The Hot Zone

by Richard Preston

  The boy swelled up, and his skin filled with pockets of blood. In some places, the skin almost separated from the underlying tissue. This happened during the last phase, while he was on the respirator. It is called third spacing. If you bleed into the first space, you bleed into your lungs. If you bleed into the second space, you bleed into your stomach and intestines. If you bleed into the third space, you bleed into the space between the skin and the flesh. The skin puffs up and separates from the flesh like a bag. Peter Cardinal had bled out under his skin.

  The more one contemplates the hot viruses, the less they look like parasites and the more they begin to look like predators. It is a characteristic of a predator to become invisible to its prey during the quiet and sometimes lengthy stalk that precedes an explosive attack. The savanna grass ripples on the plains, and the only sound in the air is the sound of African doves calling from acacia trees, a pulse that goes on through the heat of the day and never slows and never ends. In the distance, in the flickering heat, in the immense distance, a herd of zebras graze. Suddenly from the grass comes a streak of movement, and a lion is among them and hangs on a zebra’s throat. The zebra gives out a barking cry, choked off, and the two interlocked beings, the predator and the prey, spin around in a dance, until you lose sight of the action in a billow of dust, and the next day the bones have a surface of flies. Some of the predators that feed on humans have lived on the earth for a long time, far longer than the human race, and their origins go back, it seems, almost to the formation of the planet. When a human being is fed upon and consumed by one of them, especially in Africa, the event is telescoped against horizons of space and time, and takes on a feeling of immense antiquity.

  Peter Cardinal’s parents and sister were stunned as they watched him being slowly torn apart by an invisible predator. They could not comprehend his suffering or reach him to give him comfort. As the blood poured into his third space, his eyes remained open and dilated, staring, bloody, deep, dark, and bottomless. They didn’t know if he could see them, and they couldn’t tell what he saw or thought or felt behind the open eyes. The machines hooked up to his scalp were showing flatlines in his brain. There was very little electrical activity in his brain, but now and then the flatlines gave a spooky twitch, as if something continued to struggle inside the boy, some destroyed fragment of his soul.

  They had to make a decision about whether to turn off the respirator. Dr. Silverstein said to them, “We’re much better off not letting him survive, because of brain death.”

  “If they had only brought him in sooner from Mombasa,” the mother said.

  “I’m sorry, but that would not have helped. There was nothing that anyone could have done,” Silverstein replied to her. “He was doomed from the beginning.”

  Working with his hands in the rubber gloves protruding into the cabinets, Gene Johnson took a little bit of the boy’s blood serum and dropped it into flasks that contained living cells from a monkey. If anything lived in Peter Cardinal’s blood, it might begin to replicate in the monkey cells. Then Johnson went home to get some sleep. The procedure had taken him until three o’clock in the morning to finish.

  In the following days, Johnson watched the flasks to see if there were any changes in the monkey cells. He saw that they were bursting and dying. They were infected with something. The Cardinal strain was definitely a hot agent—it killed the cells in vast numbers, and it killed them fast.

  Now for the next stage of the virus isolation. He drew off a little bit of fluid from the flasks and injected it into three rhesus monkeys, to infect them with the Cardinal agent. Two of the monkeys died and the third animal went into borderline shock, but somehow pulled through and survived. So the Cardinal agent was viciously hot, a fast replicator, and it could kill monkeys. “I knew god-damned well we had Marburg,” Johnson would later say to me.

  He took some of the Cardinal strain and injected it into guinea pigs to see if it would infect them. It killed them like flies. Not only that, the testicles of the males swelled up to the size of golf balls and turned purple. The Cardinal strain was a sophisticated organism that knew what it wanted. It could multiply in many different kinds of meat. It was an invasive life form, devastating and promiscuous. It showed a kind of obscenity you see only in nature, an obscenity so extreme that it dissolves imperceptibly into beauty. It made a living somewhere in Africa. What made it particularly interesting was that it multiplied easily in various species, in monkeys, humans, guinea pigs. It was extremely lethal in these species, which meant that its original host was probably not monkeys, humans, or guinea pigs but some other animal or insect that it did not kill. A virus does not generally kill its natural host. The Marburg virus was a traveler: it could jump species; it could break through the lines that separate one species from another, and when it jumped into another species, it had a potential to devastate the species. It did not know boundaries. It did not know what humans are; or perhaps you could say that it knew only too well what humans are: it knew that humans are meat.

  As soon as he isolated the Cardinal strain and confirmed that it was Marburg, Johnson turned his attention to the question of where and how Peter Cardinal might have become infected. Where had that kid been? What had he been doing to get himself infected? Exactly where had he traveled? These questions haunted Johnson. He had been trying to find the secret reservoirs of the thread viruses for years.

  He telephoned a friend and colleague in Kenya named Dr. Peter Tukei, who was a scientist at the Kenya Medical Research Institute in Nairobi. “We know this is Marburg,” Gene said to him. “Can you get a history of the kid? Find out where he was and what he did?”

  Dr. Tukei said he would locate the parents and interview them.

  A week later, Gene’s telephone rang. It was Dr. Tukei on the line. “You know where that kid was?” he said. “He was in Kitum Cave on Mount Elgon.”

  Gene felt a prickling sensation on his scalp. The paths of Charles Monet and Peter Cardinal had crossed at only one place on earth, and that was inside Kitum Cave. What had they done in the cave? What had they found in there? What had they touched? What had they breathed? What lived in Kitum Cave?

  GOING DEEP

  Eugene Johnson sat at a picnic table at Fort Detrick, near a duck pond, leaning forward and gazing at me. It was a hot day in the middle of summer. He was wearing sunglasses. He placed his large elbows on the table, took off his sunglasses, and rubbed his eyes. He was six foot two, maybe two hundred and fifty pounds. His eyes were brown and set deep in his bearded face, and there were dark circles under the lower lids. He looked tired.

  “So Peter Tukei got on the phone to tell me that the boy had visited Kitum Cave,” Johnson said. “I still get chills when I think about it. A few weeks later, I flew to Nairobi, and I talked with David Silverstein, the kid’s doctor. Peter Tukei was with me. Then we went everyplace in Kenya the kid went, even to his house. His parents had a nice house in Kisumu. Near Lake Victoria. It was a stucco house with a wall around it, and there was a cook and groundskeepers and a driver. The house was clean and neat, open and whitewashed. We saw that there was a rock hyrax living on the roof. It was a pet, and it lived in the gutters. There were a couple of storks, and there were rabbits and goats and all kinds of birds. I didn’t see any bats around the house.”

  He paused, thinking. No one else was around. A few ducks swam in the pond. “I was really nervous about talking with the parents,” he said. “See, my wife and I don’t have children. I’m not the kind of a guy who can console a mother, plus I work for the U.S. military. I had no idea how to talk to them. I tried to put myself in their place, and I remembered how I felt when my father died. I let them talk about their son. Peter Cardinal and his sister had been inseparable from the moment he arrived in Kenya. The kids had spent the whole time together, doing everything together. So what was the difference in behavior? Why did Peter Cardinal get the virus but not his sister? I learned there was one difference in their behavior. The parents told me a
story about the rocks in the cave. They told me their kid was an amateur geologist. There was this issue: did he cut his hand on any crystals in the cave? We went over that possibility with the parents. Peter had said to them that he wanted to collect some of the crystals in Kitum Cave. So he beat on the walls of the cave with a hammer and collected some rocks with crystals in them. The rocks were broken up by the driver and washed by the cook. We tested their blood, and they were not positive for Marburg.”

  It seemed possible that the point of contact had been the boy’s hands, that the virus had entered Cardinal’s bloodstream through a tiny cut. Possibly he had pricked his finger on a crystal that had been contaminated with urine from some animal or the remains of a crushed insect. But even if he had pricked his finger on a crystal, that didn’t tell where the virus lived in nature; it didn’t identify the virus’s natural host.

  “We went to look at the cave,” he said. “We had to protect ourselves when we went inside. We knew that Marburg is transmitted by the aerosol route.”

  In 1986—the year before Peter Cardinal died—Gene Johnson had done an experiment that showed that Marburg and Ebola can indeed travel through the air. He infected monkeys with Marburg and Ebola by letting them breathe it into their lungs, and he discovered that a very small dose of airborne Marburg or Ebola could start an explosive infection in a monkey. Therefore, Johnson wanted the members of the expedition to wear breathing apparatus inside the cave.

  “I brought with me these military gas masks with filters. We needed some kind of covering to put over our heads, too, or we’d get bat shit in our hair. We bought pillowcases at a local store. They were white, with big flowers. So the first time we went into the cave, it was a bunch of Kenyans and me wearing these military gas masks and these flowered pillowcases on our heads, and the Kenyans are just cracking up.”

  They explored the cave and made a map of it. After this scouting trip, Gene Johnson persuaded the Army to sponsor a major expedition to Kitum Cave. Half a year after Peter Cardinal died, in the spring of 1988, Gene showed up in Nairobi with twenty shipping crates full of biohazard gear and scientific equipment. It included several military body bags, for holding human cadavers, and the members of his team had a serious discussion among themselves about how to handle their own remains if one of them died of Marburg. This time, Gene felt that he was closing in on the virus. He knew it would be hard to find even if it lived inside Kitum Cave, but he felt he was getting too close to fail in his quest. The monster lived in a cave, and he was going in there to find it.

  The Kenyan government agreed to close Kitum Cave to tourists while the joint Kenya-U.S. expedition searched it for viruses. The head of the expedition was Dr. Peter Tukei of the Kenya Medical Research Institute. Gene Johnson conceived the idea and gathered the equipment and found the money to pay for it. There were thirty-five team members, and most of them were Kenyans, including wildlife naturalists, scientists, doctors, and laborers. They brought along a large number of guinea pigs, traveling in boxes, and seventeen monkeys in cages, including baboons, Sykes’ monkeys, and African green monkeys. The monkeys and guinea pigs were sentinel animals, like canaries in a coal mine: they would be placed in cages inside and near Kitum Cave in the hope that some of them would break with Marburg virus. There are no instruments that can detect a virus. The best way to find a virus in the wild, at the present time, is to place a sentinel animal at the suspected location of the virus and hope the animal gets sick. Johnson figured that if any of his monkeys or guinea pigs crashed, he would be able to isolate the virus from the sick animals and would perhaps be able to discover how the animals had caught it.

  1988 SPRING

  The Kitum Cave expedition set up headquarters in the Mount Elgon Lodge, a decayed resort dating from the nineteen twenties, when the English had ruled East Africa. The lodge had been built for sporting people and trout fishermen. It sat on a promontory overlooking the red-dirt road that wound up the mountain to Kitum Cave. It had once been surrounded by English gardens, which had partly collapsed into clay and African weeds. Indoors there were hardwood floors, waxed daily to a perfect gleam. The lodge had turrets with round rooms and medieval doors, hand-carved from African olive wood, and the living room boasted an immense fireplace with a carved mantelpiece. The staff spoke very little English, but they were intent on maintaining English hospitality for the rare guest who might happen to show up. The Mount Elgon Lodge was a monument to the incomplete failure of the British Empire, which carried on automatically, like an uncontrollable tic, in the provincial backwaters of Africa long after it had died at the core. In the evenings, as the frost-tinged night came on, the staff built fires of Elgon olive logs in the fireplaces, and the food in the dining room was horrible, in the best English tradition. There was, however, a splendid bar. It was a quaint hideaway in a round chamber, stocked with shining rows of Tusker-beer bottles and French aperitifs and obscure African brandies. The men could sit at the bar and drink Tuskers or lean on the great mantel by the fire and tell stories after a hard day in the cave wearing a space suit. A sign on the wall by the concierge’s desk mentioned the delicate matter of money. It announced that since the Mount Elgon Lodge’s suppliers had cut off all credit to the lodge, the lodge was unfortunately unable to extend any credit to its guests.

  They moved the animals up the mountain in stages, to let them get used to the climate. When they got to the valley that leads to the cave, they cleared away some underbrush and put up blue tarpaulins. The cave itself was considered to be a Level 4 hot zone. The tarp closest to the cave covered a gray area, a place where the worlds met. The men took chemical showers under the gray-area tarp, to decon their space suits after a visit to the cave. Another tarp covered a Level 3 staging area, where the men changed in and out of their space suits. Another tarp covered a Level 4 necropsy area. Under that tarp, wearing space suits, they dissected any small animals they had trapped, looking for signs of Marburg virus.

  “We were going where no one had gone before,” Johnson said to me. “We brought the Biosafety Level 4 philosophy to the jungle.”

  They wore orange Racal space suits inside the cave. A Racal suit is a portable, positive-pressure space suit with a battery-powered air supply. It is for use in fieldwork with extreme biohazards that are believed to be airborne. A Racal suit is also known as an orange suit because it is bright orange. It is lighter than a Chemturion, and unlike a Chemturion, it is fully portable, with a self-contained breathing apparatus. The main body of the suit (apart from the helmet and the blowers) is disposable, so that you can burn it after using it once or twice.

  Wearing their Racal space suits, they laid out a trail that wound into Kitum Cave, marking the trail with avalanche poles so that people would not get lost. Along the trail, they placed cages holding the monkeys and guinea pigs. They surrounded the cages with electrified wire, powered by a battery, to discourage leopards from trying to eat the monkeys. They placed some of the monkeys directly underneath bat colonies in the roof of the cave, hoping that something would drop on a monkey that would cause the animal to break with Marburg.

  They collected somewhere between thirty thousand and seventy thousand biting insects inside the cave—the cave is full of bugs. “We put stickum paper over cracks in the cave, to catch crawling bugs,” Johnson said to me. “We hung light traps inside the cave to collect flying insects. The light traps were battery powered. You know how to collect ticks? They come out of the ground when they smell carbon dioxide from your breath. They smell it and come up and bite your ass. So we brought these huge tanks of carbon dioxide, and we used it to attract ticks. We trapped all the rodents that went into the cave. We used Havahart traps. Way at the back of the cave, by a pool of water, we found sand flies. These are biting flies. We saw leopard tracks all over the place, and Cape-buffalo tracks. We didn’t take any blood samples from large animals, nothing from leopards or buffalo. Nothing from the antelopes.”

  “Could Marburg live in large African cats?” I
asked. “Could it be a leopard virus?”

  “Maybe. We just didn’t have permits to trap leopards. We did collect genet cats, and it wasn’t there.”

  “Could it live in elephants?”

  “Did you ever try to draw blood from a wild elephant? We didn’t.”

  The Kenyan naturalists trapped and netted hundreds of birds, rodents, hyraxes, and bats. In the hot necropsy zone, under the tarp, they sacrificed the animals and dissected them while wearing Racal suits, taking samples of blood and tissue, which they froze in jars of liquid nitrogen. Some local people—they were Elgon Masai—had lived inside some of the caves on Mount Elgon and had kept their cattle in the caves. The Kenyan doctors drew blood from these people and took their medical histories, and drew blood from their cattle. None of the local people or the cattle tested positive for Marburg antibodies—if they had tested positive, it would have shown that they had been exposed to Marburg. Despite the fact that nobody showed signs of having been infected, the Elgon Masai could tell stories of how a family member, a child or a young wife, had died bleeding in someone’s arms. They had seen family members crash and bleed out, but whether their illnesses were caused by Marburg or some other virus—who could tell? Perhaps the local Masai people knew the Marburg agent in their own way. If so, they had never given it a name.