All in Good Haste
HANTAVIRUSES IN AMERICA
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Neither rat nor man has achieved social, commercial, or economic stability. This has been, either perfectly or to some extent, achieved by ants and by bees, by some birds, and by some of the fishes in the sea. Man and the rats are merely, so far, the most successful animals of prey. They are utterly destructive of other forms of life. Neither of them is of the slightest use to any other species of living things.
âHans Zinsser,
Rats, Lice
,
and History
, 1934
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Long-distance runner Merrill Bahe was on his way to his girlfriend's funeral on May 14, 1993, when he found himself gasping for air. Suddenly, and quite dramatically, Bahe was overcome with fever, headache, and respiratory distress. In the presence of his grief-stricken relatives, Bahe gulped desperately for air in their car, en route south to Gallup, New Mexico.
Minutes later the nineteen-year-old Navajo athlete was dead.
His twenty-four-year-old girlfriend had died in a small Indian Health Service clinic located sixty miles away from Gallup a few days earlier after an identical bout of sudden respiratory illness. And within the week her brother and his girlfriend, also young, athletic Navajos, who lived in trailers near Bahe's, fell mysteriously ill; the young woman died.
Word spread across the Navajo Nation of 175,000 people, living in an area of seventeen million acres spanning four statesâArizona, New Mexico, Colorado, and Utah. Because the borders of the four states met in the area, the region was called Four Corners. The locale for many John Wayne Westerns, Four Corners was surrounded by massive tracts of sparsely populated sandstone landscape that plunged into majestic canyons and arched upward forming dramatic ridges and peaks. It was a place where people spoke of “big sky” as they gazed across the psychedelically colored desert to the wide expanse that reached to the horizon.
The entire Navajo Nation was soon buzzing with the news of three strong, young members of the community who suddenly found themselves gasping in vain for air.
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Before Merrill Bahe was carried into the emergency room of the Indian Health Center in Gallup, resuscitation attempts in the ambulance had
failed. Bahe was declared DOA, dead on arrival. His death shocked the already bereaved families and sent a chill through the medical staff.
Attending IHS internist Bruce Tempest was struck by Bahe's youth and athleticism, and he recalled discussing a similar case over the phone with an IHS colleague at another Navajo clinic. When he realized that the other case was Bahe's fiancée, Tempest took three decisive steps that eventually cast Bahe's death in the light of a national epidemic investigation, rather than a mere routine case of unexplained illness.
First, he called the state medical examiner, alerting the forensic pathologist to the possibility of a communicable disease problem. The New Mexico examiner, Richard Malore, immediately declared jurisdiction, placing Bahe's body under an autopsy order. Then the investigator walked across the street and similarly took custody of Bahe's fiancée's corpse.
While pathologists prepared the bodies for full autopsies that would keep them working around the clock over the May 14 weekend, Tempest took his second decisive step, reaching again for the telephone. The Navajo IHS was unique in that its clinics were spread out over an area so vast that some physicians never had an opportunity to meet one another. But they were in constant telecommunication, and IHS physicians known for their particular expertise received dozens of calls a day from other doctors working in American Indian clinics from Colorado all the way down to Window Rock, Arizona, hundreds of miles to the south.
Tempest, who had worked in the area for the IHS since 1967, was known for his unique problem-solving facility in confusing situations. As a result, he already had on his desk in Gallup the medical files on a Navajo woman who had died mysteriously in a distant clinic around Christmastime of an apparently similar acute respiratory distress, and he had served as a telephone adviser on a couple of other puzzling pulmonary cases during the spring.
Now he got on the horn and called all those attending physicians, asking for details on the earlier respiratory death cases.
“So by the end of the day, Friday [May 14], I was able to compile a list of five healthy young people who had died of acute respiratory distress syndrome,” Tempest later said.
He called in the New Mexico Department of Health and IHS epidemiologist Dr. Jim Cheek. The state set its laboratories in motion, testing the autopsy samples and reviewing medical charts, looking for evidence of respiratory diseases that had haunted the Navajos for decades: bubonic plague,
Hemophilus
influenza, viral pneumonia, and influenza.
The obvious and immediate autopsy finding was that the lungs of Bahe and his girlfriend were so severely fluid-filled that they weighed twice as much as would normally be expected for young adults of their sizes.
If Tempest or someone else in Four Corners hadn't spotted the cases and sent alerts immediately in the proper directions, the mini-epidemic would have gone unnoticed, according to sources at all levels. Tempest
never hesitated, however. Nor did his counterparts in the New Mexico Health Department.
By May 16, the state medical examiner and the labs were unable to find evidence of flu, or any other common viruses or bacteria, in the autopsied materials. On Wednesday, May 19, when Tempest alerted Jim Cheek, the IHS chief epidemiologist had already heard rumors of “weird deaths” in the northeastern part of the Navajo Nation from a Navajo co-worker in his office. Cheek hadn't paid them much attention at the time. New Mexico state epidemiologist C. Mack Sewell told Cheek the initial conclusion was that the first couple had died of pneumonic plague.
Isolated cases of the bubonic form of the plague had occurred sporadically among the Navajos for decades, carried by wild prairie dogs. Since the early 1970s, when Jonathan Mann ran the New Mexico epidemiology program, the state had maintained a strong and vigilant plague surveillance program, quickly spotting the occasional case. Far less common was pneumonic plague, in which the bacteria grew in the victims' lungs and could be spread through the air from one person to another.
New Mexico had an extraordinary plague laboratoryâpossibly the best in the worldâand the state had seen enough cases over the years to be able to rapidly diagnose and stop an outbreak. On the basis of their symptoms, state health officials therefore hypothesized that Bahe and his girlfriend had died of pneumonic plague.
But that wasn't what the laboratory concluded. No plague bacteria could be found in the victims' blood or tissue samples.
Cheek set his small IHS team into action, immediately exploring three avenues: hospital records on other recent unexplained respiratory deaths in the area, a computer search on chemicals known to cause such symptoms, and an investigation of the Bahe home and community.
ARDS, or acute respiratory distress syndrome, was typically the final cause of death of millions of people worldwide every year. Most cases, 50 to 90 percent, occurred in elderly people, burn patients, victims of traumatic injuries, or other individuals for whom a clear cause of the rapid lung fluid buildup was evident. But in a minority of cases, no obvious basis for the respiratory distress could be found, and doctors usually listed cause of death as “ARDS of unknown etiology.”
Cheek's team scoured IHS medical records for the spring of 1993 looking for unknown etiology ARDS cases. Five popped upâoverlapping with Tempest's listâand Cheek had them investigated.
Meanwhile, Cheek suspected a toxic chemical as the culprit for the first two cases. A computer search turned up several possibilities, but “the one that fit the bill perfectly,” Cheek said, was phosgene. Used during World War I by the Germans, phosgene could cause symptoms of ARDS over twenty-four hours after exposure. A sister compound, phosphene, produced more rapid symptoms, but was also known to cause ARDS. After snooping around a bit, disease detective Cheek learned that phosgene had long been
banned in the United States and it would be exceedingly difficult to produce toxic levels of the chemical through such practices as arc welding, which could create trace amounts of the compound.
But phosphene, he discovered, was legally used to kill prairie dogs. Over the winter CDC scientists working out of the agency's laboratory in Fort Collins, Colorado, had predicted that record snowfalls in the 1992â93 season in the Four Corners region would result in an increase in the springtime prairie dog population. And with that, the scientists forecast, would come increased plague. As it turned out, the region was inundated with record levels of snowfall. Putting the phosphene pieces of the puzzle together, Cheek thought, “Aha! We have something here. Somebody has been doing some prairie dog eradication.”
But his enthusiasm was soon dampened by an investigative visit to the Bahe dwelling, a trailer. He found no sign of phosphene containers, chemical spray apparatuses, or residual chemicals. In fact, he found nothing out of the ordinary in the empty trailer, except, perhaps, an unusual amount of mouse feces scattered here and there. Cheek assumed that the rodents had invaded the trailer after it was abandoned by the ailing humans.
While he poked about Bahe's trailer, gathering rodent feces, dishes, clothing, and other articles for laboratory scrutiny, Cheek took no special precautions for his own safety. It hadn't occurred to him that whatever killed the three Navajos might still be present, in a transmissible form. So he wore no respirator mask, no special latex gloves, no protective unit.
Cheek would later marvel about his foolishness and luck.
By May 20, Cheek had a list of ten suspected cases, all from the Four Corners area, and he was stumped. The thirty-five-year-old physician had been in the New Mexico area for only seven months, and he was running out of ideas. So, having spent the previous two years working as a CDC Epidemic Intelligence Service officer, he called the agency's top epidemiologist and his old friend Rob Breimen.
“I wondered if it might be some kind of mycoplasma [bacteria], because they're so hard to culture in the laboratory. I thought maybe that's why we weren't finding anything,” Cheek later said.
Breimen, who had been involved in previous investigations of equally puzzling outbreaks, including Legionnaires' Disease, was intrigued, until he tossed ideas around for a while, sighed, and tried to dismiss the issue as “a small problem.”
But try as he might to focus on the more pressing issues on his Saturday working agenda, Breimen couldn't shake Cheek's intriguing puzzle from his mind, and on Monday, May 24, he phoned Albuquerque for a faxed rundown of the cases.
That same day the New Mexico Department of Health sent letters to all the state's physicians, describing the mysterious disease and requesting immediate notification should other cases be seen.
The next day Breimen shared the curious list of ten suspect ARDS cases
with a few CDC colleagues, all of whom agreed that there was something awfully odd about such sudden deaths among healthy young people.
The following night Breimen was on a four-hour conference call with the New Mexico and Arizona state epidemiologists. The trio went over the details of some nineteen suspected cases found in the two statesânot all of which were among Navajos. Twelve had died. The victims ranged in age from nineteen-year-old Bahe to a fifty-eight-year-old woman. Most had taken ill during the month of May. With the Memorial Day weekend approaching, the three epidemiologists were anxious to figure out whether or not they had a genuine epidemic on their handsâone that might suddenly explode over the federal holiday when most government scientists and physicians were on vacation.
That same Wednesday, the CDC's physician-scientist Louisa Chapman was going over some old chronic fatigue syndrome data when an anonymous caller from the Navajo Nation rang up, requesting urgent advice. Nervous, the man identified himself only as a dentist, and wanted to know if he should close down his office.
“Why would you want to do that?” asked Chapman, a tough scientist whose baby face belied her nearly ten years of experience in infectious disease investigations.