monkeys from 14th-23rd. The first symptoms appeared on August 21st. The laboratory assistant RENATE L. broke a test-tube that was to be sterilized, which had contained infected material, on August 28th, and fell ill on September 4th 1967.
And so on. The victims developed headaches at about day seven after their exposure and went downhill from there, with raging fevers, clotting, spurts of blood, and terminal shock. For a few days in Marburg, doctors in the city thought the world was coming to an end. Thirty one people eventually caught the virus; seven died in pools of blood. The kill rate of Marburg turned out to be about one in four, which makes Marburg an extremely lethal agent: even in the best modern hospitals, where the patients are hooked up to life-support machines, Marburg kills a quarter of the patients who are infected with it. By contrast, yellow fever, which is considered a highly lethal virus, kills only about one in twenty patients once they reach hospital.
Marburg is one of a family of viruses known as the filoviruses. Marburg was the first filovirus to be discovered. The word filovirus is Latin and means “thread virus”. The filoviruses look alike, as if they are sisters, and they resemble no other virus on earth. While most viruses are ball-shaped particles that look like peppercorns, the thread viruses have been compared to strands of tangled rope, to hair, to worms, to snakes. When they appear in a great flooding mess, as they so often do when they have destroyed a victim, they look like a tub of spaghetti that has been dumped on the floor. Marburg particles sometimes roll up into loops. The loops resemble Cheerios. Marburg is the only ring-shaped virus known.
In Germany, the effects of Marburg virus on the train were particularly frightening, and resembled the effects of rabies: the virus somehow damaged the central nervous system and could destroy the brain, as does rabies. The Marburg particles also looked rather like rabies particles. The rabies virus particle is shaped like a bullet. If you stretch out a bullet, it begins to look like a length of rope, and if you coil the rope into a loop, it becomes a ring, like Marburg. Thinking that Marburg might be related to rabies, they called it stretched rabies. Later it became clear that Marburg belongs to its own family.
Not long after Charles Monet died, it was established that the family of filoviruses comprised Marburg along with two types of virus called Ebola. The Ebolas were named Ebola Zaire and Ebola Sudan. Marburg was the mildest of the three filovirus sisters. The worst of them was Ebola Zaire. The kill rate in humans infected with Ebola Zaire is nine out of ten. Ninety percent of the people who come down with Ebola Zaire die of it. Ebola Zaire is a slate wiper in humans.
Marburg virus (the gentle sister) affects humans somewhat like nuclear radiation, damaging virtually all of the tissues in their bodies. It attacks with particular ferocity the internal organs, connective tissue, intestines, and skin. In Germany, all the survivors lost their hair—they went bald or partly bald. Their hair died at the roots and fellout in clumps, as if they had received radiation burns. Hemorrhage occurred from all orifices of the body. I have seen a photograph of one of the men who died of Marburg, taken in the hours before his death. He is lying in bed without any clothing on his upper body. His face is expressionless. His chest, arms, and face are speckled with blotches and bruises, and droplets of blood stand on his nipples.
During the survivors’ recovery period, the skin peeled off their faces, hands, feet, and genitals. Some of the men suffered from blown up, semirotten testicles. One of the worst cases of this appeared in a morgue attendant who had handled Marburg-infected bodies. The virus also lingered in the fluid inside the eyeballs of some victims for many months.
No one knows why Marburg has a special affinity for the testicles and the eyes. One man infected his wife with Marburg through sexual intercourse.
Doctors noticed that the Marburg agent had a strange effect on the brain. “Most of the patients showed a sullen, slight aggressive, or negativistic behavior,” according to the book. “Two patients (had) a feeling as if they were lying on crumbs.” One patient became psychotic, apparently as a result of brain damage. The patient named Hans O.-V. showed no signs of mental derangement, and his fever cooled, and he seemed to be stabilizing, but then suddenly, without warning, he had an acute fall in blood pressure—he was crashing—and he died. They performed an autopsy on him, and when they opened his skull, they found a massive, fatal hemorrhage at the center of the brain. He had bled out into his brain.
International health authorities were urgently concerned to find the exact source of the monkeys, in order to pin down where in nature the Marburg virus lived. It seemed pretty clear that the Marburg virus did not naturally circulate in monkeys, because it killed them so fast it could not successfully establish itself in them as a useful host. Therefore, Marburg lived in some other kind of host—an insect? a rat? a spider? a reptile? Where, exactly, had the monkeys been trapped? That place would be the hiding place of the virus. Soon after the outbreak in Germany, a team of investigators under the auspices of the World Health Organization flew to Uganda. The team couldn’t discover the exact source of the virus.
There the mystery lingered for many years. Then, in 1982, an English veterinarian came forward with new eyewitness information about the Marburg monkeys. I will call this man Mr. Jones (today, he prefers to remain anonymous). During the summer of 1967, when the virus erupted in Germany, Mr. Jones was working at a temporary job inspecting monkeys at the export facility in Entebbe from which the sick Marburg monkeys had been shipped, while regular veterinary inspector was on leave. This monkey house, which was run by a rich monkey trader (“a sort of lovable rogue,” according to Mr. Jones) was exporting about thirteen thousand monkeys a year to Europe. This was a very large number of monkeys, and it generated big money. The infected shipment was loaded onto an overnight flight to London, and from there it was flown to Germany—where the virus broke out of the monkeys and “attempted” to establish itself in the human population.
After making a number of telephone calls, I finally located Mr. Jones in a town in England, where today he is working as a veterinary consultant. He said to me: “All that animals got, before they were shipped off, was a visual inspection.”
“By whom?” I asked.
“By me,” he said. “I inspected them to see that they appeared normal. On occasion, with some of these shipments, one or two animals were injured or had skin leisons.” His method was to pick out the sick-looking ones, which were removed from the shipment and presumably killed before the remaining healthy-looking animals were loaded onto the plane. When, a few weeks later, the monkeys started the outbreak in Germany, Mr. Jones felt terrible. “I was appalled, because I had signed the export certificate,” he said to me. “I feel now that I have the deaths of these people on my hands. But that feeling suggests I could have done something about it. There was no way I could have known.” He is right about that: the virus was then unknown to science, and as few as two or three not-visibly-sick animals could have started the outbreak. One concludes that the man should not be blamed for anything.
The story becomes more disturbing. He went on: “The sick ones were being killed, or so I thought.” But later he learned that they weren’t being killed. The boss of the company was having the sick monkeys put in boxes and shipped out to a small island in Lake Victoria, where they were released. With so many sick monkeys running around it, the island could have become a focus for monkey viruses. It could have been a hot island, an isle of plagues. “Then, if this guy was a bit short of monkeys, he went out to the island and caught a few, unknown to me.” Mr. Jones thinks it is possible that the Marburg agent had established itself on the hot island, and was circulating among the monkeys there, an that some of the monkeys which ended up in Germany had actually come from that island. But when the WHO team came later to investigate, “I was told by my boss to say nothing unless asked.” As it turned out, no one asked Mr. Jones any questions—he says he never met the WHO team. The fact that the team apparently never spoke with him, the monkey inspector, “was bad epidemiology but good politics,” he remarked to me. If it had been revealed that the monkey trader was shipped off suspect monkeys collected on a suspect island, he could have been put out of business, and Uganda would have lost a source of valuable foreign cash.
Shortly after the Marburg outbreak, Mr. Jones recalled a fact that began to seem important to him. Between 1962 and 1965 he had been stationed in eastern Uganda, on the slopes of Mount Elgon, inspecting cattle for disease. At some time during that period, local chiefs told him that the people who lived on the north side of the volcano, along the Greek River, were suffering from a disease that caused bleeding, death, and “a particular skin rash”—and that monkeys in the area were dying of a similar disease. Mr. Jones did not pursue the rumors, and was never able to confirm the nature of the disease. But it seems possible that in the years preceding the outbreak of Marburg virus in Germany, a hidden outbreak of the virus occurred on the slopes of Mount Elgon.
