Read Online Spillover: Animal Infections and the Next Human Pandemic by David Quammen - Free Book Online Page B

are collectively known as ebolaviruses. On a smaller scale, within Gabon alone, there has been a tight clustering of Ebola incidents: three in less than two years, and all three rather closely localized in space. Mayibout 2 was the middle episode of that cluster.
    An earlier outbreak began during December 1994 in the gold-mining camps on the upper Ivindo, the same area from which Mike Fay later recruited his Gabonese crew. These camps lie about twenty-five miles upstream from Mayibout 2. At least thirty-two people got sick, showing the usual range of symptoms (fever, headache, vomiting, diarrhea, and some bleeding) that suggest Ebola virus disease. The source was hard to pinpoint, though one patient told of having killed a chimpanzee that had wandered into his camp and acted strangely. Maybe that animal was infected, inadvertently bringing the contagion to hungry humans. According to another account, the first case was a man who had come across a dead gorilla, took parts of it back to his camp, and shared. He died and so did others who touched the meat. Around the same time came some reports of chimps, as well as gorillas, seen dead in the forest. More generally, the miners (and their families—these camps were essentially villages) by their very presence, their needs for food, shelter, and fuel, had caused disturbance to the forest canopy and the creatures that lived in it.
    From the mining camps, those victims in 1994 were transferred downriver (as they would be again from Mayibout 2) to Makokou General Hospital. Then arose a wave of secondary cases, focused around the hospital or in villages nearby. In one of those villages was a nganga , a traditional healer, whose house may have been a point of transmission between a certain mining-camp victim of the outbreak, seeking folk medicine, and an unlucky local person visiting the healer about something less dire than Ebola. Possibly the virus was passed by the healer’s own hands. Anyway, by the time this sequence ended, forty-nine cases had been diagnosed, with twenty-nine deaths, for a case fatality rate of almost 60 percent.
    A year later came the outbreak at Mayibout 2, second in the series. Eight months after that, the CIRMF scientists and others responded to a third outbreak, this one near the town of Booué in central Gabon.
    The Booué situation had probably begun three months earlier, in July 1996, with the death of a hunter at a timber camp known as SHM, about forty miles north of Booué. In retrospect, this hunter’s fatal symptoms were recognized as matching Ebola virus disease, though his case hadn’t triggered alarm at the time. Another hunter died mysteriously in the same logging camp six weeks later. Then a third. What sort of meat were they supplying to the camp? Probably a wide range of wild species, including monkeys, duikers, bush pigs, porcupines, possibly even (despite legal restrictions) apes. And again there were reports of chimpanzees seen dead in the forest—fallen dead, that is, not shot dead. The three early human cases seem to have been independent of one another, as though each hunter contracted the virus from the wild. Then the third hunter broadened the problem, making himself a transmitter as well as a victim.
    He was hospitalized briefly at Booué but left that facility, eluded medical authorities, went to a nearby village, and sought help there from another nganga. Despite the healer’s ministrations the hunter died—and then so did the nganga and the nganga’s nephew. A cascade had begun. During October and into succeeding months there was a wider incidence of cases in and around Booué, suggesting more person-to-person transmission. Several patients were transferred to hospitals in Libreville, Gabon’s capital, and died there. A Gabonese doctor, having performed a procedure on one of those patients, fell sick himself and, showing little confidence in his own country’s health care, flew to Johannesburg for treatment. That doctor