another, and yes indeed: She had antibodies to Hendra virus. By that time she was back on her feet, working again. She had been infected and shaken it off.
When I met her, more than a year later, she was feeling fine, apart from a little weariness and more than a little anxiety. She knew well that the case of Mark Preston—his infection during a horse postmortem, his recovery, his interlude of good health, then his relapse—cautioned against complacency that the virus had left her forever. State health officials were tracking her case; if the headaches returned, if she felt dizzy or suffered a seizure, if her nerves tingled, if she started coughing or sneezing, they wanted to know it. “I still go and see the infectious disease control specialists,” she said. “I get weighed by the Department of Primary Industries on a regular basis.” From blood tests they charted her antibody levels, which continued to fluctuate peculiarly down and up. Lately the numbers were back up. Did that portend a relapse, or did it just reflect her robust acquired immunity?
The scariest part, she told me, was the uncertainty. “It’s the fact that this disease has been around for so little that they can’t tell me whether there’s going to be any future health risk.” How would she be in seven years, ten years? How high was the chance of recrudescence? Mark Preston died suddenly after a year. Ray Unwin said his health was still “crook.” The young vet in Cairns only wanted to know, in her own case, the same thing we all want to know: What next?
II
THIRTEEN GORILLAS
8
Not many months after the events at Vic Rail’s stables, another spillover occurred, this one in Central Africa. Along the upper Ivindo River in northeastern Gabon, near the border with the Republic of the Congo, lies a small village called Mayibout 2, a sort of satellite settlement just a mile upriver from the village of Mayibout. In early February 1996, eighteen people in Mayibout 2 became suddenly sick after they participated in the butchering and eating of a chimpanzee.
Their symptoms included fever, headache, vomiting, bloodshot eyes, bleeding from the gums, hiccupping, muscle pain, sore throat, and bloody diarrhea. All eighteen were evacuated downriver to a hospital in the district capital, a town called Makokou, by decision of the village chief. It’s less than fifty miles as the crow flies from Mayibout 2 to Makokou, but by pirogue on the sinuous Ivindo, a journey of seven hours. The boat wound back and forth between walls of forest along the banks. Four of the evacuees were moribund when they arrived and dead within two days. The four bodies, returned to Mayibout 2, were buried according to traditional ceremonial practice, with no special precautions against the transmission of whatever had killed them. A fifth victim escaped from the hospital, straggled back to the village, and died there. Secondary cases soon broke out among people infected while caring for the first victims—their loved ones or friends—or in handling the dead bodies. Eventually thirty-one people got sick, of whom twenty-one died: a case fatality rate of almost 68 percent.
Those facts and numbers were collected by a team of medical researchers, some Gabonese, some French, who reached Mayibout 2 during the outbreak. Among them was an energetic Frenchman named Eric M. Leroy, a Paris-trained veterinarian and virologist then based at the Centre International de Recherches Médicales de Franceville (CIRMF), in Franceville, a modest city in southeastern Gabon. Leroy and his colleagues found evidence of Ebola virus in samples from some patients, and they deduced that the butchered chimpanzee had been infected with Ebola. “The chimpanzee seems to have been the index case for infecting 18 primary human cases,” they wrote. Their investigation also turned up the fact that the chimp hadn’t been killed by village hunters; it had been found dead in the forest and scavenged.
Four years later, I sat at a campfire near the upper Ivindo River with a dozen local men who were working as forest crew for a long overland trek. These men, most of them from villages in northeastern Gabon, had been walking for weeks before I joined them on the march. Their job involved carrying heavy bags through the jungle and building a simple camp each night for the biologist, one Mike Fay, whose obsessive sense of mission drove the whole enterprise forward. Fay is an unusual man, even by the standards of tropical field biologists: physically tough, obdurate, free-spirited, smart, and fiercely