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 they 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 could 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 night 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 Turkei, 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 late, 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 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 this 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, I am a field person. My wife and I don’t have children. I’m not the kind of a guy who can console a mother, plus I work in 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? 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 seems 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 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.