that only a directly poisoned letter was a threat. The man said he worked at Brentwood and knew how mail got tossed around in the sorting machines.

"You don't know, it's not one place, things get mixed up," he said. "There has to be cross-contamination." In other words, even mail that came in contact with poisoned letters might not be safe.

"I had no idea what he was talking about," Dr. Richardson said. He told the man to share his information with the C.D.C.

Atlanta: Debating Public Policy At the C.D.C.

The national cerebrum of the anthrax crisis was a small conference room at Centers for Disease Control headquarters plastered with bioterror versions of Dr. Snow's cholera maps. There were detailed floor plans of newsrooms and Senate offices, and now, the shop floor at Brentwood Road, all color-coded to indicate the different paths the spores had traveled.

Most of the room was taken up by a rectangular table with a speakerphone that linked the center's scientists with the other players in the investigation -- the F.B.I., the postal service, the homeland-security bureaucracy and local law-enforcement officials across the nation. The scientists found themselves exercising some unfamiliar mental muscles. Dr. Perkins says he thought that a Cliff Notes compendium of fictional bioterror plots would have come in handy.

It was in that conference room, on Monday, Oct. 22, that centers officials began debating what they say were among the most difficult questions the agency had ever addressed: Was the postal system itself contaminated? Should it be shut down? Such a decision, the officials knew, would rip through the economy, not to mention the delicate psyche, of a nation under siege.

"Is there a health hazard here of such a magnitude that it would warrant that type of action?" asked Dr. Julie L. Gerberding, the centers' acting deputy director of infectious disease, who two decades before had seen the AIDS epidemic emerge in San Francisco.

The magnitude of the anthrax hazard certainly seemed to be growing. Two Brentwood workers had died; two others were in intensive care. In New Jersey, a postal worker appeared to have the state's first case of inhalation anthrax. Four days earlier, state health officials closed the Postal Service's regional distribution center near Trenton.

But there was also a conundrum underlying the debate. In an atmosphere of rising crisis, Dr. Gerberding and others felt huge pressure to act decisively, even as events in Washington had made it clear to them that decisiveness was hardly warranted.

What's more, they were in an unaccustomed, and uncomfortable, position of power. While the agency could only recommend shutting the system down, officials knew their advice would carry great weight. The debate became a test of leadership, science and nerve, all bound together by constant stress and sleepless nights.

Dr. Walks, the Washington health commissioner, who participated in some of the discussions by speakerphone, said it had become hard to discern the line between the need to be confident and the need to be right.

More than once, he said, as he stood alongside public officials at news conferences in Washington in mid-October, he inwardly groaned because old answers about anthrax were still being given and he realized that even information a week or two old could no longer be trusted. Some officials were still saying, for example, that a certain number of spores -- 8,000 to 10,000 was the commonly quoted figure -- were needed to contract inhalation anthrax. Given what was now known about the dangers for postal workers, perhaps that old assumption was no longer true either.

"I think it's time for us to stop needing to say we know and let people know what we don't know," he recalled thinking at the time. "Because if we don't do that they won't believe us when we come to say we know stuff, and that's critical."

The verdict was to keep the system open not because it was deemed clean and uninfected, C.D.C. officials said, but because there simply was not enough evidence of widespread contamination. The finding did little to ease anxieties, though. Closing the system would have affected millions of people; not closing it might, too.

New York: A New Victim. A New Wave?

Dr. Stephen M. Ostroff's darkest hour came sometime before the dawn of Oct. 30. New York, he'd come to believe through a long, sleepless night, was under attack, and as the chief epidemiologist at the C.D.C.'s National Center for Infectious Diseases and the agency's point man for the city, the list of things he didn't know seemed endless.

"It was my worst moment," he said.

He had just learned from the city's Department of Health that a 61-year-old stockroom clerk at a Manhattan hospital, Kathy T. Nguyen, was on a respirator and declining quickly from inhalation anthrax.

Part of Dr. Ostroff's anxiety stemmed from the fact that Ms. Nguyen -- the city's first inhalation case -- fit no previous pattern. The first wave of anthrax-contaminated letters in mid-September had been aimed at news organizations; the second in early October had been sent to political leaders. Was she the sentinel patient of a third wave, focused on the health care system?

But he was also haunted that morning by the long shadow of Washington, and the presumptions that he and other epidemiologists had been so wrong about. Dr. Ostroff had been one of those playing down the threat to postal workers from sealed letters. "None of us, to our eternal dismay, would have ever imagined that an unopened letter could do what they did," he said. Would Ms. Nguyen's illness reveal yet another missed link in the chain of reasoning and evidence?

Dr. Ostroff was hardly a novice. In 15 years at the disease control agency, he was one of the agency's most trusted detectives, helping to respond to the outbreak of hantavirus among American Indians in the Southwest, West Nile virus in New York, Ebola in Reston, Va.

Now, on the morning of Oct. 30, preparing to help the city respond to this new threat, Dr. Ostroff anxiously arrived at City Hall so early that the night-duty police officer had to let him in. He was escorted to the mayor's anteroom, where he fell asleep on a couch. The mayor woke him up when he arrived for the 8 a.m. meeting about the Nguyen case.

"We are about to see a lot of sick people in New York," Dr. Ostroff kept thinking.

New York -- hardest hit by the Sept. 11 attacks -- still seemed deeply vulnerable, both to attack and to panic. The city's health department, only a few blocks from the still smoldering ashes of the World Trade Center, had been intently preparing for a bioterror attack that might send tens of thousands of acutely ill people to city hospitals all at once.

But as the inquiry intensified, the mysteries only deepened. Investigators could not find even a single spore of anthrax near Ms. Nguyen's home in the Bronx, or at the Manhattan Eye, Ear and Throat Hospital, where she worked. No one else got sick, which eased anxieties at the health department but also added to the sense of incomprehensibility.

Ms. Nguyen, who died Oct. 31, was not the harbinger of a feared new mass attack -- but neither, it seemed, would the evidence about her infection provide the break in the investigation that Dr. Ostroff and others had hoped for. One F.B.I. theory had been that Ms. Nguyen might have crossed paths with the bioterrorist. Now, all they knew for sure was that she had somehow been infected with anthrax in a place health officials could not find and in a way that had left no trace.

Connecticut: Revising the Textbook, One More Time

Dr. Joxel Garcia, Connecticut's health commissioner, had been working almost nonstop for six days to unravel the death of Ottilie Lundgren, the 94-year-old widow from Oxford, Conn., who on Nov. 21 became the nation's fifth fatality -- and his state's first -- attributed to inhalation anthrax.

Investigators had been sent to her favorite neighborhood dinner spot, her hairdresser, her bank, her church, her library and, of course, her local post office and her home. Nothing so far had turned up.

But on the evening of Nov. 27, Dr. Garcia's staff had made a discovery that at first seemed like wild coincidence: An 85-year-old man who had lived in the town of Seymour, about a mile and a half from Mrs. Lundgren, had also recently died. And he had lived right next door to a family that Postal Service officials said had received a letter postmarked in Hamilton, N.J., at nearly the same instant that the toxic letter to Senator Daschle had been processed.

Perhaps, this new evidence suggested, a letter that merely crossed paths with an anthrax-laced envelope could pick up enough spores to kill. If so, maybe that was how Mrs. Lundgren caught the disease, and her elderly neighbor, Oscar B. Haines -- and Ms. Nguyen in New York as well.

The implications were disturbing. Hundreds of thousands of letters -- perhaps millions -- had passed through the postal system since the anthrax mailings, and might now be contaminated with small amounts of anthrax that, if the theory held, might be lethal under certain conditions.

Dr. Garcia immediately called Gov. John Rowland, then the F.B.I., then the state's chief medical examiner. The first question on everyone's mind was as ghoulish as it was simple: Where was Mr. Haines's body now?

An F.B.I. agent and three state epidemiologists were dispatched to wake up the Farkas family, which had received the Hamilton letter, and swab their mailbox for spores. H. Wayne Carver II, the chief state medical examiner, tracked down the funeral home director who had Mr. Haines' body and ordered it sent over immediately to the state laboratory for examination.

Two months after the first anthrax victims like Ms. Huden had suffered in anonymity, the nation's sprawling investigation had come to this: a desperate search in the night for the body of a man who might or might not have had the disease, and who in any case could no longer be helped, but who might still bear silent witness for the prosecution.

The autopsy, begun at 2:47 a.m., revealed that Mr. Haines did not have anthrax. His heart had simply failed. Dr. Carver called Dr. Garcia at about 4 a.m. with the news.

But when the investigators arrived at the Farkas's house on Great Hill Road in Seymour, they found to their astonishment that the letter postmarked in Hamilton on Oct. 9 had, for other reasons, been saved.

By Nov. 30, the investigators had the results -- the letter was positive for spores, and the news quickly spread out across the United States, once again changing the state of science about anthrax.

Cross-contamination was definitely possible. An innocuous letter, passing through the labyrinth of the postal system at the wrong moment, could become dangerous, as the Brentwood postal worker had insisted to Dr. Richardson weeks ago. Though it had not killed Mr. Haines, cross-contamination still might explain Mrs. Lundgren's death.

Epidemiologists were still confused. How could anthrax that had merely settled on a safe envelope suddenly get back into the air so it could be inhaled, causing the more serious form of the disease? That spores could become airborne again in the whirring tumult of a mail-sorting machine now seemed perfectly reasonable, but on a kitchen table? The answer had been found when they went through Mrs. Lundgren's trash -- clue-hunting of the sort Dr. Snow himself would smile on.

Mrs. Lundgren, it turns out, was quite particular about her mail. Again and again, she tore her letters precisely in half before throwing them in the trash, an act that could easily send any dust or anthrax spores flying back into the air.

The epidemiologists still did not know if in fact a cross-contaminated anthrax letter had arrived in Mrs. Lundgren's mailbox, and for all that they had learned, they didn't know whether, in the end, tearing such a letter in half had actually made a difference. But by then the idiosyncrasies of a little old lady seemed to be all they had to go on.

"In science, we keep the door open for everything," Dr. Garcia said then, two months and counting into the nation's anthrax inquiry.