The Blue Death

by Dr. Robert D. Morris

  The call from Kathy Blair and Steve Gradus requesting water quality data from both plants left the staff at each puzzled. Why would anyone want data when the water was meeting standards? This was such an unusual request that there was some confusion as to how to provide the data. The staff at the Howard Avenue plant, however, was more than confused; they were reluctant to provide any data.

  Blair and Gradus persisted. Their query led them up the chain of command until they spoke with Jim Wagner, the manager of the city’s two water treatment plants. Like everyone else they talked to, Wagner told them to forget about drinking water in their search for a cause. An engineer from the old school, Wagner seemed to see their request as a meddlesome annoyance. All measures of water quality, he assured them, had been well within the EPA’s standards. Getting the data would require that he slog through handwritten logbooks kept at each plant. Nonetheless, he promised he would get the water-quality data to them the following morning.

  By Monday afternoon local news reporters had caught the scent of the developing story. One newspaper reporter asked Kathy Blair about the rumor that this was a waterborne outbreak. Based on what she had heard from the staff at the treatment plants, she assured him that the water supply could not in any way be linked to the outbreak.

  As the Milwaukee media prepared to file their first stories on the outbreak, three pieces of the puzzle had already fallen into the lap of Dr. Jeff Davis, Chief Medical Officer at the Wisconsin State Department of Public Health in Madison. Everything about Davis’s background, it seemed, had prepared him for this moment. Not only was he a specialist in infectious diseases, but he had also trained as an epidemiologist at the federal Centers for Disease Control and Prevention (CDC) in Atlanta. For fifteen years he had directed the investigation of every significant outbreak of infectious disease in Wisconsin as the state’s top epidemiologist for communicable diseases. Now he had a mystery to solve in his home town.

  Davis knew that Milwaukee was experiencing an outbreak of gastroenteritis large enough to strip local pharmacies of over-the-counter medications and to close schools and businesses. He also knew that the disease could be severe. It had sent so many people to the hospital that at least one lab had run out of supplies for bacterial cultures. Finally he knew that the standard laboratory studies had come up empty.

  So Davis knew he was looking at a massive explosion of gastrointestinal disease. The pathogen, whatever it was, could cause serious, even life-threatening, illness and did not appear to be bacterial. He sorted through the same set of alternatives as the public health workers in Milwaukee. The pathogen could be spreading by any of four pathways: personal contact, food, air, or water. If it was spreading from person to person, it was more virulent than anything he had ever seen before. Even a fast-moving virus creates a series of small explosions as it hits one classroom or workplace after another. This was a nuclear blast. Not only had it had grown too fast to be spread by personal contact, it had also grown too big to be a typical foodborne outbreak. Airborne outbreaks could be large and spread rapidly, but there was little sign of respiratory disease among those in the hospital. Waterborne outbreaks always involved a major breakdown in the water treatment process. The water in Milwaukee had not violated federal standards and, as far as he knew, nothing was wrong with the plant. Furthermore no major American city had seen a significant outbreak of waterborne disease since the widespread adoption of routine modern filtration and chlorination systems more than seventy years earlier. Nothing seemed to fit.

  Nothing, that is, if the infectious agent had come from the universe of the familiar. Davis’s years of experience with infectious diseases had taught him all too well that pathogens have a remarkable ability to change their stripes. This could be a familiar pathogen acting in an unfamiliar way. More alarming was the possibility that this was a new or emerging human pathogen, an agent that had never before shown itself or only recently shown itself to be capable of causing disease in humans. As he considered these disturbing scenarios, a third possibility dawned on him. Perhaps this was a somewhat unfamiliar pathogen acting in a somewhat unfamiliar way. If so Jeff Davis had a suspect.

  11

  THE HIDDEN SEED

  B y the time Paul Nannis, Milwaukee’s Health Commissioner, picked up the morning paper on Tuesday, April 6, the outbreak lay sprawled across the front page. Four more Catholic schools were closed on Milwaukee’s south side. At the Milwaukee County Medical Complex, physicians who only saw sporadic cases of severe vomiting or diarrhea on a typical day now found that half their patients had some sort of gastrointestinal illness.

  One of those patients was Mark Rahn, the car salesman from Chicago. Just three days after emerging from the hospital having survived a bone marrow transplant, Rahn could no longer eat. The mere scent of food made him vomit. He couldn’t even hold down a glass of water. At the same time, the intense diarrhea was draining twelve quarts of fluid a day from his body. Doctors were pouring saline into his veins in an effort to keep ahead of dehydration. The saline, however, was not enough.. Unable to absorb food, he began to decline. To stave off malnutrition, his doctors would soon need to insert a tube into the large veins in his chest and begin total parenteral nutrition (TPN). For the next ten weeks, they would pump food into his blood as his crippled immune system struggled with the invader. The fight against cancer is not a single battle, but a protracted war. He had been ambushed and was fighting for his life.

  As Mark Rahn lay in isolation at Milwaukee County Hospital, Steve Gradus, the director of the lab at the Milwaukee Health Department, sat at his desk reviewing the water-quality records from the water treatment plants. Most of the data looked unremarkable. The records showed that there had been bacteria in the water from Lake Michigan, but that was to be expected. Both plants had added plenty of chlorine. There had even been bacteria in the treated water, but the levels had been low and well within federal limits. In fact, the plant had met all water quality standards throughout the period leading up to the outbreak. Then something caught his eye.

  Gradus went down to the first floor to show the data to Kathy Blair, the city epidemiologist. As they looked them over, the phone rang. It was Jeff Davis, the state infectious disease epidemiologist. When Davis learned what Gradus had found, he told him that he would arrive from Madison the following morning. He would come with a team of scientists from the State Department of Public Health. Davis was growing convinced that this was a waterborne outbreak and began to believe he knew the cause.

  What Gradus saw in the data was the trace of a series of events that had their beginnings weeks before as Wisconsin thawed and water filled its every pore. In the spring of 1993, like so many springs before it, rain and snowmelt had seeped from the soggy farms, forests, and towns along the rivers that feed Lake Michigan. An ideal solvent drawn inexorably toward the sea, the cold runoff rinsed the landscape of southeastern Wisconsin. By the time the water found its course, it swirled with everything from road salt and rotting leaves to pesticides and cow manure. As the Milwaukee surged toward the lake, fourteen sewage treatment plants and almost a thousand industries poured their wastewater into the river.

  The waters of Lake Michigan had spent the bitter cold winter locked in layers. Particles that fell through the icy depths had spent the season trapped on the lake bottom. The slow spring warming altered the density of the layers of water and stirred this elaborate limnological cocktail. The annual mixing sent clouds of detritus surging toward the surface for the first time since the fall. As the river, swollen with snowmelt, crashed into the lake, the water boiled with nutrients, mud, and microbes.

  The churning water reached out into the lake farther and farther until it found the mouth of a massive pipe. That pipe stretched back to the shore, crawling along the lake bottom for more than a mile before rising from the water, piercing a high bluff, and tunneling beneath the suburban streets to its origin in the pump room of the Howard Avenue Water Treatment Plant. The lake water that surrounded the ja
ws of the pipe swarmed with an infinity of particles. The huge bank of pumps with the capacity to pull more than 100 million gallons of water into the plant each day sucked up these particles like a massive vacuum cleaner.

  On that day the chemist at the Howard Avenue Treatment Plant was peering into six glass jars of frigid Lake Michigan water. Spring runoff loaded with particles was nothing new for him. He had seen it happen every spring. Controlling this turbidity had always been a routine matter. Unfortunately nothing was routine for Milwaukee’s water in the early spring of 1993.

  The cloudiness of the water flowing from the plant to the faucets and bubblers of Milwaukee had jumped sharply during the day. The chemist expected to see high turbidity in the water entering the plant in the spring. Even the turbidity of the treated water might be higher than usual, but when he had measured the turbidity of the water leaving the plant earlier that day, it was more than twenty times the level he had measured just one week earlier. The plant operators, it seemed, had a problem.

  One of the jars on the lab bench should hold the answer to their problem. The chemist had added a different amount of coagulant to each of the six jars. The chemical coagulant would cause fine particles to clump together so that the sand filters could remove them. After the particles had settled, he picked the jar with the water that appeared clearest and recorded the concentration of coagulant in that jar. He then walked downstairs to the operations room of the plant and wrote a chemical change order in the logbook. Soon the chemical technician would check the logbook and adjust the chemical feed pumps so that the concentration of coagulant in the plant matched the coagulant in the jar.

  The adjustments to the coagulant dose usually brought the turbidity down. To be sure the chemist took a water sample and placed it in the laboratory’s turbidimeter. When he read the meter, he was surprised to discover that the turbidity had not dropped. It had gone up. It would continue to rise over the next forty-eight hours and would stay elevated for five days. This was the spike that Steve Gradus would see as the outbreak took shape.

  During those five days, the manager of the water treatment plants, James Wagner, carefully followed the data coming out of the plant’s laboratory. In addition to turbidity, laboratory technicians tested samples for the presence of bacteria and for levels of chlorine many times each day. The turbidity, to his mind, was higher than he would have liked, but below federal limits. More important the treated water had tested negative for bacteria. This indicated that so few bacteria had survived the treatment process that there was little chance they could cause any illness. The plant, like almost every other treatment plant in the country, relied on chlorine to inactivate any pathogens that might have squeezed through its filters. Wagner made certain they were adding plenty of chlorine to the water.

  Wagner still had reason to believe the water was safe. It had not violated federal standards. But something bothered him. As the turbidity continued to defy their efforts to fully control it, he placed a call to Paul Biedrzycki, head of the environmental health division at the health department.

  “Where’s the flu?” Wagner asked without preamble or explanation. The question landed like a carp falling from a clear blue sky.

  “Huh,” said Biedrzycki. Not only had Wagner offered no explanation for his question, but influenza normally strikes during the winter, not the spring.

  “The flu, what area of town is the flu?” Wagner offered, already at the limit of his willingness to explain the question.

  Puzzled, Biedrzycki suggested he call the virologist Gerry Sedmak. Then, as abruptly as he had started the conversation, Wagner hung up. Biedrzycki could only wonder what had prompted the call. He set down the receiver and moved on to the other environmental health issues that concerned Milwaukee. Up to that moment, drinking water had been a minor part of his job. He didn’t give the call much more thought until weeks later, when he realized that he had heard the first whisper of an outbreak.

  As the mysterious outbreak gripped the city, the laboratory at Milwaukee’s health department began to receive stool samples from hospitals around Milwaukee. Steve Gradus hoped he would find the key to unraveling the mystery of this outbreak hidden in these samples. Portions would be tested for bacteria and viruses, both in the city lab and at the CDC laboratory in Atlanta. These were the most likely suspects, but Gradus had to consider all the possibilities.

  Protozoa, intestinal worms, and other parasites could also infect the human gut. Many of these agents could be found with nothing more than a microscope and a keen eye. Dr. Ajaib Singh and his staff in the microbiology laboratory had been combing through the samples, but had yet to find a single egg, worm, or oocyst. The lab had more sensitive tests for protozoa, but those would take time. Since the preliminary results of the bacterial cultures also were negative, Gradus still had nothing solid to work with. He had to assume for the moment that the viral studies, still pending, would reveal the culprit.

  In the conference room, the battle lines were drawn. On one side were the experts and administrators from the DPW. They had two labs devoted to nothing but testing drinking water quality and a fleet of engineers, chemists, and microbiologists trained and experienced in the treatment of drinking water. On top of that, they had the authority of the federal government whose experts who had set the standards for drinking water, standards that had all been followed during the week before the outbreak. If the battle became political, Jim Kaminski, director of the DPW, would take over. In the jungle of politics, Kaminski was an anaconda.

  The health department, represented by Paul Nannis, Steve Gradus, Kathy Blair, and Tom Schlenker, had little expertise in drinking water. Even Paul Biedrzycki, the person in the health department assigned to drinking water, had no firsthand experience in the treatment of drinking water or the investigation of a waterborne disease outbreak. Furthermore, he was not at the meeting. Nonetheless, they knew enough to ask the team from the waterworks about the rise in turbidity that Steve Gradus had noticed in their records. In response the team from the waterworks pointed out that there was plenty of chlorine in the water and federal standards had not been violated. Drinking water could not have caused the outbreak.

  As Gradus pressed his point, describing a waterborne outbreak that had occurred seven years earlier in Carrollton, Georgia, the meeting began to heat up. Gradus pointed out that a rise in turbidity had preceded that outbreak, but the notion that Milwaukee’s massive treatment plants, with their small army of experts, might have the same problems that had plagued some obscure city in Georgia tried the patience of the DPW staff. The water simply could not have caused the outbreak. There had been plenty of chlorine in the water. The bacterial counts had been within federal limits. The turbidity levels not only met standards, they were, in his mind, irrelevant.

  Tempers flared in a gathering storm of indignation. From the perspective of the DPW staff, a nurse, a microbiologist, a physician, and a social worker were lecturing the waterworks about drinking water. Not only did none of them have any engineering training or experience, they had probably never set foot inside a treatment plant. Then the storm broke. One DPW senior staff member began to pound on the table as he explained that turbidity had nothing to do with pathogens in the water. Turbidity in the water was simply an aesthetic quality, no more, no less. He continued to pound on the table as he spoke, as if the sheer force of his conviction would make it so.

  In the end the staff at the health department, despite their belief that this looked like a waterborne outbreak, could not dismiss the DPW’s conclusions. An epidemiological hunch could not trump the expertise and experience of the staff at the water treatment plant. According to federal experts at the EPA, the water had been safe. No one had found a pathogen that could be waterborne. This superficial resemblance to an outbreak in a college town in Georgia was simply not compelling. So that evening when reporters asked Paul Nannis if water could be responsible for the outbreak, he told them that Milwaukee’s water is tested daily and “looks fin
e.”

  By late in the day on Tuesday, April 6, faxes began to arrive at the health department from hospital laboratories around the city. Final culture results had confirmed preliminary findings. There was no sign of a major bacterial pathogen. If indeed bacteria were not responsible for the outbreak, viruses became prime suspects. It would take several days to get results from the viral cultures now running at the CDC and in the health department’s own labs.

  The staff at the health department continued to work late into the night on Tuesday, hoping for a break in the case. Until they got a clear finding from the microbiology lab, epidemiology was their best hope for some answers. The scope of the outbreak, however, was beyond anything they had ever attempted to investigate.

  The next morning brought a growing sense of urgency together with some much needed help. At nine o’clock Jeff Davis and a team of epidemiologists from the State Department of Public Health arrived to join in the hunt. Phones and computers were brought in to a second floor conference room that would come to be known as the war room. Working closely with the health department staff, Davis and his team began to map out a series of studies that would help to define what was happening in Milwaukee.

  With thick brown hair, a serious air, and the mustache that, in 1993, communicated a lingering connection to the sixties, Davis had a depth of experience and training concerning infectious disease outbreaks that far outstripped anyone else in the room. He began, however, with the basics. Every epidemiologist is taught to begin an outbreak investigation with the four Ws. What is the disease? Who is being afflicted? Where do they live, work, and go to school? When did they fall ill?